Ryobi Lithium Batteries 2 for 1

[pauls_workshop]

Get that P113 RMA'd!

See here: http://www.garagejournal.com/forum/showthread.php?t=223106

And here: http://www.ryobitools.com/safety_notice

As for the P104, I'm going to bet you won't see that same behavior - I don't see it on the P102, just the P107 and P108.

Yes, I also confirmed that, my older full size lithiums and ni cads both show the 19-20 volts all the time with the fresh charge, whether run or not. Only these new lithium plus are the weird ones, which is what messed up my normally forthwright and sound mind pretty darned good there for ahwile! Glad Kyrhri set me straight fast! Thanks again K, you are awesome!

Now who can tell us all WHY these new ones act like this? What is the reason? - Paul

 

[djjsr]

Get that P113 RMA'd!

Thanks for the reminder. It's on my 'to do' list. I've got 2 of them. I don't leave them unattended since I heard of the problem. What do they send you as a replacement?

 

[pauls_workshop]

Thanks for the reminder. It's on my 'to do' list. I've got 2 of them. I don't leave them unattended since I heard of the problem. What do they send you as a replacement?

Someone posted they got a new yellow P117 one. Those should be good ones, fast charge type. I like the black P118 slow chargers because seems to be real good for the batteries life. I gotta send mine in now too. - Paul

 

[mark5767]

Looking at these batteries another thing I noticed with some of the smaller 4V Ryobis is there is warning on the charger if the battery is too hot or cold. My garage is only part-time heated and it's been well below zero here so that could be affecting some of my battery performance possibly as well.

Historically I just left my batteries in the garage most of the time so I wonder if that has led to some premature decline in the past.

I think I will try to keep my batteries in the basement workshop during the winter from now on. I wonder if a discharged Li-Ion will freeze in extremely cold temps like a lead-acid and be damaged?

Anyway, I guess it's easy enough to keep them inside during the winter, I just never thought they were susceptible to freezing, but it looks like they have a temp range they need to be in to operate effectively.

 

[beamrider]

Best storage temp for a Li-on cell is ~65°F, and I've found it doesn't take too many times leaving one out in the freezing cold for a night, to wreck the battery. Plus, if you're not going to be using a cell for a while, don't store it fully charged. They like to be stored around 60% charge.

 

[kythri]

So, emailed Ryobi and got a confirmation/non-answer:

My question:

12/26/13 17:07: I'm curious why, when testing the voltage on a freshly charged P107/P108 battery, the voltage reads 8.2V, but when testing after having applied load (such as running a drill) on the battery, it then reads it's proper 20.7V.

The behavior is not present on the P100 NiCd or P102/P104 Lithium batteries, just the P107/P108.

Curious of the technical reason for this, and what is different between the P102/P104 and P107/P108.

Thank you!

Their reply:

12/27/13 10:22: This is the design of the circuit on the battery. Unfortunately there is no information that can be given as to why the items were designed this way.

Best regards,

Tim Beasley
One World Technologies, Inc.

 

[91bronc300]

My guess is maybe some type of cell isolation or something inside the battery to prevent an internal or external dead short from creating a thermal runaway inside the battery and causing an explosion.


Look up 'Lithium battery thermal runaway'.

 

[mark5767]

Best storage temp for a Li-on cell is ~65°F, and I've found it doesn't take too many times leaving one out in the freezing cold for a night, to wreck the battery. Plus, if you're not going to be using a cell for a while, don't store it fully charged. They like to be stored around 60% charge.

Thanks, reading just a bit more on this it appears these batteries are reasonably durable so if I leave one outside in the car it should be ok. This actually matters quite a bit to me because the more Li-Ion tools I acquire the higher probability they will need to survive in cold temps. I take tools with me in the winter and constantly assuring them an ideal storge temp is just not realistic.

It appears heat is more of an enemy to these batteries than cold. Leaving your fully charged batteries (maybe even on a car charger) in the hot summer sun inside a vehicle sounds like it may do quite a bit more damage than leaving in the cold.

Also, memory is supposedly not an issue with these batteries. As you said leaving them roughly half charged is probably best for storage.

Interesting also is that "back up" batteries in this style might not always offer a huge advantage? Apparently time kills the batteries more than anything, so an improperly stored back up might die sooner than a battery you are using.

Well, they are not cheap and they sure can be handy, so proper care is probably something worth talking about! Good thread, thanks for sharing!

 

[beamrider]

Yeah, there's no "memory effect" per se with Li-on cells, at least not the way most people use the term (from the NiCd days). From what I've read, storing a Li-On cell fully charged will kill about 40% of its capacity over the life of the battery. If I know I'm not going to be using a cell for a few months, I'll run it dead, then charge it for slightly over half the time the charger is rated for (i.e 1 hour charger, I'll charge it for ~35 minutes), and keep it in my basement.

The 18650's and 18350's that most power tool packs are constructed from, are also what is used to build laptop battery packs, and also what I use to run my various e-cig mods, so I do a lot of charging/maintaining/storing, and when I started using e-cigs, I figured I might as well do some research on the subject.