Faulty battery Advise Please

Hi, I ordered a 12s5p 30q battery in Nov 2020 from a company in Europe. It came down mid Feb 2021 But it will only charge to 63% … I have contacted them and they asked for it to sent back, but the shipping back is more than they want to pay. We are now at a stand still. Am i being unreasonable to expect a replacement as not my fault that is not working or that the postage is more expensive to go back. What would you do ?? Just after some advise please

Did you use it?

Yes the day it came down, I was so excited as the battery was the last thing to come for my first DIY( the battery was at 26% ) i set up the unity made sure everything worked had a short ride up and down the street then put battery on to charge but it stops at 63%.

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pics? would make life easier
also how did you measure the 63%? voltmeter?

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Name the seller and put some pics here. Best bet is to open it up (while communicating this with the seller) and see exactly what is wrong.

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Btw, a 12s pack should give you 50.4v fully charged. Make sure the charger can provide this voltage and then measure the battery’s voltage a few minutes after you take it off the charger. It’s possible that you set up the vesc as 13S and it’s showing an incorrect percentage

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What cutoff voltage did you set?

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The voltage is 45.9 when charged to 63% that is going by the indicator that came on it, so thinking a faulty bms,( it is set up as 12s ) the seller did say he could send a bms if i could swap it but out of my league doing that No soldering/battery experence.

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please use a multimeter to confirm its that voltage just to make sure

what bms? and what seller?

Had to borrow a friends phone to get unity app as i have a mac and could not get vesc tool to work , I do not remember voltage cutoff

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setting it too low can ruin your battery and the symptoms would be what you described in this post.

Up and down the street 500 meters and I don’t have the skills or tools to check voltage, would a regular electrician have the skills to fix / check it?

I think i just left the default cutoff on the app for 12s

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okay thats good. It may be a bad p-group

I dont have the skills or tools to check the P-groups or bms , would a regular electrician have the skills to do this ???

Yes, but they’d be pissed off once they find out what the job is. Do you own a voltmeter?

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No i dont

do you have a photo of the battery? Who did you buy it from?

Don’t want name them / throw them under the bus yet . just wanted to know what some else would do in this position not having the skills to check/fix it my self . Thanks for the help anyway

I dont have a multi meter , was just wanting to know what other people would do in this position if they did not have the skills to fix/check it them selves . Thanks anyway

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