How to see if a battery is protected

Batteries and Chargers Rechargeable Batteries
17

Very useful . Thanks! :bigsmile:

18

Welcome to the Forum! :beer:

19

:bigsmile: Thanks

20

Great post wiyh many informations !! Many thanks !

21

:8)

22

Brilliant info that newbies like me can keep coming back to as we forget :slight_smile: ,cheers hkj

23

Subscribing so I can point others to this info

Phil

24

Great info. Very informative. Was just wondering if my batteries were protected or not, and Robo referred me to the thread. Turns out my batteries are protected.

Thanx.

25

Just came from your site. I believe there are some double posts in last group of pics.

26

Oops, fixed, Thanks.

27

Fantastic little guide, HKJ. Thanks again!

28

Nice information to check battery protected or not. Thanks for sharing this useful information

29

Thanks HKJ.
Will the added protection board cause difference in diameters?

30

It will make battery longer but the diameter will be almost the same or just slightly larger (~0.5mm or so) because when you add protection you have to use one more layer of wrapping foil because there is an additional ā€œflatā€ wire that goes from protection PCB to opposite pole and it needs to be isolated.

31

Usual yes, due to the strip fro plus down to the protection board at the minus end.
Some just add a new layer of wrap, other removes the old wrap or buy unwrapped batteries to start with.

The length of a 18650 cells can be up to about 72mm, but usual is below 70mm

Accepting 19mm diameter and from 65 to 72mm in length will handle as good as all sizes 18650. There is also the issue about flat vs. button top, the extra length due to that is included in the 70/72mm, but remember that on a flattop the isolation can be a few tenths mm above the plus pole.

32

Some (like Soshine) have their protection on the positive pole and only one wrapper layer. Such cells have the same diameter as unprotected cells.

33

Want to see if its protected? Short it with 10 gauge or similar cable if it gets really hot or blows up its probably not protected. If it does nothing it probably has a protection circuit.

34

:open_mouth:
or just send them to mattjk so he could test them by shorting + a - !!!
If he answers after testing = its protected,
if no answer for 24 h or more = itā€™s not protected and he is in hospital waiting for skin graftingā€¦

35

Unprotected cells with PTC wonā€™t heat up cables because they limit short circuit current (but I donā€™t know what ā€œ10 gaugeā€ means).

36

gauge (AWG) is the measure the yanks use for the cable size. 10 is good for about 50 amps depending on length

And yes i was obviously kidding!