Sleeping battery

[Sniper45]

Hi I bought a gepida reptila 900 with a battery that has not been charged so isn't getting recognised by the charger is it possible to restart this battery if so how do I do it

 

[cyclebuddy]

Neal's already answered your question on your previous thread here.

If the long-press button trick doesn't work, you'll need to open the battery and try charging individual cells/cell strings... that's only possible if it's unbalanced or if it's slightly below LVC. If it's been left for dead for a considerable time, you'll need to recell or buy a new one.

The first thing to do is measure the battery voltage at the output terminals with a multi-meter.

 

[Nealh]

If the battery is using handshaking then it may not be possible to get a voltage reading, if so one is back to my original advice of manually carrying out the work to see if it is recoverable.

 

[Nealh]

Any one with a bit of common sense and able to carry out repairing stuff can and is able to carry out voltage measurements if they have a meter. Once the battery case is open we can give guidance to proceed, no mechanical deconstruction of the battery is required. It is best to show pics of what is in front of one to proceed so we can see what you have.

 

[Andy-Mat]

Hi I bought a gepida reptila 900 with a battery that has not been charged so isn't getting recognised by the charger is it possible to restart this battery if so how do I do it

I have no idea what nominal voltage your battery is, but if it is 36 v, then the Stark company sell a 36 volt battery charger, that is also called "A Zero Volt Charger", to recover sleeping batteries.
I had to use it myself after my Stark bike was so long in delivery, the battery would not charge from the normal charger. It only took a few minutes to get the battery charged enough to allow the normal charger to work, but the 0 volt charger does both jobs.
Here is the link, but remember, the connector may need to be changed for your charging socket, observing polarity correctly of course:-

Home :: Accessories :: 0V Recovery Charger

Use this to recover your battery if it has not been used or charged over a long duration of time you only need to use this charger one time and then a normal charger can be used The 0V charger will only recover a battery with voltage from 22V to 27V cut off voltage You should measure the voltage...

starkdrive.bike

Its cheaper than a new battery....
regards
Andy

 

[Nealh]

27v is often still not high enough voltage for a lot of BMS to recognise so may still not charge. Most branded cells have a min 2.8v discharge and a hell of a lot of BMS will want to see at least 3.0v or more. 27v for 10s is only 2.7v.

 

[matthewslack]

I have a sleeping old shimano 6100 I think battery that came very cheaply. When I opened it up, it was perfectly clean, and cell balance was within 2mV, but 10S measured a total of 12.5V!

When I get round to it I shall carefully charge using a small solar panel setup and check at various intervals of voltage whether the charger will work.

 

[Nealh]

Tbh any cell under 2v can't be trusted 1.25v average means it really is only suitable for the recycling bin or the cells might be used as torch batteries.