Is there a way to detect if li-ion battery is used or not? - Page 1
Forum section: electronics / beginners

author: m4rtin
author_rank: Regular Contributor
timestamp: August 13, 2016, 10:38:16 pm
content: Is there a way to detect if laptop or mobile li-ion battery is used or not? For example on Android platform there are plenty of apps which show the number of charge cycles, but all of those apps simply seem to work in the background and count the number of times charger was connected and disconnected. In order to really count the charge cycles there should be some sort of non-volatile memory in the battery I guess.. Maybe there are some other ways to detect if li-ion battery is used or not?

author: wraper
author_rank: Unknown
timestamp: August 13, 2016, 11:13:56 pm
content: If you want to buy laptop battery on ebay, then most of them are recycled crap or counterfeits. Chinese usually reset the controller, so they look like new if checked with programs. Although capacity is certainly not as new. Mobile phone battery unlikely will be possible to check at all, they usually don't hold any usage data.

author: IanB
author_rank: Super Contributor
timestamp: August 13, 2016, 11:28:06 pm
content: If you are serious about it, then you could analyze the battery performance and compare it to the manufacturer's specification.For example, most batteries have a nameplate mAh rating on the label, and if the battery is from a reputable source then it will meet that rating when new. So one test you can do is measure the capacity and see if it matches the label. As Li-ion batteries age their capacity generally decreases, so a failure to meet the label specification probably indicates a used battery.

author: m4rtin
author_rank: Regular Contributor
timestamp: August 14, 2016, 09:00:16 am
content: Quote from: wraper on August 13, 2016, 11:13:56 pmOk. The battery I was asking for is a mobile battery. However, out of curiosity, I checked for example, my definitely original laptop battery and this does not seem to support cycle count either:Code:root@T60:~# cat /sys/class/power_supply/BAT0/cycle_count0root@T60:~#..while it does show lots of other information for this battery like a manufacturer:Code:root@T60:~# cat /sys/class/power_supply/BAT0/manufacturerSANYOroot@T60:~#Quote from: IanB on August 13, 2016, 11:28:06 pmThis particular battery I was asking for, is a 2800mAh Li-ion battery for an Android phone. However, I guess there is probably no app out there which can draw for example 1.4A current so that I could see if the battery dies around 2 hours. I guess the only option is to get a battery from reliable source, run a battery benchmark under fixed conditions(screen brightness level, Wi-Fi turned off, etc) and then run the very same benchmark with the second battery under those same conditions?

author: Kilrah
author_rank: Unknown
timestamp: August 14, 2016, 09:08:58 am
content: If you really want to know capacity just get an RC universal charger/discharger and run a capacity check.

author: m4rtin
author_rank: Regular Contributor
timestamp: August 14, 2016, 11:27:22 am
content: Quote from: Kilrah on August 14, 2016, 09:08:58 amI would like to know, if the batttery, whichs I just bought, is a new one or actually used.

author: IanB
author_rank: Super Contributor
timestamp: August 14, 2016, 12:42:41 pm
content: Quote from: m4rtin on August 14, 2016, 11:27:22 amWhen you bought it, did you pay the price of a new battery or a reclaimed battery? If you paid the price of a reclaimed battery, it is probably a previously used battery.

author: Kilrah
author_rank: Unknown
timestamp: August 14, 2016, 04:03:07 pm
content: Quote from: m4rtin on August 14, 2016, 11:27:22 amIF that particular battery type is "smart" and holds a usage counter then look at that, but unless it does there's no way to know. Even if it was used say 100 times it would still be basically indistinguishable from new.You can only know in what "shape" it is now you've got it.As mentioned even with "smart" batteries you can't know whether they've been tampered with or not.

author: amyk
author_rank: Super Contributor
timestamp: August 14, 2016, 10:04:44 pm
content: It will almost certainly have been cycled at least once after assembly for QC purposes, so in that sense every (good) battery you buy is "used". But what's more important here is whether the cell meets capacity specifications, and more interestingly, due to how capacity degradation is typically somewhat exponential, a cell that is "new" might show a much higher capacity that degrades quickly than one that's been through a few hundred cycles already and is thus past the "knee" of the degradation curve.