I have some of those batteries which are about 40 years old, Panasonics made in Japan and had been used in jet plane display boards. I used to peel them out of laptop batteries pack. So far I have only found 1 in a hundred which go bad. Its always the charging unit that goes bad. Careful taking any of these apart and go slow and be smart. There is a lot of power which could burn your place down. Not a toy. I managed to retrofit most of my older flashlights to accommodate them. Really got tired of buying batteries or having them leak and destroy equipment. I did figure out that those tabs were difficult to solder so I like the welder method. Thanks
@@OhmSteader yeah. I’ve only started refurbishing tool batteries the past few months but I’ve worked with lithium batteries for years with other types of electronics. I have other vids recently posted about how I test and revive over discharged batteries. These shells I have failed being revived so I’m going to rebuild them all.
----------------------------------------------- snap in the battery and get the same results I have a Ryobi battery and it charge full . put battery run my weed eater it will run 2 minutes and dies recharge use it again the same results . need to drain the battery how do I do that only have weed eater --------------------------------------------------------- Full-charged=14.65 stop at 14.05 open battery tested at 15.13 pole at 14.65 Each-Cells read 5] [ 3.05 ] 4][ 3.01] 3][ 3.04] 2][ 3.00] 1][ 3.01]
Fully charged, you should read about 20.8v at the terminals where the tool plugs in. "Empty" is about 15v. If you measure the individual cells, Fully charged will settle to about 4.15v and "empty" is 3.0v. So it sounds like your pack is not charging correctly. I would try it in a different Ryobi charger first to make sure the charger itself isn't the problem. Then if you're sure it's this specific battery that is not charging, I'd assume something is wrong with the control board in it and that's not easy for me to help you diagnose online. Because the voltage reading will sag extra low while a tool is in use, they usually cut out around 2.5v so that the actual voltage after it sits for a few minutes is around 3v. The BMS won't let it go lower through the regular contacts on top.
