few questions about solar power....

[GXMnow]

okay, need bms.. check.. but do i really need to buy 4 batteries and bms and cables and fuses ? just to run a pc and lcd monitor (and possibly a tiny fridge) during daylight hours ???

did nobody read the part i mentioned about trying to bring back THIS battery i have back to life ???using epsom salts/distilled water and a trickle charge.. i imagine that will be a hell of alot cheaper than 4x 3000 peso batteries ...and bms, wtv that is...and other things, why cant i just repair the infastructure that i already have here ?... OR... the other thing i mentioned twice... link 4x 3.2volt lithium batteries in series.. that there has slightly more capacity than a 100ah battery.. and apperantly is alot safer... just to make 1 x12v battery...


or why cant i just get a 12 to 24volt inverter.. if my battery voltage sits in between... wont it turn on anyways ? i just want power to flow from the solar panels to the 12v power bank to ups battery.. and from there it should harmlessly power a pc a monitor and who knows, maybe a tiny fridge ?

The power output of solar panels is not consistent. The battery is needed to stabilize the voltage under varying load. To be safe, the battery must be able to accept the maximum current the solar panels can produce. This can happen if you are not drawing a load near noon. And the battery also needs to be able to supply your maximum power draw because you can lose output from the solar panels from a shadow due to a passing cloud or even an airplane. A decent battery is important.

I didn't address reviving your battery because it does not work. We have told you several times, it's done. You need a new battery.

You need an inverter that runs at the correct voltage for the battery in use. Just because you pulled the battery voltage up to 18 volts does not mean it will run an 18 volt inverter. The battery is not capable of supplying any current at that elevated voltage. It is up there because the battery is shot, dead, ruined, no more. Once there is any load on the battery the voltage will drop like a rock.

If you get a good quality MPPT charge controller, it will regulate and hold it's output voltage at the absorb then float voltage settings. That could run an inverter as long as the light on the panels is enough to make more power than you are trying to use. But again, if the battery can't maintain the voltage, it will shut down as soon as there is any shadow on the solar panels. Every decent charge controller says to have a good battery connected BEFORE you connect the solar panels. The reason is so the charge controller has somewhere to send the energy. If you are only going to run things when the sun is shining, you don't need a very large battery, but it still needs to be able to handle the currents. Lead acid batteries are horrible as they can only handle a 0.1 or maybe 0.2C charge rate. So a 100 amp hour lead acid battery maxes out at just 20 amps of charge current.

The Lithium LFP battery shown by @robbob2112 above can take 60 amps in and put out 100 amps. It has the BMS already inside the battery. If something goes wrong, like wrong settings or a failed charge controller, it will protect itself and save the cells.

Having a weak battery can actually damage the inverter. Electrons move fast. An inverter making 50 or 60 Hz AC power is actually having to pull current then not pull current at double those frequencies, so 100 or 120 times a second, the load is going from nearly double the output power to no power. The power source (THE BATTERY) needs to be able to hold a steady voltage while that load current is constantly changing. This is called "Ripple Current" and again, Lead Acid batteries are bad at that. And with a charge controller, it get's even worse as it is actually switching from charging to discharging at the double the AC frequency rate. All inverters have some filter capacitors to help smooth this out, but the bulk of it still ends up at the battery. This issue is not as bad with high frequency inverters as they have a second stage of filtering, but the ripple is still there. My large low frequency inverter shows near the full AC load power as AC current ripple at the battery input.

What battery is in your UPS?
If you get a quality MPPT charge controller, and set it to the correct battery settings, it would be far more efficient to have it directly charge the UPS battery. Then you are only doing 1 conversion from DC to AC to run your loads. What you have been asking for is the take DC charging a damaged battery, then run an inverter to make AC, to then charge a UPS battery, converting to DC, then the UPS inverts it back to AC again. That is a lot of losses.

