Explain to me as to a toddler

[Tamacat]

We finally went solar after 7 years of vanlife. Eco-Worthy 2 100 watt panels full kit w a 12.8v 50ah battery, and a 600 watt inverter, with a 30A PWM controller. First thing we did was toss the PWM for a Renogy Rover 30A.
24 hours plus, all was good (except parking in the hot sun) but then last night, instead of lasting the four hours it had the previous night, the battery drained on its own, from 11.7 with the inverter off, to 7.4. I gave up and we hit the sack. This morning the whole thing was dead! The Renogy has a sort of jump start in it? After 2 hours the system limped to life, with an ACr code (which I took an hour to find out means the controller is knocking on the battery's door trying to wake it up) then the system began working again. I made absolutely sure everything was set correctly, connected correctly and the DC load was shut off. We charged the battery up to the 13.1 it was at on initial hook up before turning on the inverter, and plugging in our 45-60 watt pulling fridge, and all seems okay, but any insight would be appreciated. Thank you!

 

[Solarcabin Channel]

What type of battery are you using?

Sounds like your battery is undersized for your load.

At 11.7 volts your battery was barely charged and you must be using a direct DC load to run it to 7.4 volts and that is an absolute disaster for any battery. Your BMS should not have allowed it to ever get that low.

I use 12 volt fridge like you and you really need at least a 100Ah battery.

200 watts of solar will recharge that in about 7-8 hours of good sunshine but if you are not getting good sun you probably need another 200 watts of solar.

 

[mikefitz]

2 100 watt panels full kit w a 12.8v 50ah battery, and a 600 watt inverter

I assumeyou are running an AC fridge via an inverter. Not enough battery Ah, 50 Ah is too low a capacity to drive fridge and Inverter overnight. You need 100Ah of battery without running an inverter and 200Ah with an inverter. These are the minimum . Overnight the Inverter and fridge power could exceed the 600 watt hours in the 50Ah battery.
200 watts of panels will deliver on a good day 1000 watt hours. Ideally more panels are needed.
The Renogy Rover on default lithium setting, is not ideal where you have a load during daytime.

 

[Tamacat]

What type of battery are you using?

Sounds like your battery is undersized for your load.

At 11.7 volts your battery was barely charged and you must be using a direct DC load to run it to 7.4 volts and that is an absolute disaster for any battery. Your BMS should not have allowed it to ever get that low.

I use 12 volt fridge like you and you really need at least a 100Ah battery.

200 watts of solar will recharge that in about 7-8 hours of good sunshine but if you are not getting good sun you probably need another 200 watts of solar.

Eco-worthy that came w the kit. Nothing on the DC. Just the inverter. The thing is, the inverter turns off at 11.7. So we switch to a portable power box at night. There was Nothing on the battery but the lights on the controller after it hit 11.7. the DC is turned off, we don't have a fuse box yet to hook it to.
It woke up this morning, and has behaved all day. Weird, because Tuesday, it behaved all day, inverter turning off at low voltage, no problem. And So Cal has hellish sun. Which is why I've been against solar for so long preferring the shade. But here we are w 6$ a gallon gas.
We do plan on more power. This is a start. So basically something drained the battery or it's bad and not holding a charge. Thank you for the insight!

 

[Tamacat]

I assumeyou are running an AC fridge via an inverter. Not enough battery Ah, 50 Ah is too low a capacity to drive fridge and Inverter overnight. You need 100Ah of battery without running an inverter and 200Ah with an inverter. These are the minimum . Overnight the Inverter and fridge power could exceed the 600 watt hours in the 50Ah battery.
200 watts of panels will deliver on a good day 1000 watt hours. Ideally more panels are needed.
The Renogy Rover on default lithium setting, is not ideal where you have a load during daytime.

We use a 660 watt portable power box at night and for months, it's been fine, usually with 20 to 40% left over in the morning. Some cooler nights we have 60% in the morning.
What should I set the battery control for for the day time load until we get sorted? And would it be best to get the fridge hooked to a DC fuse box set up after we get 2 more panels and another battery?

 

[Doggydogworld]

Is this your battery?

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How many Wh (or Ah) is your "660W portable power box"?

The Rover draws a little current from the battery even after the inverter shuts down. It's not much, but you're down to 1-3% SOC when the inverter shuts off at 11.7V.

You may need to balance the cells in your battery. I don't know why you see 7V. Your battery BMS should disconnect around 10V. Might be worth it to charge it all day with no load, then see if it runs the fridge all night.

 

[mikefitz]

Please can you give more detail about the fridge, is a 12v DC powered compressor fridge ?

