Originally Posted by
christo930
Where are they getting the 8.4V from? They are describing it as an 8.4V battery pack, not that the unit is stepping up the voltage.
It looks like they are using 2 sets of 2 cells in parallel and the two sets are then wired in series like "=>=>---8.4V where each - is a cell for a 36.96 watt hour battery. But the normal voltage of a lithium ion cell is 3.6-3.7V. Seems kind of flaky.
From a light perspective, it looks like a great alternative and I especially like the Velcro battery pack holder/strap because theft is a huge issue in Philadelphia and it would be easy to just take it in a store with me (like I do with my GPS)
Has anyone ordered this and had it for a while? I certainly don't want to buy a light who's battery pack will fail in a few months and costs more than the whole package to replace (at $10 a cell + shipping).
Chris
Yes, the battery pack has 4 cells wired with two parallel sets of two cells in series. The 8.4V is the max. voltage of the charger and is higher than the nominal voltage of the Li Ion cells (2 x 3.7V or 7.4V). I haven't had mine very long yet, but it has been through several charge cycles and is working fine. There was a quality problem with the battery packs about a year ago, incl. some that caught fire due to inadequate control of the charging. I'm hoping the battery quality has improved and most indications are that it has.