For those looking for a Li charger...

[BrianG]

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.

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.

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

[jhautz]

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.

[BrianG]

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.

[crazyjr]

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