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Discussion Starter · #1 ·
Gen 1 Chevy Volt Battery reconfigured to 2x 144v sets. Need help with adjusting used NG3 Lithium charger to charge these.

A long time back I obtained these batteries and while standing quite a while they still measure out ok. I have recently been given a used NG3 Zivan charger that was formerly used to charge 144v of thundersky type batteries I think.

Will I only need to adjust the voltage pot inside? Will the other sittings be "ok" as is? Could someone more experienced charging these batteries and knows a bit about the NG3 please help me?
 

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Chevy Volt is NMC, Thundersky is likely LFP. I can't seem to find any docs on NG3 charger suggesting any user configuration. Here is one for example :

Even if you can adjust the voltage output on the charger, you need to ensure individual cells don't fall out of balance and get sent over their maximum voltage. In other words you want a BMS that has ability to disconnect the charger in case of cell overvoltage condition.
 

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Discussion Starter · #4 ·
Chevy Volt is NMC, Thundersky is likely LFP. I can't seem to find any docs on NG3 charger suggesting any user configuration. Here is one for example :

Even if you can adjust the voltage output on the charger, you need to ensure individual cells don't fall out of balance and get sent over their maximum voltage. In other words you want a BMS that has ability to disconnect the charger in case of cell overvoltage condition.

a BMS is over a thousand dollars US and then you do the currency conversion to NZ dollars. I will be trying without BMS and monitoring the cells manually. At least at first. It has been done before successfully. running the batteries too low is what puts them out of sync. I have two duplicate packs of 144v. cross connecting the cells will provide a limited self balance as well.
 

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Discussion Starter · #5 ·
What i was really hoping was someone who knows these cells and could suggest a output voltage to set the NG3 to. I could try as is and monitor it closely . WHich may be the case if no one has any ideas
 

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What i was really hoping was someone who knows these cells and could suggest a output voltage to set the NG3 to. I could try as is and monitor it closely . WHich may be the case if no one has any ideas
4.2v is the max for all NMC cells. Ideally you should not charge to the max, so 4.1-4.15 at most.
 

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Discussion Starter · #10 ·
I am looking for the output voltage total from the charger. They charge at a higher voltage than the pack and then ease it back when the pack is at 144. This charger was charging 144v before but with batteries a bit different. I know what the max per Chevy Gen 1 cell is . Im looking for what might be a good output voltage to set this charger to.
 

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Discussion Starter · #11 ·
You're totally right! I should be nicer to people, support and encourage unsafe design and operation of high power systems.
I dont think its unsafe if its monitored and tested. We have strict rules here but nothing says a BMS is compulsory. I simply cant afford one. And I dont own a house either. My aims are to test these things. I dont agree with you and would rather you commented somewhere else
 

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I am looking for the output voltage total from the charger. They charge at a higher voltage than the pack and then ease it back when the pack is at 144. This charger was charging 144v before but with batteries a bit different. I know what the max per Chevy Gen 1 cell is . Im looking for what might be a good output voltage to set this charger to.
You need to know the S-count. 144V is a nominal label that does not tell us anything specific.

If 39S them 4.15V is 161.85V 162V close enough termination voltage

If 40S then it's 166V
 

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Going without a BMS is fine

but greater knowledge is needed.

And the gear to properly monitor per cell-group voltages, and to balance your groups manually.

You need to monitor your cell-group voltages when charging most especially so you stop before the first one hits 4.20V

While driving, before approaching 3.2-3.4Voc even higher really best for longevity.
 

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I am looking for the output voltage total from the charger. They charge at a higher voltage than the pack and then ease it back when the pack is at 144.
You clearly don't understand basic electrical concepts - there isn't a pack voltage that you can monitor which is different from what the charger is applying to it, unless you have some substantial resistance in your wiring causing a meaningful voltage drop.

I know what the max per Chevy Gen 1 cell is . Im looking for what might be a good output voltage to set this charger to.
Without a BMS, you will know the total of all of the cell voltages in series, but how will you know the voltage of each cell... or more importantly, the most-charged cell?
 

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You need to know the S-count. 144V is a nominal label that does not tell us anything specific.

If 39S them 4.15V is 161.85V 162V close enough termination voltage

If 40S then it's 166V
That all makes sense, but 144 volts isn't even the nominal voltage of the proposed pack. A battery assembled from first-generation Volt modules must be a multiple of 6S (unless the modules are reconfigured by cutting and reworking cell tab connections within the module). He likely thinks that 6S3P and 12S3P modules have nominal voltages of 24 and 48 volts (because they are sold that way), so his "144 V" string is likely 36S3P. GM thinks that a 96S set is nominally 360 V (3.75 V/cell) - and 395 V fully charged (4.11 V/cell) if it matches the second-generation cell characteristics - so 36S is 135 volts nominally (and likely 148 V fully charged if perfectly balanced)... but what would they know? ;)

The amusing thing is that sometimes two wrongs make a right: the wrong voltage description by incompetent vendors (48 V for 12S instead of 45 V) happens to be close to the fully-charged voltage (48 V for 12S or 144 V for 36S).
 
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