For those looking for a Li charger...
 

The TME Xtrema has been around a while now and I really love mine. But what really stands out in my opinion is the great customer service I have received. Twice (once a year or so back, and one last week) I sent the company emails inquiring about various aspects of the charger and both times received complete and detailed responses within 2 business days.

In the most recent email, one of the things I inquired about is the power limit. The charger is good for 10s and 8A, but "only" 180w (and it is truly and exactly 180w - I checked). The reply I got was that they are looking at raising the limit through firmware! Maybe not for the full 336w (10s@8A), but higher than 180w. The case may need extra heatsinking though, but I already took care of that. :smile:

Another topic was the v/cell setting. If set at "A123 mode", which is 3.6v/cell, the min voltage required is 2.0v/cell. For all voltage threshold settings above 3.6v/cell, the min voltage required is 3v/cell. Don't know if anyone cares, but there it is.

I also told him about how I use the Xtrema to charge NiMHs despite it being a Li-only charger. I do this by setting a cell count that is above the min V setting, yet won't peak out below the NiMH pack voltage. Then, I use the temp cutoff feature set at 105*F as the "peak detection". Works great. Not as easy to use as a real NiMH charger, but works in the field. His response was "Very interesting technique. As always be very careful, although NiMh batteries do not catch fire on their own, I have heard storied of them exploding and throwing shrapnel when severely overcharged.". Not exactly a "don't do this" type of response. :wink:

So anway, just thought I'd pass this info on for those who have, or are looking to get this charger.

I'll second what Brian said about the Xtrema charger. Great charger. Works flawless and its easy to use. I've been using mine for about a year now.

I havent run into an issue with the 180W limit. The biggest pack I charge is a 8000mah 5s pack and it charges just fine.

That's pretty close though at 168w right at CC/CV threshold...

One of the other things I asked him about is creating a special charger just for me that is 12s/20A/1000w capable, and has to have a few other design parameters. We're still working on that. :smile:

I to have two of these and they are awsome, They have not given me any trouble in the year i have had them. I have charged everything from my 2s 1800 hyperion to my 8000 3s packs and no trouble