Does anyone know what type of batteries are in these packs and if they are able to be replaced with new cells?
One of my older, lower capacity batteries uses Samsung INR1850-13_ in a 5s configuration - I don’t remember the last character but it was a letter. It’s rated for 1300mah. I haven’t disassembled any of the newer higher capacity ones, but they are rated for 4ah. In a 5s2p, that would require a 2000mah battery.
Replacement batteries would need to be meant for high current draw.
I agree - I think the Samsung were rated for 18 amps continuous.
The new Bosch 1/2” 18V Lithium drill i have has what looks like Samsung 25Rs to supply the high current loads of the drill motor.
LS Chinese
Samsung 1300 mAh
LG 1300 mAh
Sanyo 1500 mAh
Best bang for the buck would be Samsung 20R.
Higher capacity (a little more $ ) options would be LG HE2 or Samsung 25R.
Like Helios said, you must use high drain IMR type batteries. All of the cells above can take 20A continuous no problem. For example, Panasonic 3400 or Sanyo 2600 WILL NOT work for this application.
http://www.homedepot.com/p/Ryobi-18-Volt-Lithium-Battery-2-Pack-P122/204321540
For $99 you get 2, 4Ah battery packs ready to go. Each pack contains 10 Samsung 20R’s. That works out to $5 per cell, you can’t even buy those cells loose for anywhere near that.
I agree on the value of the packs, but you can get them for <$5. (see link above when qty is 3 or more)
That is a great deal - usually a single battery costs this much. They’ve been running this promotion for a several months now. I bought that pack several months ago at $99 and I feel it was well worth it.
It seems like I've gotten all of these from the ryobi packs too .(not the sanyos )....and add to them Moli's....My purple china cells are the same /but different .Defiantly older than yours .
Seems ryobi uses whatevers handy at the time .
If you can get the one with samsungs you'll be a happy camper :)
I have 4 more Ryobi drill packs to tear apart from the recycling bin.
I'm wondering why it's so commonly found in these bins ...Seems like I've ripped open 4 or 5 and have another 4 here ....I'm actually waiting till I get the right bit for the screwdriver .The way I've been getting them open is kind of crazy ... Since I have so many to do i'll wait for the right tool
If you dont have t15 security you can use regular t15 and just hit the center pin with a drill for 1 sec and it will break off. Also I have had a pack with moli 18650e cells.
I have been meaning to rebuild my pack but can’t tin the samsung 18650 replacement(doesn’t stick) . Any suggestion ?
Flux? Lots of flux.
Are you soldering directly to the 18650s or to solder tabs? You want to be very fast if its directly on an 18650. Heat can damage li-ions, potentially make them dangerous.
Even with lots of flux the solder isnt sticking to the 18650 (like the ones linked above which dont have solder tabs), tinning the tabs from the pack is no problem but getting the tabs to solder to the cells isnt working for me (samsungs seem especially resistant to soldering, tried tinning some old recycle cells and no issue).
A lot of what kind of flux?
You don't need a lot, you just need a hot iron. Wipe the cell with acetone, one drop of flux, load a dollop of solder onto the tip, wait a few seconds for the iron to recover from melting the solder, then lower the iron until the dollop of solder (but not the tip) contacts the cell. If you've done everything right up until then, about the time you count to 'one-' the solder will flow off the tip and onto the cell.
I wasn't able to do it properly until I got a real soldering rig. I set the temp to 820-830*F, and watch the readout to let me know when it's hot enough to proceed.
I have just noticed that the Ryobis do not balance charge!
The on board circuit on each pack merely checks the voltage of each cell as the pack discharges. When the first cell in as soon as any cell in the pack falls below approx 2.8V it shuts down.
When the pack is charging, as soon as any one cell rises to about 4.23V, charging stops. So what happens is that the laggards never get fully charged
Of course what happens over a period of use is that 1 or more cells fall behind and the whole pack seems to loose capacity, so it is discarded. Periodically, what should be done is to take apart your pack and check the cells and manually balance charge the lowest ones up to the others. as long as there is nothing wrong with the cells in question, the run time of the pack can be greatly increased.
Also it seems that if any one cell falls below a certain voltage, perhaps around 2.5V, the charger will not recognize the pack and fail to charge it. This I assume for safety’s sake. Ryobi does not seem brick the pack when this happens, but I suspect Makita and Ridgid does after a pack is inserted into a charger a certain number of times in that state (for safety’s sake)
I would not recommend anyone trying to repair these packs as 5 or 10 cell IMR packs contain a LOT of energy. If something were to go wrong……
Wow, Moli’s too? Never seen one in a Ryobi, these things are turning out to be collectible!
I’ll trade you a Sanyo and an SK68 for a Moli. 
The only Moli’s I have ever seen were in this 18V Ridgid and this 12V Milwakee.