The solar panels you showed are not what they claim to be. They are fake labels and maybe 50 watts each, 100 if you are really lucky. And in the real world, you might be getting even less power if the panels are not at ideal angles. You are probably making less than 1,000 watt hours a day, even when the sky is clear and sunny. I showed you my array. The 10 panels in the pic make only 5,000 watt hours on a good day. Add in my second 1,000 watt row, and my best production day so far just topped 10,000 watt hours. My Victron charge controller tells me exactly what the panels are doing.

How many watts does the computer, monitor, and fridge draw? My guess of 1,000 watt hours might be a bit off, but if you take that 1,000 / watts, it will give you a rough idea of hours of run time. If it runs longer, the solar panels did better. If it turns off sooner, they did worse.

 

[billvon]

okay, need bms.. check.. but do i really need to buy 4 batteries and bms and cables and fuses ? just to run a pc and lcd monitor (and possibly a tiny fridge) during daylight hours ???

Nope. You could just use a single 12V battery. Note that 90% of your energy use will come from your "possibly a tiny fridge." If you unplug it at night it will be a lot easier of course.

why cant i just repair the infastructure that i already have

You can try. You will probably be unsuccessful.

or why cant i just get a 12 to 24volt inverter

Why do you need 24V out? Note that you CANNOT use a DC/DC converter on the output of a solar array, since unmodified DC/DCs have a negative impedance at their input, and that doesn't work with current limited sources like solar panels. You can get a DC/DC with a modified (solar-capable) input impedance; these are called MPPT controllers.

 

[corporal_Canada]

Once a battery is toast it is toast - the plates have spikes sticking out from them into the next plate shorting at least one cell and probably more. No amount of salt, water, acid, or any other thing will bring it back to life or or to its regular capacity. I know you want to try all the "tricks" on the internet to revive it but those aren't going to give you battery you can push current in and out of they might give you voltage that works for a short time but no real current out of it.
That is a problem with lead acid batteries -


The battery you list is 12V 100AH JSLII-TF100-12 battery -- this shows as a sealed lead acid (SLA) battery - that means it has a 1-way vent in it to let it off-gass when you over discharge it or over charge it. Max recommeneded DOD on this is 50% which means 50ah. 12 x 50 = 600wh. String 4 together and you will get 1200wh. The other thing about sealed lead acid batteries is they are sealed and you shouldn't be able to take the top off without damging them. Note - a lot of power put into a SLA is expended as heat while you charge - for yours it is about 40% of the energy put in. So if you put in 100watts only 60watts is stored and 40watts is heat.

Max charge current you can push through these batteries is 11.25amps. If you push more you will bulge the sides and ruin them while overheating and venting. Charge voltage is 14.4 volts.

So say you get 4 and wire in parallel that means you can push 40amps at 14.4 volts. Once they get full they will limit the charge current because their internal resistance will rise. This is a characteristic of lead acid batteries. If you raise the voltage high enough it will keep pushing current and the battery will be destroyed.

So your SCC (MPPT) should have a lead acid setting or be programable. If you string them in series for 24v or 48v your wire size will be smaller but you have to have an equalizer to keep them balanced. and your charge current will be limited to the orginal 11.25 amps. Same power either way but it matters how your SCC is programed.


For inverters you can buy the cheap HF junk and you will buy them and buy them. Nothing wrong with a HF inverter, but spend a bit more and get a quality one. Many of the super cheap ones say they are rated for 1000watts, but will only do 250w continously. The shady vendors will list the wattage as 4x actual capacity and say it will surge to that. Reality is if you surge to that for more than a fraction of a second it will blow fuses if you are lucky and if you can replace that verse junking it. If you are unlucky it will let the magic blue smoke out and it is scrap metal and junk.


