diy solar

diy solar

few questions about solar power....

robbob2112 said:
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.
Click to expand...
sorry.. forgot to add.. drinking isnt a personal choice dude.. but if you are military, im sure you understand... you did mention guam and navy....
 
LordGarak said:
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).
Click to expand...
thank you.. but being Canadian from a colder climate, im not used to exactly SLA batteries bursting into flames... lithium.. wether it be iron or ion.. still has that key component.. lithium... hence the hesitation....
 
Hedges said:
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.

View attachment 205715

View attachment 205716



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.
Click to expand...
sorry, i forgot to ask.. HOW do i check for voltage and amperage of a solar panel simutaneously ?
 
corporal_Canada said:
sorry, i forgot to ask.. HOW do i check for voltage and amperage of a solar panel simutaneously ?
Click to expand...
Under load during use, a voltage measurement can be taken, and an amperage measurement as well.

What he is saying is taking the two specs of the panels and multiplying them out does Not give you the wattage capabilities of the panel. It gives you two maximum possibilities.
 
corporal_Canada said:
sorry.. forgot to add.. drinking isnt a personal choice dude.. but if you are military, im sure you understand... you did mention guam and navy....
Click to expand...

Oh I understand. When I lived in Guam there were basically two choices for recreation available. Drink or scuba dive. Getting sick at 60ft down and feeding the fish is something you will only ever do once. We had 4 section duty, so I went diving 3 nights then drank on the 4th. Luckily there were beaches within a 15 minute drive.

I also spent a lot of time working on my vw beetle or other guys in the barracks cars. I traded my time for beer. Pretty much all Navy bases at the time had an auto shop with tools and lifts and an old guy working there to teach you how to do anything. And it was always busy and anytime I asked someone if the could use a hand they were happy to accept.

My only advice here is find anything to do as a hobby that requires your wits about you. I had one guy that worked for me who basically came to work, went to the gym, went to the chow hall, and repeated. On payday he saved half his paycheck and split the rest between the strip club drinks and the massage parlour next door. I did spend time in the clubs myself, but only when the whole shop went out on payday. I never liked paying money to a chick that basically had no use for me besides my wallet. And the massage parlors were a place you had to make sure you wore your raincoat and put it on yourself.

I wish I had taken up swimming for exercise or running and stuck with it, I would be in a lot better shape and not have had a hip replaced and be on pills for a variety of issues.

If the CAF is anything like the US military you can tell medical you have apnea and they will evaluate and provide a machine.


Like the others have said LFP batteries are pretty safe, pretty much to have them cause a fire you have to have physical damage that causes them to vent and also have an ignition source. Something that pierces the cells which is hard to do through the abs plastic cases.

One alternate activity you could look for is a continuing education class in electricity and study to be an electrician when you get out. That is another thing I did a bit of, taking college classes. They let me interact with the local female population in a good way. Which was a difficult thing to otherwise do. This is another place to wear the raincoat, there were always locals that wanted to get married and move back to the states. Being pregnant was the easiest way to do it. Once back in the states they would commonly bring their whole family over. This wasn't really a problem in Guam, but it was a serious problem in the phillipines at the time.

I also looked at the area and did hikes and tourist things a few maybe once a month wherever I was at. The USO ran these things for us to use, but they were never full. I assume the CAF has a similar organization.

I guess there were more than two choices, just my primary two were drinking and diving.
 
Last edited:
corporal_Canada said:
sorry, i forgot to ask.. HOW do i check for voltage and amperage of a solar panel simutaneously ?
Click to expand...

If you simply connected the panel to a 12V lead-acid battery, you could measure voltage with one meter and current with another. Or even with same meter, interrupting connection in between - won't actually be simultaneous, but voltage and current should be close enough to the same during both measurements.

Trouble with that is the battery will probably be about 14V, below the 17V to 18V Vmp of the panel, so wattage calculation will be low. It will be suitable for what a PWM charge controller would get.

To measure voltage and current at maximum power point, easiest way is to use an MPPT charge controller, connected to a battery that isn't yet fully charged.

Another way to approximate it, look at label on panels and Vmp / Imp = R, the resistance that would load panel to maximum power point (under laboratory conditions of sunlight and temperature.) I did that for a panel I had, came up with 6 ohms. Connecting a couple space heaters in parallel and switching the power setting I got something close enough.

By they way, many DMM have a 3A or 10A max current scale. If PV panel puts out more it will blow the fuse. I bought a DC clamp ammeter for this.
 
Hedges said:
If you simply connected the panel to a 12V lead-acid battery, you could measure voltage with one meter and current with another. Or even with same meter, interrupting connection in between - won't actually be simultaneous, but voltage and current should be close enough to the same during both measurements.

Trouble with that is the battery will probably be about 14V, below the 17V to 18V Vmp of the panel, so wattage calculation will be low. It will be suitable for what a PWM charge controller would get.

