Best Charging Options

TheSiege

100 W
Joined
Jul 17, 2016
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I have a 14s 52 21700 Lithium Ion volt pack. I havent gotten my charger in yet, but the pack does have a BMS. I do however have some chargers.
Which charger could I safely charge the pack with

13s 54.6v output Lithium Ion Charger
16s 58.4v output LiFePo4 Charger
48v Lead acid charger. Not sure the voltage since the charger doesnt list it, and it doesnt have voltage on the connector until it senses a connected battery.

Thanks
 
14S charger

If you sat and watched a higher-setpoint charge source, with an accurate DMM on the batt posts

in theory you'd be OK so long as you stopped between 57-58V. This is CC only charge cycle

58.8V absolute max, let it go higher can damage the pack, burn down the building...

But your BMS would likely not have time to balance, for that you need to sit at CV stage setpoint for a while.

Does your BMS show you the 14 cell-level voltages?

 
Actually that 58.4V would be fine, 4.17Vpc better than 4.2 for longevity.

Just the bulk power pair of leads right not a balancing Hobby charger?
 
TheSiege said:
13s 54.6v output Lithium Ion Charger
16s 58.4v output LiFePo4 Charger

Consider a used RSP-1600-48. It would be used as a "dumb" charger (no termination) but if you just need an occasional high rate charge it's a great option. You might want to limit the current if you are charging a smaller battery.
 
Lyric 3 wheel scooter. Its basically a stand up with a seat. I have about 7 of them
 
TheSiege said:
And a 14s daly charger so no cell level voltage readings
You mean BMS?

Ability to monitor cell level voltage is required for proper pack maintenance


 
Charger questions to ask for features to look for:

1. Variable voltage in the range you looking for,
2. Max, min amps
3. At what point does the charger turn off when charging is complete.


#1 - 14s = 4.2 x 14 = 58.8
to make those cells last longer, it is suggest to limit max voltage per cell to 4v, so that gives us

4x14 = 56v
56v is what you want your charge voltage to be at or lower (my perference)

#2 -
How many cells are in parallel and what are they?
Look up the cell specs and pick you max charge camps accordingly.

So if your cells have 1A max charge and 5 cells in parallel, I would stick to 5A max charge rate.

#3
This is important if you want to walk away while it charge and have the charger turn off.
I use CC/CV power supplies to charge my cells or use a Riden RD6012w batt charge feature to charge my cells.

Most 2 stage chargers turn off once the amps go down to say 0.200 amps.

Hope that helps,
 
gobi said:
to make those cells last longer, it is suggest to limit max voltage per cell to 4v, so that gives us

4x14 = 56v
56v is what you want your charge voltage to be at or lower (my perference)
There is no added longevity if you want to use pack capacity, by terminating charge below 4.10, even 4.15Vpc.

Auto charge termination based on trailing current is great, but too bad it is fixed at such a tiny mA rate.
 
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