You might be able to get away with a smaller battery like a 12v50ah LFP but the price is so close to the 100ah version I would get that. P9900

12v 50Ah 12v 100ah 24v 100ah LifePo4 xpower battery | Lazada PH

battery for solar panel 12v 100ah. motolite solar master battery. lithium ion battery 12v 200ah. lithium battery 12v for solar. lifepo4 battery 12v100ah set. Specifications For 50ah Xpower. Normal Voltage: 12.8V. Working Voltage: 10V14.6V. Normal Capacity: 50Ah. Max. Charging Current: 31A. Max...

www.lazada.com.ph

At P3000 per battery x 4 = 12000 - look at this -

lifepo4 battery 12v 100ah/12v 150Ah & 24v 100ah/24v 150Ah/48v 100ah | Lazada PH

battery for solar panel 12v 100ah. lithium batteries 12v for solar. sinopoly lifepo4 battery 90ah. lithium battery 12v for solar. lithium ion battery 12v 200ah. Lithium iron phosphate battery is characterised by outstanding durability, current performance and charging speed. It also has a longer...

www.lazada.com.ph

P12500 - sure is close in price and you get far greater capacity to use. 60 amp charge, 100amp discharge - has a BMS built into it.

View attachment 205540

okay, thank you for reading everything.. i understand that my big 12v battery is kaput (dead)... here is another possibility... inside my ups is a 12volt 9ah ups battery... can i not just plug the solar panels (charge controller this time) into that ?
oh sorry i missed your final question.. pc is an apu that draws 65watts...plus several harddrives... so lets say 150 watts.. monitor has zer clear indication anywhere.. it is a 23" lcd monitor.. so i will say 50 watts..

the petite refridgerator claims to only pull 55 watts

 

[Hedges]

You have nothing to start with, so start over.

Those panels are up to maybe 60W +/-, not 400W.
Might be good for maintaining a car battery, if you add a voltage regulator.

Expect 120 to 200W per square meter (lab conditions), 0.75 to 0.85 times that under typical full sun.

Take a look at sample systems Will suggests, top of DIYSolarForum page.
Decide what performance you want, tentatively select a system, and create a posting listing/linking what you're consider and describing what you want to power & how long. Then forum members can critique it.

 

[corporal_Canada]

You have nothing to start with, so start over.

Those panels are up to maybe 60W +/-, not 400W.
Might be good for maintaining a car battery, if you add a voltage regulator.

Expect 120 to 200W per square meter (lab conditions), 0.75 to 0.85 times that under typical full sun.

Take a look at sample systems Will suggests, top of DIYSolarForum page.
Decide what performance you want, tentatively select a system, and create a posting listing/linking what you're consider and describing what you want to power & how long. Then forum members can critique it.

thank you.. if i need to start over i will look at solar bundles that have no battery included..... i m naturally just looking for cheaper alternatives because global economy sucks... so battery toast.. i get that.. inverters.. all 3.. garbage.. no big deal.. but i still have a UPS with a battery and sine wave inverter in it and i still have 3 solar panels.. wither 300 or 60 watts.. they produce something to be able to cook a battery...

 

[corporal_Canada]

Nope. You could just use a single 12V battery. Note that 90% of your energy use will come from your "possibly a tiny fridge." If you unplug it at night it will be a lot easier of course.

You can try. You will probably be unsuccessful.

Why do you need 24V out? Note that you CANNOT use a DC/DC converter on the output of a solar array, since unmodified DC/DCs have a negative impedance at their input, and that doesn't work with current limited sources like solar panels. You can get a DC/DC with a modified (solar-capable) input impedance; these are called MPPT controllers.

i never said 24v out.. i meant 12 to 24v range input for any inverter to actually come on...since my battery is sitting above the 12volt threshold...

 

[corporal_Canada]

The power output of solar panels is not consistent. The battery is needed to stabilize the voltage under varying load. To be safe, the battery must be able to accept the maximum current the solar panels can produce. This can happen if you are not drawing a load near noon. And the battery also needs to be able to supply your maximum power draw because you can lose output from the solar panels from a shadow due to a passing cloud or even an airplane. A decent battery is important.

I didn't address reviving your battery because it does not work. We have told you several times, it's done. You need a new battery.

You need an inverter that runs at the correct voltage for the battery in use. Just because you pulled the battery voltage up to 18 volts does not mean it will run an 18 volt inverter. The battery is not capable of supplying any current at that elevated voltage. It is up there because the battery is shot, dead, ruined, no more. Once there is any load on the battery the voltage will drop like a rock.

