Where can I find this tool?

This is a corner of a Ryobi 40 volt lithium battery pack. It has developed an issue where the tool it's powering will suddenly stop under load, but restarts after short rest.

I'm guessing that one of the internal cells is failing. Now that I have a hobby charger capable of lithium ion balancing, I'm interested to see if the weak cell could be recovered.

I've seen these type of security bits before but I'm not sure where I can purchase one to access this battery case.



These batteries cost $100, and I've actually discarded one before I knew anything about Hobby Chargers. I'd like to try and not have to discard this one. Thank you.

 

Thank you for that reference. I see that a Harbor Freight Tool in my neighborhood shows a similar product. I'm going to take this battery over there and if it doesn't fit I'll be ordering that one off of Amazon. Thank you so very much.

 

First breakdown of ONE + for you.











I purchased the 100 piece security bit set from Harbor Freight. The tamper-proof Torx bit number T10 fit the OnePlus perfectly. Of the four screws, one of them is filled over the top with a barrier that you have to dig your way through. Took me about 10 minutes with an exacto blade.



Seems like a standard form factor .Anyway, next task will be to figure out how to apply this information to a hobby charger

Thank you everyone for your help. I'll post the results as soon as I'm able to work through a few Cycles

 

Bisco, the results are going to take a while. Of the five batteries, four of them are near zero volts. One battery had a little over two volts in it and this is the one that I'm starting with first.

There is something strange going on with this SkyRC B6AC charger. It would not detect the lithium-ion battery. I went to the RC forums, and they suggested putting some energy into the cell, enuff to get it recognized. The procedure is not exactly recommended, but did get the cell 'recognized' and on a charging profile.

We'll see what happens.

 

29th week of 2012, so mid July 2012. This is a battery I purchased for my father (who lets his tools set for long periods of time).

For a 1300 mAH battery it's showing a capacity of 1019 mAH after 2 cycles. Going to give it one more cycle.

 

The results are in.

4 of the 5 Li -Ion cells were completely dead. The only surviving cell charged up to a final capacity of 1,014 mAH, but is currently only holding at 3.27V.

At first I thought perhaps the battery management circuitry might be influencing the readings so I went further and completely disassembled the One +. Unfortunately, the individual cells measured exactly the same as they had before, so nothing gained by that exercise.

Since I am not the hobbyist who collects rechargeable cells and retasks them, I don't know if this was a worthwhile effort. If I had newer battery packs that had seen frequent use, maybe the outcome would be more positive.

 

True, but the time needed to split the battery holder, and re-solder the leads could be the deal breaker.

I have yet to open the 40V pack. Unlike my Dad's One + kit, the 40V gets regular use, so maybe there is only one weak link that could be replaced. If you interested, I will post that breakdown.

 

I don't have pictures to show, but I found the battery pack to be well-made. The solder points were all smooth and shiny, the connection tabs are solid. Nothing on the circuit board displayed corrosion, erosion, or heat stress. Not sure if Li-Ion reacts well to heat and humidity, but there are plenty of both in SW Texas.