Battery SOC minimum %

wingnut771 said:
Apparently the Deye inverter has a battery initialise mode or whatever that is supposed to wake up a dead battery, but I've never seen a youtuber having to wake one up before. Plenty of 12v examples but thats not what we're talking about here.
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Yea some sort of emergency or battery wake up feature is at the front of my list
 
wingnut771 said:
So it didnt go flat, the BMS failed doing its job randomly?

How was the warranty process?

Stories like this reafirm my strategy of buying cells and bms and assemble it myself. I have no fear of electricity, but I know of a few peeps that have it, like spiders and thunder, but thats their problem.
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I suspect it went flat or had an issue and the inverter went into bypass mode, maybe with the break in loadshedding at the time the guy did not realise it wasn't cycling the battery, he did say he wasn't too familiar with the system so he did not fiddle much with the system.

The supplier dealt with the issue, so I am not sure if it was handled on the basis of his relationship with his supplier/ manufacturer or if it was a genuine warranty claim.
 
wingnut771 said:
but takes 9 days to arrive from geewizz.

Anyway, this topic is moot as I refuse to believe a 16S bms will shut down at 39.9V.
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Yea that is why you hotta biybit before hand

Yea also thought so as the voltage lifts quite a bit when load dissapears

So as long as the auto switch on feature is off then it should switch off recover enough that if you switch it on it should fire back up

But yea i had the auto on enabled

Sonit chowed that buffer
 
leon.davibe said:
Yea butnif you arent awake or home

It switches off revivers auto starts
Eat a but more capacity
Switch off auto recovees

Rinse repeat
And eventually even with load gone it can't reviver enough to hit recovery voltage

Precisly why i had to jump/emergency

Showed the kid of this **** happens again do manual switch off

Training wasn't good enough still happened once after that
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Yes it might go to sleep but it should wake up when you press the button.

If it doesn't then I will morgage my house to pay for a front page ad in the newspaper shaming which ever brand ****ed me over.

I will become more famous than that bondi beach millionaire. I see myself getting a R3m check (not au$, I'm not greedy) from the cosmos just for highlighting (with much fanfare and hand gesturing) a stupid issue that should never happen
 
leon.davibe said:
Yea some sort of emergency or battery wake up feature is at the front of my list
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The way I compute it in my head is the BMS is an (up to) 16S, so it can be a 4S if you want? Not so?

So for the 16S BMS to got to sleep and lose power and never wake up again because there of 6V will never happen with 16s, but a good chance to happen with 4s but thats not a problem because everyone has a 12v lying around.
 
TheChamp said:
I suspect it went flat or had an issue and the inverter went into bypass mode, maybe with the break in loadshedding at the time the guy did not realise it wasn't cycling the battery, he did say he wasn't too familiar with the system so he did not fiddle much with the system.

The supplier dealt with the issue, so I am not sure if it was handled on the basis of his relationship with his supplier/ manufacturer or if it was a genuine warranty claim.
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What was the pack voltage when you had a go? Remember folks, this is 15S.
 
TheChamp said:
I don't think I had the parallel battery long enough to take readings, on its own it was just as dead as a Dodo.
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0V?

I remember you saying you had another one and will try jump it but apparently it was far away or something on the farm or whatever and then we never got an update.
 
wingnut771 said:
The way I compute it in my head is the BMS is an (up to) 16S, so it can be a 4S if you want? Not so?

So for the 16S BMS to got to sleep and lose power and never wake up again because there of 6V will never happen with 16s, but a good chance to happen with 4s but thats not a problem because everyone has a 12v lying around.
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Lithium batteries below a threshold voltage can easily be damaged and trying to charge them once permanently damaged can cause a dead short. So most bms's will disconnect a cell at a certain voltage to try and protect it and refuse to charge any cells below the set cutoff voltage.

If your battery shuts down due to low voltage but doesn't recover and continues to deplete its cells it can cause some issues.
 
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B-1 said:
Lithium batteries below a threshold voltage can easily be damaged and trying to charge them once permanently damaged can cause a dead short. So most bms's will disconnect a cell at a certain voltage to try and protect it and refuse to charge any cells below the set cutoff voltage.