If you get a good quality MPPT charge controller, it will regulate and hold it's output voltage at the absorb then float voltage settings. That could run an inverter as long as the light on the panels is enough to make more power than you are trying to use. But again, if the battery can't maintain the voltage, it will shut down as soon as there is any shadow on the solar panels. Every decent charge controller says to have a good battery connected BEFORE you connect the solar panels. The reason is so the charge controller has somewhere to send the energy. If you are only going to run things when the sun is shining, you don't need a very large battery, but it still needs to be able to handle the currents. Lead acid batteries are horrible as they can only handle a 0.1 or maybe 0.2C charge rate. So a 100 amp hour lead acid battery maxes out at just 20 amps of charge current.

The Lithium LFP battery shown by @robbob2112 above can take 60 amps in and put out 100 amps. It has the BMS already inside the battery. If something goes wrong, like wrong settings or a failed charge controller, it will protect itself and save the cells.

Having a weak battery can actually damage the inverter. Electrons move fast. An inverter making 50 or 60 Hz AC power is actually having to pull current then not pull current at double those frequencies, so 100 or 120 times a second, the load is going from nearly double the output power to no power. The power source (THE BATTERY) needs to be able to hold a steady voltage while that load current is constantly changing. This is called "Ripple Current" and again, Lead Acid batteries are bad at that. And with a charge controller, it get's even worse as it is actually switching from charging to discharging at the double the AC frequency rate. All inverters have some filter capacitors to help smooth this out, but the bulk of it still ends up at the battery. This issue is not as bad with high frequency inverters as they have a second stage of filtering, but the ripple is still there. My large low frequency inverter shows near the full AC load power as AC current ripple at the battery input.

What battery is in your UPS?
If you get a quality MPPT charge controller, and set it to the correct battery settings, it would be far more efficient to have it directly charge the UPS battery. Then you are only doing 1 conversion from DC to AC to run your loads. What you have been asking for is the take DC charging a damaged battery, then run an inverter to make AC, to then charge a UPS battery, converting to DC, then the UPS inverts it back to AC again. That is a lot of losses.

The solar panels you showed are not what they claim to be. They are fake labels and maybe 50 watts each, 100 if you are really lucky. And in the real world, you might be getting even less power if the panels are not at ideal angles. You are probably making less than 1,000 watt hours a day, even when the sky is clear and sunny. I showed you my array. The 10 panels in the pic make only 5,000 watt hours on a good day. Add in my second 1,000 watt row, and my best production day so far just topped 10,000 watt hours. My Victron charge controller tells me exactly what the panels are doing.

How many watts does the computer, monitor, and fridge draw? My guess of 1,000 watt hours might be a bit off, but if you take that 1,000 / watts, it will give you a rough idea of hours of run time. If it runs longer, the solar panels did better. If it turns off sooner, they did worse.

sorry, tiny correction.. 12v 7ah inside the ups...

 

[gotbeans]

yeah.. and this will tickle your brain too.. each solar panel only cost me 30$cad.... .. but only 1 actually came with a charge controller...

well that isn't surprising, since they're probably like 50 watt panels. They're expensive as hell imo

yes, im aware that these solar panels arent huge, but im alot closer to China than you are at the moment (i think).. so Philipines has slightly quicker access to the new developements coming out of china than north america...

I'd bet you north america gets the stuff faster than any other place does lol

You have nothing to start with, so start over.

Those panels are up to maybe 60W +/-, not 400W.
Might be good for maintaining a car battery, if you add a voltage regulator.

Expect 120 to 200W per square meter (lab conditions), 0.75 to 0.85 times that under typical full sun.

Take a look at sample systems Will suggests, top of DIYSolarForum page.
Decide what performance you want, tentatively select a system, and create a posting listing/linking what you're consider and describing what you want to power & how long. Then forum members can critique it.

