RE: Li-PO or NiCd Pros and Cons
Yes you can charge packs in parallel, two 10C 1500 packs at up to 3 amps. I do it all the time, but I make sure the packs measure very close to the same voltage first. Somewhere I read that doesn't matter because they equalize themselves but I don't take any chances with lipos. I am always neaby when they are charging.
This is taken from the FMA site when you click on lithium batteries.
WARNING
Safety precautions
for Lithium Polymer and NiCd cells/packs stocked by FMA Direct
1. Never fast-charge any battery type unattended.
2. Never charge LiPo cells/packs at any rate unattended.
3. Only charge LiPo cells/packs with a charger designed specifically for lithium polymer chemistry. Example chargers include the Kokam USA, LIPO 402, LIPO 102 and LIPO 202; Bishop Power Products Apache S1215 and S1500; Great Planes Triton; and Schulze chargers with lithium charging capability.
4. LiPo cells can ignite because of unmatched cell capacity or voltage, cell damage, charger failure, incorrect charger settings and other factors.
5. Always use the correct charging voltage. LiPo cells/packs may ignite if connected to a charger supplying more than 6 volts per cell.
6. Always assure the charger is working properly.
7. Always charge LiPo cells/packs where no harm can result, no matter what happens.
8. Never charge a cell/pack in a model. A hot pack may ignite wood, foam or plastic.
9. Never charge a cell/pack inside a motor vehicle, or in a vehicle’s engine compartment.
10. Never charge a cell/pack on a wooden workbench, or on any flammable material.
11. If a cell/pack is involved in a crash:
a. Remove the cell/pack from the model.
b. Carefully inspect the cell/pack for shorts in the wiring or connections. If in doubt, cut all wires from the cell/pack.
c. Disassemble the pack.
d. Inspect cells for dents, cracks and splits. Dispose of damaged cells (see below).
12. Dispose of cells/packs as follows:
a. Discharge: with the cell/pack in a safe area, connect a moderate resistance across the terminals until the cell/pack is discharged. CAUTION: cell/pack may be hot!
b. Discard:
- NiMH: place in regular trash.
- NiCd: recycle (cadmium is toxic).
- LiPo: puncture plastic envelope, immerse in salt water for several hours, place in regular trash.
13. Handle all cells/packs with care, as they can deliver high currents if shorted. Shorting by a ring, for example, will remove a finger.
14. Always store cells/packs in a secure location where they cannot be shorted or handled by children.
15. When constructing a pack, use only cells of the same capacity (mAh). During continued use of a pack, periodically check individual cells after discharge and before charging to verify cell voltages are within 0.1V of each other. If a pack has become unbalanced (i.e., cell voltages are more than 0.1V apart), restore balance by charging the cells individually to 4.2V before reconnecting as a pack.
16. Using FMA's Safety Guard voltage limiter while charging series-connected packs is strongly recommended. Note that cells in a pack should still be periodically checked for proper balance.
FMA, Inc. and KOKAM USA, its successors, heirs and assigns are not responsible in any way for any and all bodily injurie(s) and/or property damage that may occur from the use of or caused by in any way the lithium Polymer and NiCd cells/packs stocked and or distributed by FMA, Inc. and KOKAM USA.