Li-ion max voltage
Decided to try and charge one of my non-Lupine 7.4v 2600mah packs with my Lupine Wiesel V3 charger....The charger seemed to work correctly with the led lit up while charging and going out when charged....
The battery measures 8.50v.......I've read that the max for this pack is 8.40v.......Am I just being critical or is this overcharged and I shouldn't use the charger??
The same batteries with balance taps charged with my Hyperion balance charger ended up at 8.29v and 8.26v.
Assuming you've got an accurate meter, 8.50 volts is overcharged and I'd be concerned about that too. Way better to be slightly uncharged like you are getting with your balance charger than to be over and risk battery damage.
Originally Posted by bncrshr77
That is overcharged. Don't do that again.
Hopefully they are both sitting at 4.25V, which isn't that much over the recommended 4.2V cutoff, but they might be slightly out of balance with one slightly higher, which could prove dangerous.
Make it a point to check the voltage at the balance taps after charging and after use for the next five or so charges on the normal setup. If things get weird, do a 'bounce test' with the pack.
(A bounce test is a highly technical test where you carefully hold the battery above a li-ion recycling bin and then release. If the pack stays at the bottom of the bin, it was bad. If it bounces out, you keep it.)
That's kinda what I was thinking but I'll wait do some more reading on it.....
It's got a tenergy PCB that is rated for overcharge protection at 4.35±0.025V....
I'm charging my 3000mAh unprotected Ultrafires with Soshine LiIon smart charger and they always top out at 4.35V. Been doing so for more than a year and no fire in my roof since. Samsung 2900mAh cells are rated to be actually 2900mAh when charged up to 4.35V. All the fuss about LiIon cells is so overrated. I managed to discharge one of those particular cells down to 0.5V several times and it always recovered in a day or so and still holds the same charge as the other cells.
I noticed that alot of the protection boards have a rating of 4.35v overcharge cutoff.
This kinda scares me as I don't want my cells going over 4.2v.
Should we be worried about boards that are rated as such?
Or are they rated that way for a reason?
Inquiring minds want to know.
Look, whatever happens, don't fight the mountain.
Yeah.....I was kind of wondering why the PCB in my tenergy pack would be rated for a 4.35v cut-off if it is dangerous.....I would assume that it is safe until reaching 4.35v.....Who knows??
Originally Posted by Toaster79
+1. I have badly abused one set of my unprotected 18650s with no noticeable ill effect. Hence the reason for my tongue in cheek post..
And more batteries
The protection board overcharge cutoff is intentionally set higher than 4.2V. It's only meant to kick in if the charger doesn't do it's job and stop at 4.2V.
After several more discharge/charge cycles with the Lupine charger it seems to be fairly consistent at charging packs to between 8.28 and 8.35v....This is with Tenergy packs and an LG pack...I'm convinced it's good to go..
Wiesel is quiet good.
your volt meter might not have the digits, so it rounds up.
did measure 8.47V on final charge.
this is within +/- 1%
while some other chargers, are more like 2-5%
for using the Wiesel, use only good cells, and of course be careful.
on charging ultrafires to 4.35V,.... just don't , unless you know the cells are rated for that.
my favorite , right now for 18650 cobalt type, is the samsung 28A with 4.3V ,
on an hyperion charger with 80mV+, even with 4.2V charger they are good.
notes: charging to 4.1V or less than 4.2V per cell, extents the life and safety.
common thing with. other thing is, if you can't measure / balance the pack,
chances are, that even a regular 4.2V /cell charge, might overcharge one side.
that's why most of the chargers, do less, say 4.15V / cell to have a little margin.
and doing a full charge, to the brim, and then just throw it in the bag, for weeks or month,
is not a good practice. of course, unless you have a processor controlled charger, you can't really do anything about that.
for the wiesel, best to keep the mix to a minimum, on the menu, panasonic cells 2900
for connectors, stenlight stuff should fit, otherwise give me a buzz for cables/adaptersmtbl.robs-x.com
oh, and there might be a fine-print, with your Lupine service, using different stuff,
and with any batteries, be careful and responsible. cheers