To measure voltage and current at maximum power point, easiest way is to use an MPPT charge controller, connected to a battery that isn't yet fully charged.

Another way to approximate it, look at label on panels and Vmp / Imp = R, the resistance that would load panel to maximum power point (under laboratory conditions of sunlight and temperature.) I did that for a panel I had, came up with 6 ohms. Connecting a couple space heaters in parallel and switching the power setting I got something close enough.

By they way, many DMM have a 3A or 10A max current scale. If PV panel puts out more it will blow the fuse. I bought a DC clamp ammeter for this.
Click to expand...
with all due respect.. NONE of that made any sense to me..... can you not simply say .. connect multimeter to positive and negative and switch to THIS setting
 
the reason i wanted to TRY to connect 1 or more solar panels to the UPS is because of this indian (or bharat video) even if it doest keep the UPS battery full.. it does put something into it... but i think you all said that isnt a good idea so ill just put that idea on hold...


hope that link stays there :)
 
corporal_Canada said:
with all due respect.. NONE of that made any sense to me..... can you not simply say .. connect multimeter to positive and negative and switch to THIS setting
Click to expand...
I get how confusing this topic is to the novice.

But what you are wanting to learn is hard.

If you set your volt meter to volts and set the panel in the sun you will see the unloaded voltage the panel can produce. It should be around the VOC number on the panel.

If you then set the meter to amps, and the isc of the panel is less than the 10A of the meter, you should see the short circuit amps the panel can produce…

But to know how much POWER the panel can produce, it needs to be doing work. Charging a battery, or feeding a resistor.

Simply connecting two meters the way described above, you will see odd results depending on conditions.

There isn’t an easy step by step way to show you power output, which is why we say connecting to a charge controller and a battery is the best way to see what the panel can produce.
 
robbob2112 said:
Oh I understand. When I lived in Guam there were basically two choices for recreation available. Drink or scuba dive. Getting sick at 60ft down and feeding the fish is something you will only ever do once. We had 4 section duty, so I went diving 3 nights then drank on the 4th. Luckily there were beaches within a 15 minute drive.

I also spent a lot of time working on my vw beetle or other guys in the barracks cars. I traded my time for beer. Pretty much all Navy bases at the time had an auto shop with tools and lifts and an old guy working there to teach you how to do anything. And it was always busy and anytime I asked someone if the could use a hand they were happy to accept.

My only advice here is find anything to do as a hobby that requires your wits about you. I had one guy that worked for me who basically came to work, went to the gym, went to the chow hall, and repeated. On payday he saved half his paycheck and split the rest between the strip club drinks and the massage parlour next door. I did spend time in the clubs myself, but only when the whole shop went out on payday. I never liked paying money to a chick that basically had no use for me besides my wallet. And the massage parlors were a place you had to make sure you wore your raincoat and put it on yourself.

I wish I had taken up swimming for exercise or running and stuck with it, I would be in a lot better shape and not have had a hip replaced and be on pills for a variety of issues.

If the CAF is anything like the US military you can tell medical you have apnea and they will evaluate and provide a machine.


Like the others have said LFP batteries are pretty safe, pretty much to have them cause a fire you have to have physical damage that causes them to vent and also have an ignition source. Something that pierces the cells which is hard to do through the abs plastic cases.

One alternate activity you could look for is a continuing education class in electricity and study to be an electrician when you get out. That is another thing I did a bit of, taking college classes. They let me interact with the local female population in a good way. Which was a difficult thing to otherwise do. This is another place to wear the raincoat, there were always locals that wanted to get married and move back to the states. Being pregnant was the easiest way to do it. Once back in the states they would commonly bring their whole family over. This wasn't really a problem in Guam, but it was a serious problem in the phillipines at the time.

I also looked at the area and did hikes and tourist things a few maybe once a month wherever I was at. The USO ran these things for us to use, but they were never full. I assume the CAF has a similar organization.

I guess there were more than two choices, just my primary two were drinking and diving.
Click to expand...
well said bigguy. but i think this forum doesnt like personal chit chat so i iwill steer away from this and thank you for the advice.. and my sleep pap was free not because i served but because Canada does not charge for medical things..

well except for non emergency use of an ambulance...
 
Supervstech said:
I get how confusing this topic is to the novice.

But what you are wanting to learn is hard.

If you set your volt meter to volts and set the panel in the sun you will see the unloaded voltage the panel can produce. It should be around the VOC number on the panel.

If you then set the meter to amps, and the isc of the panel is less than the 10A of the meter, you should see the short circuit amps the panel can produce…

But to know how much POWER the panel can produce, it needs to be doing work. Charging a battery, or feeding a resistor.

Simply connecting two meters the way described above, you will see odd results depending on conditions.

