LiPo balance wire length vs gauge

[El_Steak]

I charge my LiPo packs with an RC Charger. My packs are deep in my rear panniers so I have to use balance connector extensions to be able to plug into the charger. Total length from pack to charger is over 3 feet with 22 AWG.

Using a celllog or battery medic, I haven't noticed any significant difference between the voltage measured right at the battery connector or at the end of the 3 feet extension.

I have seen it mentionned in a couple of places that for longer runs you have to increase the wire size to 20AWG or even 18AWG or you'll get errors in the readings.

Is there a rule of thumb for the proper length / gauge of balance wires ?

Note that those wires are strictly used for voltage monitoring and balancing. The only current going through them will be from the RC Charger shunt balancer (200ma-300ma?)

EDIT: the balancing wires for all cells have the exact same length.

 

[neptronix]

hmmm, interesting! 3 feet is a long way to go. Many people were warning me about even using the what.. 4 inch extenders?

I wonder if it is okay to do this long term. I would imagine that if you charge up to 4.1-4.15v, even if your balance wires set the readings off by 0.05v, your batteries shall remain happy little suckers.

How long have you been doing this, and are you doing bulk charging, or charging each battery separate?

 

[El_Steak]

I wonder if it is okay to do this long term. I would imagine that if you charge up to 4.1-4.15v, even if your balance wires set the readings off by 0.05v, your batteries shall remain happy little suckers.

How long have you been doing this, and are you doing bulk charging, or charging each battery separate?

I did this all summer long (maybe 75 cycles, I'm not sure). I rewire my pack from series to parallel (made some adapters) and charge the whole pack in 6s12p configuration using an iCharger 206B (300 watts). Max voltage is set to 4.16 and thats what I get when I measure close to the pack or at the end of the 3 feet extension.

I've grown tired of the pack rewiring and slow 300W charge so I'm now looking at a different charging solution for next season. Maybe bulk charge with BMS or multiple RC chargers on separate power supplies. Whatever I decide, I'll have some serious rewiring to do and I want to do it right. I know that larger is better for the wire, but its also bulkier and more cumbersome to manipulate.

 

[neptronix]

have you heard of the hyperion net duo 14s charger?

May just be the ticket for you. You could also go 52v with it if you add some 2s packs.
I've got a 10s setup now.. i may just buy that charger and go to 14s myself. Pretty appealing.

 

[El_Steak]

have you heard of the hyperion net duo 14s charger?

Yep, that's what I'm considering right now. I'm waiting to see if Gary can cut up a drop shipement deal for ES international buyers. I have a 24s pack so it would be 2 hyperion chargers. I already have the 4 x s350-24 meanwell powersupply required to run those beasts.