# Vtc6m based battery, cell unbalace already while charging
**URL:** https://foil.zone/t/vtc6m-based-battery-cell-unbalace-already-while-charging/26866
**Category:** Build, Repair & Mod
**Created:** [July 23, 2026, 7:57pm UTC](https://foil.zone/t/vtc6m-based-battery-cell-unbalace-already-while-charging/26866 "2026-07-23T19:57:53Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@javierru](https://foil.zone/u/javierru)
#### Post date: [July 23, 2026, 7:57pm UTC](https://foil.zone/t/vtc6m-based-battery-cell-unbalace-already-while-charging/26866/1 "2026-07-23T19:57:53Z")
hi there,
I have built a third battery for my efoil/foil assist. the first two batteries were 12s2p reliance rs50 and I am very happy with their performance.
I wanted to build a third pack but I had problems to source the same cells for a reasonable price and since I do not need many cells, sourcing them directly from china is also quite expensive.
therefore I sourced vtc6m from nkon and built a 14s3p.
already at the first charging I got a cell imbalance of 0.038v while chargeing 5A, much bigger than anything I have seen with the RS50s, therefore I would appreciate some opinions on this matter. I use the cells from 4.15v to 3.4v so i think that a bank with a little less capacity should cope with my usage but I have no experience with such a problem.
What are your experinces with something like this?
Thanks in advance!
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### Author:  [@DutchFoiler](https://foil.zone/u/DutchFoiler)
#### Post date: [July 23, 2026, 8:57pm UTC](https://foil.zone/t/vtc6m-based-battery-cell-unbalace-already-while-charging/26866/2 "2026-07-23T20:57:03Z")
The issue is within group 7.
I’d measure by hand with a multimeter.
Could be a bad cell, pierced cell, bad connection, anything. Best to swap it out / fix it asap while the battery is still new. Like this the age difference will be minimal.