There isn’t an easy step by step way to show you power output, which is why we say connecting to a charge controller and a battery is the best way to see what the panel can produce.
Click to expand...
yes but he wanted simutaneous readings. i thought it was some sort of klingon option on my multimeter i havent seen before.. i have VAC, VDC and amps on my chinese multimeter.. i dont see anything else im afraid...
 
corporal_Canada said:
well said bigguy. but i think this forum doesnt like personal chit chat so i iwill steer away from this and thank you for the advice.. and my sleep pap was free not because i served but because Canada does not charge for medical things..

well except for non emergency use of an ambulance...
Click to expand...
Teach me to offer suggestion based on having lived in similar shoes. Chit chat is fine, but I will drop it.

Hook your solar cells to that tiny SLA battery in your UPS and you will accomplish a fried battery, most likely a fried UPS and a fire if you are unlucky. Make sure to post in the 'up in smoke' forum.

Sorry, feeling snarky today.
 
robbob2112 said:
Teach me to offer suggestion based on having lived in similar shoes. Chit chat is fine, but I will drop it.

Hook your solar cells to that tiny SLA battery in your UPS and you will accomplish a fried battery, most likely a fried UPS and a fire if you are unlucky. Make sure to post in the 'up in smoke' forum.

Sorry, feeling snarky today.
Click to expand...
up in smoke lol, classic movie.. i loved it because tommy chong is or was Canadian... can i not add 50 watts solar panel to the ups battery / shouldnt fry it... and it will add power to whatever is flowing to the sine wave inverter..

unless my logic hear is wrong again , i was going to add 4 addition batteries to the ups and link in paralell to have more power during those times power cuts out..... sorry.. more battery storage not power...
 
robbob2112 said:
Teach me to offer suggestion based on having lived in similar shoes. Chit chat is fine, but I will drop it.

Hook your solar cells to that tiny SLA battery in your UPS and you will accomplish a fried battery, most likely a fried UPS and a fire if you are unlucky. Make sure to post in the 'up in smoke' forum.

Sorry, feeling snarky today.
Click to expand...
also,i was going to use the charge controller this time, wouldnt that cut off the input power if the battery is full
 
corporal_Canada said:
yes but he wanted simutaneous readings. i thought it was some sort of klingon option on my multimeter i havent seen before.. i have VAC, VDC and amps on my chinese multimeter.. i dont see anything else im afraid...
Click to expand...

What's missing is loading the PV panel to maximum power point.
You can do that with a different meter:

Fluke SMFT-1000 Multifunction PV Tester Performance Analyzer + I-V Curve Tracer

This all-in-one solar PV testing tool provides I-V curve tracing, PV system performance analysis and conforms to IEC 62446-1 standard.
www.fluke.com www.fluke.com

or



I did it with a couple DMM and electric space heaters:

diysolarforum.com

Measuring PV panel performance

I suppose I could buy a solar panel tester like Will reviewed, but that doesn't feel DIY enough to me. Besides, I'm a cheapskate, and I try to do things in the most difficult (and expensive if the equipment wasn't on hand) way. I'm presently working on an underperforming string of Sharp 165W...
diysolarforum.com diysolarforum.com
 
corporal_Canada said:
yes but he wanted simutaneous readings. i thought it was some sort of klingon option on my multimeter i havent seen before.. i have VAC, VDC and amps on my chinese multimeter.. i dont see anything else im afraid...
Click to expand...
He also said use two meters
 
Daddy Tanuki said:
only if the charge controller is set to charge that style and size of battery. some are adjustable, some are not. tread carefully.
Click to expand...
okay.. it is difficult to set anything on a charge controller that only has 3 buttons2.. but i think if i can set it to not exceed .. i dunno.. 13volts i should be golden right
 
Hedges said:
What's missing is loading the PV panel to maximum power point.
You can do that with a different meter:

Fluke SMFT-1000 Multifunction PV Tester Performance Analyzer + I-V Curve Tracer

This all-in-one solar PV testing tool provides I-V curve tracing, PV system performance analysis and conforms to IEC 62446-1 standard.
www.fluke.com www.fluke.com

or



I did it with a couple DMM and electric space heaters:

diysolarforum.com

Measuring PV panel performance

I suppose I could buy a solar panel tester like Will reviewed, but that doesn't feel DIY enough to me. Besides, I'm a cheapskate, and I try to do things in the most difficult (and expensive if the equipment wasn't on hand) way. I'm presently working on an underperforming string of Sharp 165W...
diysolarforum.com diysolarforum.com
Click to expand...
that looks high-tec.. and for that amount i can purchase a 4 wheel vehicle..... ive been eying a 1983 mercedes 200D on a nearby island.. and that can safely transport me to another location...... or.. spend.. 5 grand on a device to test a system that i want to put together just to not use land power with my computer, monitor and hopefully fridge...
 
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