Forum menu
In here as it seems most bike lights use 18650 batteries.
I've about 12 batteries that a guy at work was testing for me last year but he's quit so I'm trying to work out which of my collection are good and which are bad.
Any suggestions on a simple tester? I was recommended a multimeter but then told that'd only give me half the story.
I've already got 2 chargers so ideally I don't want to get another even if it includes one.
Multimeter.
Charge then all up and check to see if there around 4.2volt. They should keep that charge for at least a few days.
Those that dont need disposing of.
low tech way: charge em up..... put in a torch and time how long to discharge.
slightly better way: charge em up in a smart charger (you can get decent/cheap ones like the xtar vc4).
4.2v from a 3.7v battery? I thought it was all about the drop when a load is applied not how well it holds voltage
[url= https://www.google.co.uk/search?client=opera&q=imax+b6&sourceid=opera&ie=UTF-8&oe=UTF-8 ]I have an IMax B6, its cheap enough and will charge and tell you the capacity of almost anything.[/url]
[quote=thepodge ]4.2v from a 3.7v battery? I thought it was all about the drop when a load is applied not how well it holds voltage
3.7V is nominal, which is mid discharge, 4.2V fully charged. Drop when load applied just tells you the internal resistance (which shouldn't vary that much unless cell is completely knackered), the only really good way to test cells is with a rundown test. The low tech see how long they last in a torch is actually a really good test.
you need to know the internal resistance too, so when assembling into a pack you match similar cells
Anything I can use as a rundown requires at least two batteries so although it'll narrow it down it'll not be the easiest or best way.
Moon on a stick sir? you can get a cheap single cell LED torch for a fiver to do burn tests.
or, you can drop ~20-30 on a B6 and measure discharge through that.
personally i just measure how much charge they take, then flatten them and remeasure.