LIFEPO4 Battery discussion thread

Just a question.

My 5kW omnivolt, when it hits 100%, cuts the charge immediately. Then every hour I see the battery dropping some 1% or so even in passthrough mode, which is probably just the inverter losses (50 to 60W).

Is this considered normal for LFP-supplied inverters? I see you guys talking about absorption time, etc. I assume this is just for balancing Cavedog's battery? LFP doesn't need that when it's healthy?

I have checked mine even when it just hits 100%, and the worst I have seen is a 0.001V deviation, and some days it's no deviation at all.
 
denmendez65 said:
Just a question.

My 5kW omnivolt, when it hits 100%, cuts the charge immediately. Then every hour I see the battery dropping some 1% or so even in passthrough mode, which is probably just the inverter losses (50 to 60W).

Is this considered normal for LFP-supplied inverters? I see you guys talking about absorption time, etc. I assume this is just for balancing Cavedog's battery? LFP doesn't need that when it's healthy?

I have checked mine even when it just hits 100%, and the worst I have seen is a 0.001V deviation, and some days it's no deviation at all.
Click to expand...
Some of the newer bms cuts the charge mosfets at 100%. So even if you do keep voltage on the battery it will not accept a charge till it lost like 5% of its SOC.

The omnivolt inverter probably has coms to the battery inside? It will tell the inverter to stop charging and then slowly drain the battery till like 95% and start charging again. Some bms will issue charge and 98%. When running coms with the inverter the inverter will only apply a voltage to battery when the bms says it needs a charge
 
denmendez65 said:
Just a question.

My 5kW omnivolt, when it hits 100%, cuts the charge immediately. Then every hour I see the battery dropping some 1% or so even in passthrough mode, which is probably just the inverter losses (50 to 60W).

Is this considered normal for LFP-supplied inverters? I see you guys talking about absorption time, etc. I assume this is just for balancing Cavedog's battery? LFP doesn't need that when it's healthy?

I have checked mine even when it just hits 100%, and the worst I have seen is a 0.001V deviation, and some days it's no deviation at all.
Click to expand...
Absorption time on LFP is affected by voltage. Higher voltage shorter absorption. 14.6V needs no absorption. 13.8V would need about an hour.

Also the cutting off is some bmses do that.
 
wingnut771 said:
Absorption time on LFP is affected by voltage. Higher voltage shorter absorption. 14.6V needs no absorption. 13.8V would need about an hour.
Click to expand...
So its not a time you set? Nothing I need to concern myself with then. Hits the knee point and then BMS cuts off?
 
denmendez65 said:
So its not a time you set? Nothing I need to concern myself with then. Hits the knee point and then BMS cuts off?
Click to expand...
omni volt battery have coms port? mind sharing them (photo)?
 
DTBA said:
On most bms its about amps. It will keep the voltage at say 55.2 volts and then if the current drops below 2amps and it calls it 100%SOC reset
Click to expand...
and the really crap bmses call 100%SOC when cell hits 3.65V OVP.
 
denmendez65 said:
So its not a time you set? Nothing I need to concern myself with then. Hits the knee point and then BMS cuts off?
Click to expand...
Nothing to concern yourself with really.

When you charging at 55.2V and it hits 55.2V and charging stops hypothetically (a cloud), you will see resting voltage will drop off straight away to like 52.8V because it hasn't had time to absorb, therefore its not really 100%. If it has been absorbed then voltage wont drop as much to something like 53.6. If you charged to 58.4V and a cloud comes past then it will also drop to 53.6V but without needing absorb time, ie; it charges faster.

I hate using percentages with LFP. When you say there is 0.001V deviation at 100%, what voltage is that? Check deviation at 58.4V.
 
I'm worried about my 2nd hand battery but look at the new ecco battery. The balance is also terrible.

Screenshot 2026-05-22 160932.png
 
DTBA said:
When does battery 1 go to 100%soc? is battery 2 your new ecco battery
Click to expand...

I'm not sure because it hits ovp on one or more cell before. How can I reset the SOC to 100% on it in the app? is it possible?

Battery 2 is the new ecco battery.
 
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