Backyard Aquaponics
A place to discuss aquaponics

I bought some batteries the other day for a project I'm working on.

All three 18650 batteries have been charged and discharged 4 times.

The two Ultrafire batteries are listed as 3000mAh, but tested as 425mHa, and 421mAh.

It's almost as if they are being dishonest. I have 4 more Ultrafire that also test at similar levels.

It's nice to be able to test them, because then you get them for free (although they are pointless)

The Imalent one (from a headlamp I bought) is listed at 2600mAh, but tested at 3203mAh. It's nice when someone gives you more than you paid for.





*Tested on Opus BT-C3100

That tester Bull? Is it part of a charger or a stand alone unit?

I use a few 18650 batteries and would be handy to be able to properly test them.

It's a charger. I did bit of research and it seemed to be good. Can charge 4 different batteries of different size and chemistry, at the same time.

Opus BT-C3100

I just threw out a stack of rechargeables that I could never figure out the good from the bad. And also found a stack that have since been donated to some friend's kids for toys etc. I gave them my old chargers as well, although it's worth keeping an unsmart charger because this one will not charge a battery if it is completely flat.

You can either put a battery with zero volts on a non-smart charger for a few seconds, or just stand two batteries one good, one bad, - terminal down on a piece of foil, and put a different piece of foil across the + terminals for a few seconds to achieve a small charge in the empty battery.

This charger does a full charge then discharges to check capacity, then charges again.

Also does a refresh thing where it charges and discharges three times... ?maybe for nicads

It's nice to be able to show the seller that their batteries are not the real deal, and get your money back.

I got a completely free food dehydrator last week because it wasnt to advertised spec happy me. (Unrelated to this topic in any way)

Thanks for that. I will look into getting one.

I use a mix of brand name 18650s that came with my torches and others I have purchased for various projects.

Will be good to test them and see what the state of the older ones are like and if the newer ones are as advertised.

I'm guessing that inside those batteries is a really thin AA or something

Hmmm interesting... the two lesser batteries weigh 33g and the other good one weighs 54g (digital kitchen scales in 1g increments).

There is a page on the web where they pulled a fake ultrafire apart, inside there was one of the shorter lithium rechargeables.

Seems pretty common practice with the cheaper ones to be less rating than advertised.

I will weigh my various brands and see what the result is.

The 18650 batteries are pretty useful. Lots of capacity, no real self discharge, and around $10 each for a decent one.

I want to make a bird scarer to keep my goldfish safe from cats and birds. Mrs Bullwinkle watched a cat drinking from the IBC the other day, and I wonder how many I've lost.

Thought I already posted this?

NCR 3400mA 50g

Ultrafire 3000mA 42g

Wolfeyes 2200mA 44g

Blazar 3400mA 48g



Keen to get the tester so I can check the actual ratings.

Where are you in SA? (roughly)

I can test your batteries for you (depending on how many there are

Mitchell Park, near Marion.

But no problem, I have ordered a charger/tester which will be here later this week!!

Oh cool.

A quick update on this. My charger arrived last week and has been running since.

So good being able to know which batteries are losing capacity or are just plain duds.

The NCR and blazar batteries all tested fine and at their rated capacity.

2 of the wolfeyes which have done a lot of work and are probably approaching 10 years old tested well under half, one being about a tenth of capacity. No real suprise there. One of the wolfeyes, which I am guessing is a more recent one still tests fine.

And Finally the Ultrafires :-)
Both are relativity new, about 3 or 4 years old. One tested at a 1/4 of capacity the other about half. Guess I will never buy them again.

Certainly worth getting something that can test these batteries.

You did well getting that much out of the Ultrafires.

Mine were new and tested at nowhere near that.


Two people have bought that charger.tester as a result of my banging on about it. I should start an Amazon drop shipping company, and start making those irritating youtube ads

Haha, anyone who uses rechargeable batteries knows how useful being able to test the capacity is. You would have an easy job selling them once people knew it was available.