Fixing takuma efoil battery with low voltage

Hello everyone, this is a question about a friend’s efoil and not a personal build, any help would be greatly appreciated. So a friend has a takuma efoil that he bought about 3-4 years ago and currently the battery shows about 4 volts. When fully charged the voltage drops almost immediately so as you can imagine most of the individual batteries are toast. Is it worth it to try to fix it by measuring and replacing the dead cells? Or is there any chance i can find him a new pack and not a complete battery? New ones are apparently not easy to get and certainly not for a price that makes sense. I am attaching a couple pictures of the inside of the battery.


Battery is dead, no chance of reviving it without replacing all cells. I don’t know the takuma design so how difficult/integrated the pack is to change all the cells… it is likely that you need to clear some protection flags with their software. Let’s hope a Takuma owner can help you.

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@Simos2020 …i dont suppose you could take some photos of the charge port wiring loom. Im intwrestd to see what goes where.

Cheers
K

TLH-12s14P Wide open here. 1400usd + 200 shipping (+ tax ? ) seems a fair price…
https://www.aliexpress.us/item/3256804025203480.html

Model No. TLH-12S14P-44350
Dimmension 26525070(mm)
Voltage 44.4V
Capacity 35Ah
BMS Smart BMS with communication protocol (Available)
Discharge cutoff Voltage 33.6V
Charge cutoff Voltage 50.4V
Working current 100A+
Charge current 5A or 10A fast charger
Charging and charger CC/CV with professional charger
Weight 9.5Kg
Warranty 12 months
Cycle Life Over 500 Cycles

i will get some pictures later, there’s the 2 high voltage cables and a few communication wires for the esc

Thanks, i found a local shop that replaces cells and they quoted me around 850 euros to replace them all so i will explore that option first and we’ll see. The price is honestly more than fair, it’s almost cost price for the cells themselves.

Beware of the cell quality. What ref are they using ?
In EU, this 35AH long range battery cost 1930GBP/2600USD/2200EUR incl tax

they gave me a few options to use different ones, they told me i might as well use higher capacity cells and instead of 12s14p make a pack that is 12s but 10p or even 7p. I haven’t chosen yet since they will be closed for a couple weeks and i’ll send them the battery once they open again.

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