Charger Voltage

[Benjahmin]

I have two chargers, both with 3 pin xlr charge plugs.
One is a substantial metal cased 4A one (supplied with eezi kit) that has a good fan.
The other is a YZPOWER 2A charger with mini fan.
Both measure 41.7v output.
I thought it might be my meter but my wifes charger (supplied with Big Bear) measures 42v. Also confirmed by second meter.
My batteries measure 41.6-7v when hot off the charger.
I'm starting to wonder if my batteries are balancing at this lower voltages and if I should adjust the chargers to 42v?

 

[Benjahmin]

Anyone got any advice on this?
I don't want to adjust the voltage up and discover I've damaged the battery.
The 4A charger pairs to a battery that Jimmy re-celled for me. He had the charger at the time.
The 2A pairs to a soft pack battery that Jimmy made, althought the charger is a replacement for the original that blew.

Will the BMS take an extra 0.3v?
What voltage do bleed resistors generally come into play?

I use both packs in parallel as the hills around here mean that sag is big when using only one at a time. This way they perform better and are less stressed. Voltages always measured before connecting them together.

 

[Nealh]

If the chargers have an adjustable V pot then it is simple to use a VM to make the adjustment. Top balance depends on the BMS specs, top balance often occurs > 4.18v. Balance current is quite low at approx. 60ma - 80ma so the process is slow unless the balance is specific and set to a lower voltage.
The Swizzbee balance is 4.15v, smart BMS with uart/bt utilise user adjustment values as low as 4v.

Ideally the best BMS is a smart uart/bt type , one can then check balance via ones pc or phone.

If one has means of voltage readout when in use then an active balancer may be an option instead of a bms, they are voltage specific for the battery and top balance automatically all cells and are meant to also whilst discharging. If cells are within 0.1v they adjust at 0.5- 0.7a currenet and if over at 1.2a current, they have no lvc so one needs to monitor bottom voltage.
These balancers have a series of of leds that operate on & off when balance is in process, not much use for a cased battery as one can't see them doing their job unless said case had a clear panel where said balancer is located. They may be of use for softpack batteries where they could be mounted on the outside as these soft packs are mostly placed in a soft pouch or bag so are removed for charging.

 

[Benjahmin]

Thanks Neal.
So it would seem that a charger o/p voltage of 41.7, resulting in a battery at 41.6 is probably alright.
Can't check individual strings without severly cutting into wrapping etc. Not something I'm comfortable with as I like my house uncrispy !

 

[Nealh]

41.6/7 is pretty well balanced as long as the voltage stays that way nothing to worry about.
My swizzbee #1 battery is set for 4.15v balance via the LG BMS.