Battery stuff and experimenting

Good evening people

In another post I had a rant about regular battery maintenance and giving them a charge occasionally. I have a couple of the JIB’s I am working on, the battery’s were for all intents and purposes, dead. They came to me with dead buttons? In both cases the battery’s were at .comlt.

After cutting them out of the units I tried them on the charger and the charger never even woke up. Checked with the volt thing, and all four registered zero.

As I had nothing better to do apart from drink whiskey, I decided to try and bypass the protection circuits and hook the charger direct to the battery. As per the fuzzy pictures, the little circuit was exposed and bent out of the way. A voltage check directly to the battery told me that they were holding 2.75 volts, so were not in actual fact dead.

With the protection circuit moved out of the way it was possible to set them in the charger (Soshine ) and the charging light came up. It didn’t before. Light changed to green after two and a half hours. Checked the charge and reading 4.15v with the protection in place. Battery sizes are AW 18500, 1500mah. X 4. If this works I have saved a few bucks!!

The other circuit in the pictures is a external 4000mah charging pack, with zero output voltage, and charger not even looking at it.. Soldered up a 510 battery connection, soldered to the battery and used an ego charger. Seems to be working. Nothing getting hot and holding charge. When finished, the battery will be removed for another project.

There is no particular reason for this silly exercise other than curiosity, and I don’t have any spare batteries on hand, to continue playing with the JIB’s

I realize this exercise is not everybody’s cup of tea, and I am not suggesting anybody try this. Just mentioned it cos I find it interesting?? I don’t know what the lower voltage threshold is before the battery’s become completely useless and wont take a charge? Anybody?? Of course, with unprotected battery’s, this wont work!!

 

this seems to be a very basic problem with the current chargers ( and the jib itself) they require a voltage to trigger them and since the battery cutoff protection has cut in, well its a catch 22.
I have not had this problem as I use a number of different methods to charge, all of which apply voltage directly. For a whie I used a lab supply adjusted to 6v and a fixed constant current of 1.5A. relying on the protection circuit to halt charge when done, decided this was orobably not the safest method. Its MUCH faster than using a CV 4.2v charger though.
next time, save yourself the hassle of removing the protection circuit snd just add some joules directly .. limit the current by some means, car interior light globes are excellent.. and apply 12v from a good source, will only need a few seconds of charge to trigger the protectn to disable and then a normal charger will finish the job.

 

Thanks for that stoney. As you know the battery's on the JIB are hard wired and the whole thing needs to be dismantled. As these are the first two I have done, I am still on the learning curve!!! As mentioned I don't have any spare batteries to play around with, which is the reason I went to this trouble. The only stabilized power supply I have Is a twelve volt so I may dig it out and get it back into service. Could I connect up the twelve volts via the 510 connection instead of the 9 volt JIB charger, just to try before dismantling? The balancing system will only feed six to each battery???

 

Some chargers can be used to reset the protection circuit of the batt. Obviously yours did not and also the WF-139 charger can NOT.
I had a Li-Ion trip out and put it on a TR-001 for a second to reset it.
Recently had a Li-Poly trip several times due to over-current and just plugging it into a USB charger for a second to reset it.

 

I don't know how the charging circuit in the jib functions or what the supplied charger did.
Perhaps it was current limited ?
Are these a dual battery with an inbuilt balance doohickey ?

 

Yes the supplied charger were (are) 9v two amp.The connection is 510. The battery's are two in series and there is a balance circuit on the board.

 

oh i see what you are asking now robray .. if 9v will not 'untrip' the protection then I don't think 12v will either. It sounds like the balance cct is powered by the batterys so its not functioning and allowing the cells to charge once flat.
So i was saying to (probably disconnect batt first) give the cell a quick zap with a voltage first.
i did think of a reasonably safe way to do it tho .. put another lithium across it so they are paralelled. the protection cct will stop excessive current, I can't see a problem occurring doing it and I don't see why it needs to be disconnected first, do that for a minute or so and it should be ready to charge like normal.