16s only charges to 65%

[Boofheadeu]

Is it the charger and how do I check that? Is it bad cells ..what do I do for that.  ?? Have 4000 clicks on it.  I am stuck in cuba..there are many electric moter cycle here. Could I take my battery out and take it to one to replace dead cells?  

[Tawpie]

Checking the charger just requires a multimeter, see if it's outputting the correct voltage WITHOUT shorting anything together.

As to getting someone to diagnose the battery pack and fix it if needed, look for a highly skilled person! These things generally don't take kindly to getting connections wrong, or low quality cells, or cheapo nickel strips or sloppy work with the spot welder. But given the large number of electric motor cycles there probably are people there that can take care of you! If your charger is ok and you can't get a genuine replacement battery, what do you have to lose?

***emphasis on "highly skilled", a repaired battery pack that catches on fire is not something you want.***

[mrelwood]

Only charging to 65% is quite a clear indicator of dead cell groups in at least one of the battery packs. The first ones died on my 16S at exactly 4000km as well.

65% battery = 61.32V. One dead group and others perfectly at 4.2V would be 63.0V (= 75%), so you probably have a second group on its way out as well. Or the rest are just badly out of balance.

 Be very careful when accelerating or braking with that wheel!!! It doesn’t have anywhere near the power it does with healthy batteries, so you can overlean the wheel much easier.

 If a local shop does Li-ion battery repairs, you could ask if they’d work with your battery as well.

 Whether you’ll have the faulty pack repaired or not, I would disconnect the faulty one. Charging a dead cell group has a greatly increased risk of violent battery fire. Running with only one healthy pack should also give you a better range and better power.

 

 Disconnect one battery pack, and try to charge the wheel. If it now charges beyond 65%, you have successfully unplugged the faulty pack. Tape the connector of the faulty pack shut and DO NOT RECONNECT THE FAULTY BATTERY EVER AGAIN!!! The packs are now at a different voltage, and trying to have both packs connected would at minimum melt the connectors and burn your fingers, or worst case the huge inrush current could ignite either the shorted cells, or the ones that are already at the maximum charge.

 If the wheel didn’t charge any further, first unplug the remaining faulty battery, tape its connector shut and NEVER CONNECT THAT BATTERY PACK AGAIN! You can then reconnect only the pack you disconnected first. The wheel should then charge further.

If it still doesn’t get up to 100%, the other pack is probably faulty as well.

 If you do get the faulty pack repaired, you absolutely do need a multimeter before you can connect both packs! The packs MUST be at the exact same voltage (+- 0.1V) before connecting. Charge up the pack with a lower voltage until the packs are at the exact same voltage.

 Do not check the voltage from the app, you MUST measure both packs with the same measurement device!