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Batteries randomly dumping Amps

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Wallytrogg

New Member
Joined
Apr 3, 2024
Messages
15
Location
Baffle creek
Hi everyone, newbie, I've got 400amps lithium, 40amp DC/DC and 1200w solar through a 60amp controller.
Randomly, 3rd time in 2months, I'll wake up in the morning and what was 200-300amps will be gone, batteries have shut down and monitor reads 0 percent.
I have the DC/DC isolated and only turn it on when I drive.
So I wait for the sun and start the van for DC/DC wake the batteries up and all charging smoothly except from 1% when the batteries wake up.
Removed dc/dc ...still the same

Only running 2 fridges at about 6 Amps tops.
Any ideas about what's happening..or where it disappears to?
Cheers Wally
 
What are you using to gauge the state of charge? If anything other than a shunt, it's probably not accurate. If you're using a shunt, your settings may not be correct.
 
You should probably start by using the right units... amps is current flow. Batteries are amp hours, which is meaningless without giving the voltage, which you didn't. Stored energy is Watt-hrs, or amp hours if you state the voltage.

Agree, Need to know how you are estimating 200 to 300 amp hours of power gone, what kind of battery monitor or shunt. If accurate, some sort of short. Do you use negatives to flow all loads back to battery? If not and you use chassis... good luck tracking it.
 
JeromeS13 said:
What are you using to gauge the state of charge? If anything other than a shunt, it's probably not accurate. If you're using a shunt, your settings may not be correct.
Click to expand...
Using Eco worthy with the donut.. all going in and out runs through..2 yrs always spot on..
 
Dave in AZ said:
You should probably start by using the right units... amps is current flow. Batteries are amp hours, which is meaningless without giving the voltage, which you didn't. Stored energy is Watt-hrs, or amp hours if you state the voltage.

Agree, Need to know how you are estimating 200 to 300 amp hours of power gone, what kind of battery monitor or shunt. If accurate, some sort of short. Do you use negatives to flow all loads back to battery? If not and you use chassis... good luck tracking it.
Click to expand...
Cheers and sorry for the wrong terminalogy.. voltage is always 12.8. and amp/hrs and what/hrs are on the Eco worthy donut.
It reads everything in/out. Was 200 Amps in batteries @ 12.8v..then 0.. and batteries shut off completely.
All earth's to batteries.. except the DC/DC which I eliminated by removing.
 
Wallytrogg said:
Cheers and sorry for the wrong terminalogy.. voltage is always 12.8. and amp/hrs and what/hrs are on the Eco worthy donut.
It reads everything in/out. Was 200 Amps in batteries @ 12.8v..then 0.. and batteries shut off completely.
All earth's to batteries.. except the DC/DC which I eliminated by removing.
Click to expand...
Thx. No worries, but like to be on same page before troubleshooting ;) That's a tough one, little opportunity for a drain going on there. I'm stumped.
 
Wallytrogg said:
Cheers and sorry for the wrong terminalogy.. voltage is always 12.8. and amp/hrs and what/hrs are on the Eco worthy donut.
It reads everything in/out. Was 200 Amps in batteries @ 12.8v..then 0.. and batteries shut off completely.
All earth's to batteries.. except the DC/DC which I eliminated by removing.
Click to expand...

12.8V is an extremely low state of charge.

You should be charging your batteries to at least 13.8V and preferably 14.2V+
 
To add.. when Eco worthy reads 50% of 400 amp capacity..2x200 in parallel...C agrees.. about 200,000 mAh ..E is about 2000 Wh.... Then the bang..0 everything.wait till solar charges to 1% then everything charges normal until about a month or 50% then bang again...
 
Hmmm me too..no fuses blow.. BMS must allow it to happen due to parallel batteries allow my 3kw inverter or my 3kw infrared cooktop to run at full power..
So maybe BMS is dumping and then shutting down when the batteries are depleted.
Dave in AZ said:
Thx. No worries, but like to be on same page before troubleshooting ;) That's a tough one, little opportunity for a drain going on there. I'm stumped.
Click to expand...
 
Dodgy BMW's..both or just one... batteries are only about 6 months old... replacing 2x100 which ran perfectly with the same setup.. so did the 2x200 until about 2 months ago..then this?
 
Wallytrogg said:
Eco worthy donut.
Click to expand...
Guess I don’t understand, what’s that?