Yep I agree, kept asking him for pages what he actually has. I think all of it is just throw-away

 

[corporal_Canada]

well that isn't surprising, since they're probably like 50 watt panels. They're expensive as hell imo

well that is depressing because i remember the night i received my first inverter and i powered my fan and laptop for 12 hours straight, everyone down the street could hear me giggling histarically

I'd bet you north america gets the stuff faster than any other place does lol

i wont argue with you on that dude...

Yep I agree, kept asking him for pages what he actually has. I think all of it is just throw-away

even if the solar panels only produce 50 watts.. they still produce something... i did test one solar panel.. volts and amps and came to the answer.. i was getting 100 watts at that exact moment...

 

[gotbeans]

well that is depressing because i remember the night i received my first inverter and i powered my fan and laptop for 12 hours straight, everyone down the street could hear me giggling histarically

the sun isn't out at night, so you were just running on battery

even if the solar panels only produce 50 watts.. they still produce something... i did test one solar panel.. volts and amps and came to the answer.. i was getting 100 watts at that exact moment...

yea 100 watts is more realistic than 400

 

[Hedges]

even if the solar panels only produce 50 watts.. they still produce something... i did test one solar panel.. volts and amps and came to the answer.. i was getting 100 watts at that exact moment...

Speaking as an EE here ...

I don't think you tested "volts" and "amps" at the same exact moment. (I think you did so sequentially)
Do that, recompute watts, tell us what you find.

 

[robbob2112]

okay, thank you for reading everything.. i understand that my big 12v battery is kaput (dead)... here is another possibility... inside my ups is a 12volt 9ah ups battery... can i not just plug the solar panels (charge controller this time) into that ?
oh sorry i missed your final question.. pc is an apu that draws 65watts...plus several harddrives... so lets say 150 watts.. monitor has zer clear indication anywhere.. it is a 23" lcd monitor.. so i will say 50 watts..

the petite refridgerator claims to only pull 55 watts

That tiny battery is just to small to be any good for charging. If you hook it up in place of your current large battery it will just die a bad death and within hours. The little battery is good for no more than 1~2 amps charge current and maybe 5 amps discharge. It is intended to be fully charged and sit there most of the time. In the event of a power outage it will provide 5 to 15 minutes power depending on load.

 

[robbob2112]

okay, thank you for reading everything.. i understand that my big 12v battery is kaput (dead)... here is another possibility... inside my ups is a 12volt 9ah ups battery... can i not just plug the solar panels (charge controller this time) into that ?
oh sorry i missed your final question.. pc is an apu that draws 65watts...plus several harddrives... so lets say 150 watts.. monitor has zer clear indication anywhere.. it is a 23" lcd monitor.. so i will say 50 watts..

the petite refridgerator claims to only pull 55 watts

for a small desktop you will draw around 80~110 watts for the motherboard, 10~15watts per memory stick, 30~110watts for the CPU, and between 3 and 20 watts per drive. They start up and take extra power then once they are spinning they take less. Depends on the drives.

So on the low end you are looking at a couple hundred watts for a desktop machine when not in idle. When in power save idle it goes down to about 30watts. A LED monitor varies by size and brightness setting but is typicaly between 10watts in idle and 60watts full on. A gaming monitor can draw twice that because of the faster refresh rage.

Laptops can vary from 30watts to 150watts. Everything is designed around being small and low power and low heat generation. And they all have a built in battery. So they may spike higher than the power supply connected and draw energy from the battery when there is high demand on the CPU/memory/disk/ssd/etc.... If the battery is not present or is bad and doesn't keep a charge the laptop just runs slower because the CPU isn't able to run full speed.

Your 55watt fridge may take as much as 300watts if it is the type with a compressor in it. You can tell by looking at the back or the inside bottom will have 1/2 the shelf bumped out and the compressor is behind it. The way it works is the compressor cycles on and runs a while, then turns off. Everytime it turns on it needs that large spike of power for a fraction of a second. When the compressor is not running the draw is nearly 0 watts.

If it is a Pizo element to cool it the current draw is lower and there is no spike, but it runs more of the time. Look on the back and if you see 1 or two fans in the middle with what looks likeheatsinks around them. That is a pizo cooler element. It can cycle one or both if it has 2 of them. Once the fridge is cool enough it turns them off and draws nearly 0 watts.


