View Single Post
Old 08-31-2014, 11:06 AM   #97 (permalink)
IamIan
Master EcoModder
 
IamIan's Avatar
 
Join Date: Dec 2010
Location: RI
Posts: 692
Thanks: 371
Thanked 227 Times in 140 Posts
Quote:
Originally Posted by TurnNBurn View Post
I have a question since my memory is pretty much dead from this thread.

Could I possibly use two iChargers to charge the 9 packs (18 cells) ? If not iChargers, some other replacement lifepo4 chargers. Is there something not recommended about this setup?
9 sub-packs of 18 cells each or 162 total cells in the whole pack ??

If that's what you mean .. there is no iCharger that can do all 162 cells in series at once.

You either need to:

Option #1> Charge each subpack of 18 cells separately ... can be one at a time with the same iCharger .. or all at once with 9 iChargers (one for each sub-pack).

Option #2> electrically disconnect all the series connections between the 9 sub-packs , than connect all 9 subpacks are in parallel... and use iCharger to charge the combined parallel pack.

- - - - - - -

There are a variety of other charger options out there other than the iCharger ... they all have pros and cons .. use whatever has the options you like / want.

My general recommendation is that you get one that is rated for a bit more than you need / want to use it for .. give yourself a buffer .. I usually aim for at least about a ~25% buffer.

- - - - - - -

Reasons for not?

Parallel cells :
You don't have cell level charge / discharge control .. you're just taking a short cut and treating all the parallel cells as if they were just 1 bigger capacity cell .. which is ~99% of the time fine .. but is not 100% accurate .. although you might not care about the difference.

Parallel Packs:
If you don't have cell level control .. it's a bad idea .. now that control can be subpack level feedback BMS boards built into each subpack , and the charger/discharge itself only sees it as one whole pack ... but that cell level control is a good idea... without it you are risking destructive fire.

Series Packs while connected:
Some Charger/Discharger's are fine with it , just plug and go ... depending on the type of isolation they have from input to output .. other units need you to use some added isolation yourself ... that added isolation might be on the source side (AC) separating from charge to charge .. or the output side (between subpacks)... but some have it built in and don't need any added external isolation.
__________________
Life Long Energy Efficiency Enthusiast
2000 Honda Insight - LiFePO4 PHEV - Solar
2020 Inmotion V11 PEV ~30miles/kwh
  Reply With Quote