Charging a 12s battery can you do this?

Jonisingt35r

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Jul 18, 2019
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Hello
I have a 12s battery, I've got a 6s charger can I charge 1 to 6, then 7 to 12?
Thank you
 

Bubba

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May 9, 2018
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Are thinking of bypassing the BMS?
Does your charger have managment to stop charging when the cells are full?
 

daromer

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If thats an 6s rc charger then yes it works great doing that.Just build custom 6s balance leads and wires doing so. Its rather common when doing rc when you talk about high power that you use multiple battereis in series. And they are kind of charged like you say.

Do note that you need to custom build the contacts unless they exist!
 

Jonisingt35r

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Jul 18, 2019
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Yes it's a Rc charger, pretty sure the charger stops at 4.2 think you can adjust it hope to stop at 4.1v.
No bms I live life on the edge, :) will get another one when I get round to

Hi daromernot sure what you mean about the contracts? Thanks
 
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Ebikeforlife

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Jan 6, 2021
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I used to do this with 6s RC Charger... It is a Pain in the Arse to do but yes it can.... I advise adding the balance leads though so that the RC Charger will Balance up the cells....

The other option i use is a MingHe BST 900w and a computer power supply, i have even done this with a 42V 5A ebike charger connected to it
 

Jonisingt35r

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Jul 18, 2019
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hello ebike, not sure what you mean, by just using a power supply? i thought you had to charge a 12s battery using balance leads so each cell has a chartering circuit? are you saying you can charge as 12s batt connecting just 50.4v across it?
thank you
 

Ebikeforlife

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Jan 6, 2021
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Yes you can but I don't recomend doing that unless you are closely monitoring each cell string voltage so that none go above 4.21v

If the pack is out of balance it will just keep charging till it hits the 50.4 volts

This can mean that an out of balance pack can push some cells above the rated voltages causing a fire hazard....

But saying that, I am just sat diagnosing a faulty ebike battery that has gone below cutoff voltage by individually charging each cell string to 3.7v storage voltage and let them sit with BMS disconnected to see if there are any self discharging cells... This pack has been sat for months and was switched on when it arrived so it could just be the residual power used by the BMS that has taken it low...
 

Jonisingt35r

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Jul 18, 2019
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opps
 

Jonisingt35r

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Jul 18, 2019
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was pretty sure you could do it just wanted to be sure didnt think about going overvoltage on a cell i do have a 12s charger
thanks
 
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