I attached a drawing of what I built as a CPAP backup. For your purposes the charger would be replaced by the MPPT and the shunt is not required but is a nice to have. The disconnects are totally options since you do not intend to carry it around. This unit weighs around 25lbs and I have it mounted inside a sewing box I picked up at a thrift shop for a couple of bucks.

My cost here in the states was $498 for all the components for the battery box and $334 for the Victron Phoenix inverter. This setup will run my full sized fridge for 14hours or so. The phoenix handles the compressor starts no problem because it is a low frequency inverter. I could get a HF inverter that would work just as well, but I would probably need something with a higher wattage rating.

You should be able to get all the parts I used cheaper since they are all mfg'd in China.

Note - I use a MRBF fuse and holder on the battery post - don't skimp and not use a fuse. If you accidently short something or hook up something wrong it is much cheaper to replace a fuse than to replace wires or gear. And you will read it over and over here - fuses are to protect wires only.


Question to the folks much more familar with solar panels and MPPT - what size MPPT would you add instead of the charger and what solar panels to keep it running with say 600watts load? The idea being to run all day and then have a full charge when night falls? And pls explain how you come up with what you say.... I am thinkiing of adding panels to this as a next step in my solar journey.

 

[corporal_Canada]

for a small desktop you will draw around 80~110 watts for the motherboard, 10~15watts per memory stick, 30~110watts for the CPU, and between 3 and 20 watts per drive. They start up and take extra power then once they are spinning they take less. Depends on the drives.

So on the low end you are looking at a couple hundred watts for a desktop machine when not in idle. When in power save idle it goes down to about 30watts. A LED monitor varies by size and brightness setting but is typicaly between 10watts in idle and 60watts full on. A gaming monitor can draw twice that because of the faster refresh rage.

Laptops can vary from 30watts to 150watts. Everything is designed around being small and low power and low heat generation. And they all have a built in battery. So they may spike higher than the power supply connected and draw energy from the battery when there is high demand on the CPU/memory/disk/ssd/etc.... If the battery is not present or is bad and doesn't keep a charge the laptop just runs slower because the CPU isn't able to run full speed.

Your 55watt fridge may take as much as 300watts if it is the type with a compressor in it. You can tell by looking at the back or the inside bottom will have 1/2 the shelf bumped out and the compressor is behind it. The way it works is the compressor cycles on and runs a while, then turns off. Everytime it turns on it needs that large spike of power for a fraction of a second. When the compressor is not running the draw is nearly 0 watts.

If it is a Pizo element to cool it the current draw is lower and there is no spike, but it runs more of the time. Look on the back and if you see 1 or two fans in the middle with what looks likeheatsinks around them. That is a pizo cooler element. It can cycle one or both if it has 2 of them. Once the fridge is cool enough it turns them off and draws nearly 0 watts.


I attached a drawing of what I built as a CPAP backup. For your purposes the charger would be replaced by the MPPT and the shunt is not required but is a nice to have. The disconnects are totally options since you do not intend to carry it around. This unit weighs around 25lbs and I have it mounted inside a sewing box I picked up at a thrift shop for a couple of bucks.

My cost here in the states was $498 for all the components for the battery box and $334 for the Victron Phoenix inverter. This setup will run my full sized fridge for 14hours or so. The phoenix handles the compressor starts no problem because it is a low frequency inverter. I could get a HF inverter that would work just as well, but I would probably need something with a higher wattage rating.

You should be able to get all the parts I used cheaper since they are all mfg'd in China.

Note - I use a MRBF fuse and holder on the battery post - don't skimp and not use a fuse. If you accidently short something or hook up something wrong it is much cheaper to replace a fuse than to replace wires or gear. And you will read it over and over here - fuses are to protect wires only.


