Question on the new charger and parallel charging using the Power 8 charger.
.... (trying to keep costs down....)
I am thinking about a lithium pack for a chair for my daughter. As always cost is a problem..... (I KNOW LONG TERM IT PAYS FOR ITSELF)
One cost is the charger..... at around $240 for one, that would be close to $500 if I need 2.
The manual has a section on parallel charging..... (some of us actually read the thing.
)
So. It says I need to keep each pack the same... That means either
12S at 44.4 volts
or
14S at 51.8 (which is stretching the 50 volt controller...)
So several questions:
1) How well would it actually work using a single charger, if I split my pack into 2 sets with the same count and only one charger? I know charging time would double, but i think we can adapt for that..... if we charge nightly to keep it charged up.....
2) If I went to 14s, am I pushing the controller to far? (I seem to remember that the cells drop a little, so it would not be at 51 other than the first few minutes ..... I hope..
3) If I went to 12s, how much would I be giving up? (top speed, higher load on current because of slightly higher current)
Anyhow here is the section of the manual that I am basing this discussion on (from the power 8 manual.... )
Parallel charging takes advantage of the PowerLab 8’s high power output. After connecting packs using Safe Parallel Adapters, simply tell PowerLab 8 how many packs are attached—charge/discharge rates are automatically divided among the packs
PowerLab 8 can charge, discharge or cycle up to nine LiPo or A123 packs in parallel. Parallel operations can save a lot of time, but you must follow these rules: Always use Safe Parallel Adapters (available at the REVOLECTRIX Web site). Never use standard adapters. Connect only one pack per Safe Parallel Adapter. Daisy-chain multiple adapters! Parallel operations using Safe Parallel Adapters requires that you connect both the balance wires and discharge wires to the PowerLab 8. Always observe proper polarity! Packs must have the same cell count. Packs must be the same chemistry. The best way to connect discharge wires in parallel is to stack the plugs on the safety banana cables like this:
Summary: parallel charging. Components: 1 PowerLab 8 1 power source 1 Safe Parallel Adapter for each pack (do not use standard adapters) 2 or more packs (above 9 packs in parallel, you are responsible for determining the charge/discharge current for each pack) Optional FUIM3 for computer support
PowerLab 8 mode (Normal or Expansion Channel): Normal.
PowerLab 8 maximum charge power: up to 672W charge to each of two packs charged in parallel using 24VDC/1700W power source.
Constraints: 1 pack per adapter. Check pack polarity. Same cell count for all packs. Use discharge leads
.