I honestly wish i knew more...when i read thru this thread i get even more confused and lost....what/how are you guys charging these little sweet cheap packs.
Let me google that for you.
In short, you need a balance charger to keep the two 3.7V cells balanced while charging. Each 3.7V cell in a LiPO battery (of any size) should ideally be balanced, or the same voltage as the others in the pack. If one cell is abnormally higher or lower than the others, the battery cells are stressed and will eventually fail (sometimes quickly). You can work out the size of a LiPO battery from its S rating - 1S = 3.7V cell, so 2S = 2x3.7V cells and 6S = 6x3.7V cells, etc etc. You'll be using maybe 1S but probably 2S for your Trekker/Micro if you change to LiPO batteries.
A 2S LiPO battery's operating range is from 8.4V (full) to between 6.4V and 7.0V (empty; depending on user preference and LiPO cut-off settings; higher is safer). Some LiPO batteries have balancing and cut-off circuitry built-in, but the more common versions are simply cells in a packet with a power plug and balancing plug. These simpler batteries rely on LiPO low-voltage cut-off circuitry in your model's ESC (or separately) or else for the user to intervene when the voltage visibly drops (as soon as max wheel speed decreases dramatically - definitely the inferior way to 'care' for your LiPOs!).
Personally, I use the following simple LiPO setup:
- Turnigy 370mAh 2S LiPO battery pack (
link)
(
This 460mAh one is a shade fatter but still fits in my Trekker)
- HXT LiPO battery monitor (
link)
*
- Turnigy 200W Balance Charger (
link)
- Fiberglass fireproof LiPO charging bag (
link)
* mounted on my model so I can see when the battery is getting low/unbalanced. The balance plug on the battery connects to this, enabling the device to read the voltage per cell (same with how the charger works; it trickle-charges through the balance plug to top-up or drain individual cells to ensure they're all balanced precisely).