Yes, sounds like the BMS is shutting the batteries down when they are depleted, and your capacity guage is drifting between events. You need to allow it to reset in the fully charged state more often to avoid it resetting in the fully depleted state.
 
Wallytrogg said:
Sorry 12.8v is v coming out...yes always charges at lithium setting... currently 14.2v
Click to expand...

That's my point. An LFP battery reading 12.8V is at a low state of charge - 20% tops regardless of what the battery monitor says.

I would assume also that the battery monitor would read 0% following a power loss no matter what it read before BMS cut off.

You may have a 1200W array, but you're only able to charge at 60A * 14.2V = 852W MAX.

Are these fridges 6A @ 12V?

Do you have an inverter?
 
wpns said:
Guess I don’t understand, what’s that?

Yes, sounds like the BMS is shutting the batteries down when they are depleted, and your capacity guage is drifting between events. You need to allow it to reset in the fully charged state more often to avoid it resetting in the fully depleted state.
Click to expand...
Well ok... but even if the gauge is out.. it only reads.. Eco worthy has to commence recording in/out from 0 charge to be accurate..
 
sunshine_eggo said:
That's my point. An LFP battery reading 12.8V is at a low state of charge - 20% tops regardless of what the battery monitor says.

I would assume also that the battery monitor would read 0% following a power loss no matter what it read before BMS cut off.

You may have a 1200W array, but you're only able to charge at 60A * 14.2V = 852W MAX.

Are these fridges 6A @ 12V?

Do you have an inverter?
Click to expand...
Hmm .. it's hard to remember the numbers when everything is going well... I remember fully charging the batteries on 240v lithium charger don't remember the v when fully charged. Do remember checking at inverter under load and reading 12.8 at the inverter terminals.
Hense the slow climb to 50% as to solar. Topped with DC/DC .. regardless... doesn't explain loosing 50% capacity in the blink of the eye...
 
sunshine_eggo said:
That's my point. An LFP battery reading 12.8V is at a low state of charge - 20% tops regardless of what the battery monitor says.

I would assume also that the battery monitor would read 0% following a power loss no matter what it read before BMS cut off.

You may have a 1200W array, but you're only able to charge at 60A * 14.2V = 852W MAX.

Are these fridges 6A @ 12V?

Do you have an inverter?
Click to expand...
Yeah fridges are about 3amp draw each...3kw inverter... never use it..
 
Wallytrogg said:
Yeah fridges are about 3amp draw each...3kw inverter... never use it..
Click to expand...
Should the batteries read 14.2v regardless of whether the capacity is 1% or 100% ??
It seems like the batteries won't restart until the Amps reach 1% and the voltage reaches 12.8v...anyway
 
wpns said:
Gotta ask again, what is that?
Click to expand...

I'm guessing there's a hall effect sensor for the battery monitor.


Wallytrogg said:
Hmm .. it's hard to remember the numbers when everything is going well... I remember fully charging the batteries on 240v lithium charger don't remember the v when fully charged. Do remember checking at inverter under load and reading 12.8 at the inverter terminals.
Hense the slow climb to 50% as to solar. Topped with DC/DC .. regardless... doesn't explain loosing 50% capacity in the blink of the eye...
Click to expand...

You're assuming the 50% is accurate. Current counters regularly need to be re-synced typically at 100% at least a few times a month to remain accurate.

Wallytrogg said:
Yeah fridges are about 3amp draw each...3kw inverter... never use it..
Click to expand...

understood. And it remains off all the time?

Wallytrogg said:
Should the batteries read 14.2v regardless of whether the capacity is 1% or 100% ??
It seems like the batteries won't restart until the Amps reach 1% and the voltage reaches 12.8v...anyway
Click to expand...

No. You should attain 14.2V for about 30 minutes to ensure the batteries are fully charged.

Let me state it this way...

If you ever see your battery drop below 13.0V while under a measly 6A load, you are under 30% SoC regardless of what the battery monitor reports. 12.8V - about 20%.

Given your small loads and big array, it's mind-boggling that you would ever observe anything below 13.2V unless it's overcast all the time.

Given your extremely low C rate, you 1) have an excessive load drawn from the battery that you don't know about, 2) you use more energy than you think you do, 3) you are not getting good PV charging.

The idea that you're "dumping" lots of current in a very short period of time is highly unlikely. A failure of that nature would likely render the batteries non-functional.
 
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