Resuscitating a Lift eFoil battery

After opening the case I noticed that testing the cells would be a non feasible job so I decided to try to bring it back to life as whole.

  • a bit of history:
    My battery is from the end of 2019, has less then 50 cycles.
    It was left without charging for about 2 years because I was out of the country during the pandemic.
    Upon my return there was no LEDs on
    The charger did not recognize the battery and began showing error 029

What I did was charge the battery “behind” the BMS with 13.8v at 3A for six hours, unplug the charger and wait for the cells to balance themselves (by checking the voltage drop on the voltmeter) and repeated that process until I’ve got a consistent ~13v reading.
Next I used a 24v 3.2A with the exact procedure as above.

Next I used a 42v 4A. The procedure was a bit different.


So, for the 42v procedure…
Initially the same as with other chargers, charge and repeat until voltage stops falling on the voltmeter.

Since there was still no LEDs I decided to remove the cables from the BMS and maybe reset it.

It didn’t work removing the connectors so…

This is very interesting, but I would not mess up with lithium ion batteries. If they are deeply discharged the cells can damage themselves and create a short cut over time.

You are right. But I am in Brazil, 100% impossible to receive a new battery by courier. My option were to give up and don’t foil until the opportunity to go to the USA and bring a new battery or to tweak it and see how it goes.
This is why I made the 4 steps on voltage to charge the pack, it was the safest way.
Now the battery is working with all the LEDs on and charging perfectly with the original charger.
It still is not turning the board on. The box does recognize the battery but it does not close the relay sending voltage to the terminals. It might be the 9v battery on the controller box too weak, it is what I will try tomorrow.

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You are living on the edge with this pack… Hope you store it outside…don`t wann burn your house down :smirk: