Renogy Battery not giving many amps

[Littleblackflash]

I stupidly let my renogy 100Ah battery go flat but I was able to charge it back to 100% using battery charger. The solar is now sufficient to keep the battery charged, which is only running the fridge. Day to day everything seams to be working fine (lights, heater, fridge etc)

I have a 1000W inverter attached. I can boil a kettle which is 700W perfectly fine, but my 900W air fryer isn't working. The inverter beeps at me now. I used to be able to run it and all other loads have been removed.

I can run the same inverter and the air fryer using a different battery. So I assume the Renogy battery can no longer supply enough amps.

Could it still be in a safe mode and somehow reset or is it broken and need replacing?

 

[Dellmassive]

they internal cells may be un-balanced,

you will need to fully discharge and fully recharge a few times to try an rebalance.

leaving it on charge for a couple of days can help Top-Balance it.

i take it its a Renogy battery with NO BT?

 

[Littleblackflash]

It has BT app connected. All 4 cells are currently 3.3V.

I was camping at the weekend so I've run it down to 25% each day before the solar topped it up to 80%. I did this 4 times.

 

[Littleblackflash]

I should add I've tried other 900w loads. A small microwave and an 800W kettle. With both of them the inverter cuts out and beeps, which is a sign of low battery. I guess it could be voltage or current. Cable lengths are short and oversized so current drop will be minimal.

 

[Dellmassive]

you need to run it down to 0% - until it shuts off.

and you need to charge to 100% - until its taking less than 1A from the charger.

running it 20-80% will unbalance the cells fairly quickly.

do the 24hrs at 100% charge to top balance it first.

if its still dropping power, then do the 100-0% cycle three or four times.

 

[Dellmassive]

I should add I've tried other 900w loads. A small microwave and an 800W kettle. With both of them the inverter cuts out and beeps, which is a sign of low battery. I guess it could be voltage or current. Cable lengths are short and oversized so current drop will be minimal.

keep the app open when your running your 900W load - and take multiple screenshots.

im expecting one of the cells voltage to plumet, which will trigger the problem.

you need to fully charge to 100% all the time - not 80% - as this causes unballanced cells.

 

[Littleblackflash]

Thanks for your help, I'll give it a go.

I normally charge to 100% but when we were camping we didn't get enough sunlight to reach 100% each day.