If your battery shuts down due to low voltage but doesn't recover and continues to deplete its cells it can cause some issues.
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I'm talking about a flat 48V LFP BMS (hypothetically) going to sleep and wont wake up (reasons) when you press the button.

Can you use a 16S JK BMS on a 12V 4S setup?
 
wingnut771 said:
I'm talking about a flat 48V LFP BMS (hypothetically) going to sleep and wont wake up (reasons) when you press the button.

Can you use a 16S JK BMS on a 12V 4S setup?
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It depends on the specs. I would need to go look but many of them can do lower cell counts than their max. 16s to 4s might be a bit big.

Edit: looks like most will do 7-16 only so wont work for 4s setups.
 
wingnut771 said:
0V?

I remember you saying you had another one and will try jump it but apparently it was far away or something on the farm or whatever and then we never got an update.
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Yes, I had the 48V made up of gate motor batteries, I was so confident in my plan, the battery did turn on when I paralleled it with my Jumpstart ing battery, the idea was that as soon as the inverter sees some workable voltage it will take over, but as soon as I removed the external battery, the Pylontech would just switch off again, I did provide an update, the post I quoted is from that thread.
 
B-1 said:
Lithium batteries below a threshold voltage can easily be damaged and trying to charge them once permanently damaged can cause a dead short. So most bms's will disconnect a cell at a certain voltage to try and protect it and refuse to charge any cells below the set cutoff voltage.

If your battery shuts down due to low voltage but doesn't recover and continues to deplete its cells it can cause some issues.
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In theory your LFP should be fine (lab tests confirm this) if it doesnt go below 2.5V cell voltage and no charging below 0c temp which BMS should manage automagically. If you go to 2.5V, then you should get 6000 cycles to 80% SOH.
 
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B-1 said:
Lithium batteries below a threshold voltage can easily be damaged and trying to charge them once permanently damaged can cause a dead short. So most bms's will disconnect a cell at a certain voltage to try and protect it and refuse to charge any cells below the set cutoff voltage.

If your battery shuts down due to low voltage but doesn't recover and continues to deplete its cells it can cause some issues.
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The spec sheet says to not go below 2V cell volateg.
 
Batteries seem to all be topped up and sitting at 53.3v.

Screenshot_20251220_154031_Chrome.jpg

Cell voltage is sitting at 3.55v across all 6 batteries.

Screenshot_20251220_154106_Chrome.jpg

Screenshot_20251220_154130_Chrome.jpg
 
B-1 said:
Lithium batteries below a threshold voltage can easily be damaged and trying to charge them once permanently damaged can cause a dead short. So most bms's will disconnect a cell at a certain voltage to try and protect it and refuse to charge any cells below the set cutoff voltage.

If your battery shuts down due to low voltage but doesn't recover and continues to deplete its cells it can cause some issues.
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Sorry, I just only read your post porperly now, and want to set ypour mind at ease thast according to factory spec sheet for lfp cell states min v of 2V cell voltage. With this knowledge in hand, using 2.5V should give you comfort.

Regarding your BMS can disconnect a cell comment is - no offence - but is impossible with series connections. The only thing a BMS does is watch low V curt ogfg, high cuttoff, temp and over current (amps). Thats it, and the best part is that even though you use lead acid no comms settings, bms still does its thing, only diff is you live in voltage land instead of estimated % SOC land(may void commie warranty?).
 
wingnut771 said:
Just to clarify? What balancer does Pace have?
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Passive and balancing current 200mA on mine.

I open up my batteries once a year, usually after winter and balance the cells using my bench DC power supply. Charging cell 7 here, normally up to 3.55v, then move to the next.

Waiting for the passive balancer is just a waste of time.
 

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Koosvanwyk said:
Passive and balancing current 200mA on mine.

I open up my batteries once a year, usually after winter and balance the cells using my bench DC power supply. Charging cell 7 here, normally up to 3.55v, then move to the next.

Waiting for the passive balancer is just a waste of time.
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JK 1/2A active balancer FTW!
 
wingnut771 said:
JK 1/2A active balancer FTW!
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Don't think you can compare then, JK focus is on the DIY market and cater for self made packs where PACE is commercially focused.

You can do a lot of damage with an active balancer if you dont know what you are doing.
 
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