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To repair or not?

Posted: Sun, 31 May 2015, 23:45
by EV2Go
My Rider One bike GPS has been slowly getting less and less charge time for several years now. A little while ago it just stopped turning on.

Before I spend cash on replacing the battery I have a couple of questions. Firstly the Samsung ICR18650-22E (2200mAh) is showing 2.93v whereas I believe they are meant to be 3.7v. I'm not sure if it was taking charge when plugged in because there are no lights to indicate.

Is 2.93v too low for the GPS to fire up or have I got another problem?

The other thing is there are plenty of 18650 batteries on the market up to 6Ah. Now I suspect they should be fatter to accommodate the extra capacity, is this right or wrong?

Image

To repair or not?

Posted: Mon, 01 Jun 2015, 02:00
by Johny
First bit. 2.9V would probably trigger an undervoltage lockout on the GPS. I have read that 18650 cells do not come any higher than 2.8AH and ones that claim higher are fakes. All would fit as 18650 refers to diameter and length.

Sent from phone...

To repair or not?

Posted: Mon, 01 Jun 2015, 02:08
by EV2Go
Thanks Johny. I thought they were a fixed size format. There is a 12v option for powering off the bike might see if I can get it working off it.

To repair or not?

Posted: Mon, 01 Jun 2015, 02:46
by coulomb
EV2Go wrote: I'm not sure if it was taking charge when plugged in because there are no lights to indicate.

If you can, watch the voltage with a multimeter when is is charging. I expect 2.9 V to be so low that you'd see quite a bit of change of voltage as it charges.

If it shoots up very quickly, say to > 3.5 V in less than 10 seconds (wild guess), I'd suspect that the cell has a high internal resistance, and is not usable. Actually, I strongly suspect that to be the case, without seeing the voltage, but this should confirm it.

Edit: if it's not convenient to measure while charging, just measure after it has been on charge for a minute or two. You can obviously measure the voltage when not charging. I would expect to see some change in the voltage after even a short charge like that.

I suppose it could be the charger; if so the cell might still be OK, just lost come capacity. I would use a bench power supply to charge it independently of the built-in charger, but you may not have one handy. If you do, use a charge current of perhaps 200-250 mA (around 0.1 C) for safety, and don't let it and a voltmeter out of your sight. I've seen the fires that improper charging can do to LiPos, and even laptop-like (LiCo?) types.

To repair or not?

Posted: Mon, 01 Jun 2015, 03:56
by Adverse Effects
Dude get over here i'll give you a BUNCH of new 18650's i have sitting here and nothing to do with them

as for any 18650 that says its over 3400mah is a out right lie and the 3400mah ones are about $15 each

18650's are 4.2V full and 3.2 flat but i have seen them taken down to sub 3V lots of times and still work ok

i have a RC battery charger that can test capacity and all that stuff if you want to drop off your one here but your better off just taking one of the free ones i have already tested here :-)

never buy any of the "fire" ones turefire, trustfire, ultrafire and so on and on there are no "real" genuine brands with thos names

[tube]https://youtu.be/eOshOXcSkDA[/tube]

To repair or not?

Posted: Mon, 01 Jun 2015, 06:58
by EV2Go
Never thought to try and see if the charger was still working... Threw the meter on it and it putting out 5.23v.

Uploading a video at the moment and will link to tomorrow once up, but battery is taking charge slowly as expected.

Will charge to 3.7v tonight and let it sit over night to see what reading I get tomorrow.

Thanks for the video link Ivan, amazing what people will try pass off.

To repair or not?

Posted: Mon, 01 Jun 2015, 16:49
by EV2Go
Uploaded the video of the battery charging last night. Was at 3.49v when I went to be and was on 3.49v this morning, so while it doesn't seem to hold a load for long, it does appear to hold voltage ok. Tried some more testing this morning new video coming.


To repair or not?

Posted: Mon, 01 Jun 2015, 16:49
by offgridQLD
Whats this Flour? .... Image Image That's what customs said to Image

Kurt


To repair or not?

Posted: Mon, 01 Jun 2015, 16:55
by Johny
Here is a set of tests on 18650 cells I stumbled upon. I thought I got the link here but maybe not.
http://lygte-info.dk/review/batteries20 ... %20UK.html

To repair or not?

Posted: Mon, 01 Jun 2015, 16:57
by Johny
Paul 3.49V for a LiPo is not anywhere near reasonably charged. I'd expect at least 4V after an overnight charge.
He's dead Dave....

To repair or not?

Posted: Mon, 01 Jun 2015, 17:04
by EV2Go
Johny no I didn't leave it on overnight, as didn't have the BMS hooked up (nor trust it), I was charging before I went to bed and stopped the charging process at 3.49v and just left it without anything hooked up.

To repair or not?

Posted: Mon, 01 Jun 2015, 17:57
by EV2Go
Bit more playing around and I got it to work

Currently slow trickling up to 4.06v. Now to see if I can get it to work off the 12v side of things.