If , as you point out, if the fridge ran overnight on a 660 watt power pack , then a 50Ah fully charged battery should also perform in a similar way.
It's possible the battery is not being fully charged, under charge it need to get to over 14 volts.

 

[Tamacat]

Battery: no, ours is the 12.8v 50ah one.

How many Wh (or Ah) is your "660W portable power box"?

Not sure about the Ah but thing is 660 watts.

The Rover draws a little current from the battery even after the inverter shuts down. It's not much, but you're down to 1-3% SOC when the inverter shuts off at 11.7V.

That's what I was thinking last night, It was the only thing draining power.

You may need to balance the cells in your battery. I don't know why you see 7V. Your battery BMS should disconnect around 10V. Might be worth it to charge it all day with no load, then see if it runs the fridge all night.

Will give it a try, because Tuesday it ran fine, Wednesday night was the sudden OMG drain. Two more weeks and we'll get the extra 12.8v 50ah to make 100 ah, but the 50ah came with the kit. Thank you!

 

[Tamacat]

Please can you give more detail about the fridge, is a 12v DC powered compressor fridge ?

It's a Koree brand 12v 50q fridge freezer, pulling 40-60 watts when it cycles on. It's a very good fridge.

If , as you point out, if the fridge ran overnight on a 660 watt power pack , then a 50Ah fully charged battery should also perform in a similar way.
It's possible the battery is not being fully charged, under charge it need to get to over 14 volts.

Im not sure this thing goes over 14 volts. I'll have to ask the company, because all the reading I've done is so conflicting about the safe full charge. It could also be cooler nights help a lot. The size of the kit was based on "it can run a 12v fridge" in reviews, so we had our fingers crossed. By January we'll have 2 more panels as well.

 

[Solarcabin Channel]

It's a Koree brand 12v 50q fridge freezer, pulling 40-60 watts when it cycles on. It's a very good fridge.

Im not sure this thing goes over 14 volts. I'll have to ask the company, because all the reading I've done is so conflicting about the safe full charge. It could also be cooler nights help a lot. The size of the kit was based on "it can run a 12v fridge" in reviews, so we had our fingers crossed. By January we'll have 2 more panels as well.

A 50Ah can run a 12 volt fridge but depends on ambient temp and if you are opening that fridge a lot.

I run 2 similar12 volt fridge/freezers full time at my cabin. One is a fridge the other a freezer and the freezer unit runs considerably more often because it has to pull the temp down a lot farther.

I run one off a 100Ah AGM and 200 watts of solar but if I don't get good sunlight that system will struggle. The other I run off 400 watts and 200Ah and never an issue.

 

[Tamacat]

A 50Ah can run a 12 volt fridge but depends on ambient temp and if you are opening that fridge a lot.

I run 2 similar12 volt fridge/freezers full time at my cabin. One is a fridge the other a freezer and the freezer unit runs considerably more often because it has to pull the temp down a lot farther.

I run one off a 10oAh AGM and 200 watts of solar but if I don't get good sunlight that system will struggle. The other I run off 400 watts and 200Ah and never an issue.

So it looks like we have to just be patient and wait for the extra batteries and panels to fit into the budget. I'm just so glad the Renogy controller has that built in jump start set up, after reading about all the trouble people have to get drained LifePo4 batteries going again.

 

[Rednecktek]

Another thing to consider is that the inverter itself has a little bit of draw just to be on and waiting. If your battery was only at 13v that's the very beginning of yhe curve and it takes a LOT of watts to go from 13.1v to 13.2v and more to go to 13.3v. If your controller is stopping at 13.8 your battery is only Mostly full. Add in the constant little bit of drain from the inverter waiting and ready to power your AC stuff and it sounds like you got jjjuuusssttt lower than everything could handle.

 

[Tamacat]

Another thing to consider is that the inverter itself has a little bit of draw just to be on and waiting. If your battery was only at 13v that's the very beginning of yhe curve and it takes a LOT of watts to go from 13.1v to 13.2v and more to go to 13.3v. If your controller is stopping at 13.8 your battery is only Mostly full. Add in the constant little bit of drain from the inverter waiting and ready to power your AC stuff and it sounds like you got jjjuuusssttt lower than everything could handle.

I'm leaving the solar off for tonight, with 12.8 on the battery at sundown. The inverter is off. We'll see what happens. I'm just glad as heck the solar control has that jump start feature. But, I have othe newb questions to ask! So on to that.

 

[Rednecktek]

Ask away!

 

[Tamacat]

Ask away!

See Toddler part Two. ?