Question to the folks much more familar with solar panels and MPPT - what size MPPT would you add instead of the charger and what solar panels to keep it running with say 600watts load? The idea being to run all day and then have a full charge when night falls? And pls explain how you come up with what you say.... I am thinkiing of adding panels to this as a next step in my solar journey.

a spinning hdd takes 35watts at all times and i have one... including 2 ssd's and that is why i rounded up the tower use at 150 watts... however CAF is sending me a replacement... MSI gf something.... it sais it pulls 130 to 180 watts (laptop sorry) but that is based on 110 volt AC. so i dont know if its the same number....i honestly dont need my CPAP here. i drink so heavily thati dont go to sleep i just wake up somewhere ..... but your device looks very cool...

and if the ups battery isnt enough for any of my solar panels.. what if i buy 2 or 3 more and paralel link them ?

how many of these ups batteries do i need to lego together to safely use all 3 of my solar panels ? or at least 1 ?
12v 7ah by the way

and my tiny fridge is NOT a pizo cooler that i am aware of... it only cost me 120-140$cad... and i am aware that the surge pull of the evaporator and compressor can pull as much as 300 or more watts but as you said most of the time it does nothing. so the 55 watts is rounded off and the total includes the time it pulls nothing and the time it pulls 300 or more watts, i did order a digital wattometer to have all these digits more specific... and oh yes i will be measuring everything

and sorry, CAF is Canadian Armed Forces

 

[corporal_Canada]

Speaking as an EE here ...

I don't think you tested "volts" and "amps" at the same exact moment. (I think you did so sequentially)
Do that, recompute watts, tell us what you find.

no not at the same exact momement... it took a few moments to switch the multimeter frm VDC to amps.. if you have a more precise way, please educate me sir...

 

[Hedges]

OK, glad you're open to it.

PV panels have specified Voc open circuit voltage, Isc short circuit current, Vmp maximum power point voltage, Imp maximum power point current.
Those measurements are taken with panel at 25C room temperature, flashed briefly with one standard sun, 1000W/m^2.
In other words, not allowing the panel to warm up in the sun, because current will be reduced when it gets warm and leaks current internally.

What you measured was Voc (zero current) and Isc (zero volts). Under some sun and temperature conditions.
If loaded down to Vmp (about 15% lower voltage than Voc), it would produce Imp (about 15% less than Isc.)
W = Vmp x Imp.
You never get Voc and Isc at the same time, so multiplying them together does not give a power number that is achievable.







A "12V" PV panel might be about 22Voc, 18Vmp. There are testers for PV output (similar to battery testers the auto store uses.)
If you had 6V batteries, three in series would be around 18Vmp, might be a suitable load.
Or, apply a resistive load. I used some electric radiators, two in parallel to test a "24V" 165W PV panel.
Or if you have an MPPT charge controller, and you connect it to a battery that needs recharging (or battery plus load), then you could measure PV panel voltage and current at maximum power point, Vmp & Imp.

 

[robbob2112]

how many of these ups batteries do i need to lego together to safely use all 3 of my solar panels ? or at least 1 ?
12v 7ah by the way

As long as you stick with small lead acid you will have issues. The chemistry can't take high charge rates or voltages. Your solar panels will produce a daytime charge current higher than it can take. The small lead acid can't even out the voltage and current swings from cloud, jets, trees (if any). You would need around 23 of those tiny batteries wired in parallel. One bad connection among those and you have a fire waiting to happen.

Tough love time here - what you have won't work to do what you want. The only parts that are reusable are the panels and even then you will need more in the end.

I get it, money is tight.

So plan and make a list of what you need. Read everything you can here and learn. Do a design and run a parts list by the folks here. Everyone here wants to help.

Save your money and spend it wisely. Spend wisely and on quality and you you won't have to buy the same item 3 times because the cheap stuff burns up.

This is the reason everyone with any experience here will tell you not to buy anything until you have a complete plan.

To start over spend your money on a battery, fuse, and a MPPT. If you have a PWM for your panels that works you can use it in the short term. What you absolutle can not do is hook panels straight to a battery. And unlike the lead acid battery you won't fry the a LiFePO4 battery. This gets you a method you will get a battery and a way to charge it. If any of your current inverters work you can hook them up and use the power.

