36V LifePO4 battery charge voltage & maintenance

[Ggtronic]

hello

 I own a 36v12ah battery pack since 2 years :
http://www.goldenmotor.ca/products/36V12AH-LiFePO4-Aluminum-Cased-Battery.html

at the begining... the charge top off voltage was 42.5 volts...

recetly, I saw my bike indicating 44 volts and i'm concern about OVER voltage !

my charger output 44volts in standby mode no output...

question :
--what voltage should my battery reach ?
--What device control top off voltage : battery BMS or the charger ?
--What would be the best "storage voltage" ?

thanks for any clue...

meanwhile I don't let the battery top off and stop it myself when 40v or more

[Bikemad]

My 16 cell 48V LiFePO₄ battery cuts off at 58.4V (3.65V/cell).
So, if your 36V battery has 12 LiFePO₄ cells, I would expect it to cut off at 43.8V (3.65V per cell) or 43.2V (3.6V/cell) for some of the newer batteries.

The maximum charging voltage is governed by the charger output voltage which is usually stated on the charger.

If the battery doesn't reach the correct maximum charging voltage, then the BMS will not be able to balance the cells correctly (which usually takes place at the end of each full charge).

The general guide for long term storage is ~50% of the battery's capacity, which is not easy to determine with a voltmeter due to the flat discharge curve of the LoFePO₄ batteries.

It is probably best to fully charge the pack and then use the bike to run the battery down to approximately 50% capacity (this is easy to do if you have a wattmeter or Cycle Analyst etc. to measure the used Ahs).

Ideally, the battery should also receive a top up charge every couple of months to prevent the voltage from falling too low due to self discharge of the cells and/or the continuous low current BMS drain.

Alan