For the CPAP heavy drinking will make your apnea much worse. That comes with all the health issues in spades. But, like your heavy drinking it is a personal choice and we aren't here to judge.

 

[corporal_Canada]

As long as you stick with small lead acid you will have issues. The chemistry can't take high charge rates or voltages. Your solar panels will produce a daytime charge current higher than it can take. The small lead acid can't even out the voltage and current swings from cloud, jets, trees (if any). You would need around 23 of those tiny batteries wired in parallel. One bad connection among those and you have a fire waiting to happen.

Tough love time here - what you have won't work to do what you want. The only parts that are reusable are the panels and even then you will need more in the end.

I get it, money is tight.

So plan and make a list of what you need. Read everything you can here and learn. Do a design and run a parts list by the folks here. Everyone here wants to help.

Save your money and spend it wisely. Spend wisely and on quality and you you won't have to buy the same item 3 times because the cheap stuff burns up.

This is the reason everyone with any experience here will tell you not to buy anything until you have a complete plan.

To start over spend your money on a battery, fuse, and a MPPT. If you have a PWM for your panels that works you can use it in the short term. What you absolutle can not do is hook panels straight to a battery. And unlike the lead acid battery you won't fry the a LiFePO4 battery. This gets you a method you will get a battery and a way to charge it. If any of your current inverters work you can hook them up and use the power.

For the CPAP heavy drinking will make your apnea much worse. That comes with all the health issues in spades. But, like your heavy drinking it is a personal choice and we aren't here to judge.

okay understood, so if i link 5 ups batteries in parallel, i cannot use the solar panels i have (using the charge controller this time....)or mppt.... im just very iffy about lithium batteries after all those hover boards caught fire years ago.. and i even bought a small power bank with lithium d cells umm 18680 bbatteries tapd together... .. now i just use it for the modem .. not to lose internet while there is a brown out...but.. it keeps bouncing from 100 to 40 percent on the front digital readout.. even when plugged into landpower........ i peaked inside it is the infamous lithium that China has been getting from DRC (congo).. so.. its garbage.. so.. 2 sla batteries or i need 4 ? and mppt.. and inverter with higher input voltage...or.. start getting those lithium ractangles that read 3.2 volts ?.. 1 is only 20-25$..... 4 of them.. will give me a 12v battery.. so stick with that or have more ? liike 24 or 48volts ?

 

[LordGarak]

Lithium Iron Phosphate(LiFePO4) are much safer than Lithium Ion and Lithium Polymer batteries that have the thermal runaway problems that cause major fires.

That said messing with high current is a major fire risk. Running lead acid batteries at the wrong voltages, without the right fuses and poor terminations can be much more dangerous.

Lithium Iron Phosphate is one of the safer ways to go provided you have a reputable battery management system(BMS), good terminations(wire connections) and proper overcurrent protection of the wire(fuses, breakers).

 

[Supervstech]

Lithium Iron Phosphate(LiFePO4) are much safer than Lithium Ion and Lithium Polymer batteries that have the thermal runaway problems that cause major fires.

That said messing with high current is a major fire risk. Running lead acid batteries at the wrong voltages, without the right fuses and poor terminations can be much more dangerous.

Lithium Iron Phosphate is one of the safer ways to go provided you have a reputable battery management system(BMS), good terminations(wire connections) and proper overcurrent protection of the wire(fuses, breakers).

ANY battery technology that uses Lithium IS a lithium ion battery.

All of them are correctly called lithium ion.

Lithium iron phosphate and their variants use a different electrolyte that does not contain an oxidizer and as such will not auto ignite, or explode.

Most of the cobalt or nickel containing cells with a 3.7v energy often called lithium polymer, or just lithium ion incorrectly as an identifier of the type… when it should be called LiNMC or similar use a HIGHLY flammable electrolyte that strongly reacts to temperature, ampdraw, or short circuit and self ignite or explode on their own…

LFP does NOT self ignite, nor does it burn without being fed oxygen, and extinguishes the same as wood, when it is on fire from a high heat source like being in a burning building…