RCR123 self discharge rate

[Learjet]

Greetings, I've bought my first CR123 light, all others before have been AA, AAA or D. In these lights I have used NIMH and am not at all happy with the self discharge rate where they go flat doing nothing. What is the self discharge rate with li-ion rcr123's like?

 

[barkingmad]

If you mean the self discharge rate of the NiMH batteries try Eneloop or Hybrio (and various other names) low self discharge batteries.

 

[bfg9000]

Li-ion cells have a far lower self discharge rate than NiMH and even about half that of NiCD (The typical NiMH is reputed to have about 50% higher self discharge than NiCD, so from these numbers you may infer Li-ion has roughly 1/3 the self discharge rate of NiMH). This of course assumes the NiMH cells are not defective.

Protected Li-ion cells tend to have slightly higher self discharge than unprotected cells, but usually not enough to be problematic.

The mentioned Eneloop cells also have such low self-discharge that it should rarely pose a problem in any AA and AAA devices you may still have.

 

[Learjet]

Thanks for that.

 

[DM51]

This 1/3 figure doesn't fit with my experience. My NiMHs discharge much more than 3x faster than my Li-Ions, which hold their charge pretty well.

 

[SilverFox]

Hello Learjet,

Here is a test I ran on an unprotected Li-Ion cell.

It ended up with about 95% of its initial capacity after a year in storage.

Protection circuits can accelerate the self discharge rate slightly.

The modern NiMh cells loose around 0.7% of their remaining capacity per day, and the Eneloop cells only loose around 0.04% of their remaining capacity per day. The BatteryUniversity information is correct for older cells, but there have been a lot of improvements in the last 5 years.

Unfortunately, there is a bad batch of NiMh 2500 mAh cells that end up with around a 7%, or higher, self discharge rate per day. Also, it seems that the very high capacity NiMh cells tend to have a higher self discharge rate.

With today's cells, I think that NiMh cells have slightly lower self discharge rates than NiCd cells. Of course, Li-Ion cells are way better at holding a charge.

Tom

 

[barkingmad]

So stick with Eneloop / Hybrio (LSD) NiMH or Lithium batteries! As I said earlier I find that high capacity NiMH batteries 'exaggerate' their true capacity and after only perhaps a week or two they will have lower capacity than the LSD type NiMH anyway...

 

[Learjet]

Yeah I bought quite a few Energiser 2500mah nimh cells a year or so back. They self discharge and go flat faster than tyres driving over police road spikes. :scowl: It's been getting on my goat. These Eneloop cells look like they may actually be useful.

Back to RCR123's Li-ion cells, that's great to hear about the low self discharge rate. How many years with occasional use can I expect to get from these cells before their usefulness is used up? Say with a recharge once or twice a month. That battery site said "[font=Verdana, Arial, Helvetica, sans-serif]The battery frequently fails after two or three years."[/font] Is this still the case?

 

[SilverFox]

Hello Barkingmad,

I just ran some comparisons and discovered...

Sanyo 2700 mAh cells and Sanyo Eneloop 2000 mAh low self discharge cells equal out in capacity after 53 days. Before then, the high capacity cells have the edge.

Now this comparison that the cells are left in storage and then used. What is not understood is what happens when we use them a little each day. Someday I'll check that out too.

Tom

 

[SilverFox]

Hello Learjet,

Li-Ion cells "rust" from the inside. Early cells were only good for around 3 years and it did not matter if you used them or not.

Current cells seem to be lasting longer, and we are discovering ways to store them properly. If you do everything wrong, your cells will most likely be dead after a couple of years. If you do everything right, you may still be using them 5 years from now.

Tom

 

[Learjet]

Thanks SilverFox. I guess eneloop (couldn't they find a better word for these things ;-) ) cells have not been around long enough to get an idea of how many years of use they will give.

Apart from the very long shelf life of lithiums eneloop cells look like they should replace all nimh, nicad and carbon non recharge batteries. They sound wonderful, yet I see none in stores over here, only on internet. Not that internet shopping is a problem anymore.

 

[digitor]

Hi Learjet,

You can get Eneloops from **** Smith (if you want to pay a lot) or mail order from A&M Enterprises http://amenterprises.com.au/ for a good price. I first bought 4 from DSE to evaluate them, then got some 8-packs from A&M.

Cheers

 

[Learjet]

Thanks digitor. I've bookmarked the page.

 

[wptski]

Geez, I was going to start a new thread, no need!

I bought a spare extended Li-Ion battery pack for my HP 720 Jornada handheld PC "long" before joining this forum, so that's been more than a few years! It's been in my closet "somewhere" ever since. Every time I'd think about looking for it, one look in there, I'd say, not today!!

I figured that by now, it would be a hockey puck which I'm sure I paid well over $100 for. I couldn't believe my DMM when it showed 7.36V for the 7.2V 4.5Ah pack!! I put it on the stock HP charger and I'm using it right now, although I'm unsure of how long it'll last. Only time will tell but so far it hasn't dropped off full yet!! I've had protected CR123 die in lights unused and on the shelf.

 

[Vikas Sontakke]

I have a cellphone which was last charged sometimes in year 2002. It still turns on. I have often used the list of phone numbers from it.

On the other hand, every laptop that I had misfortune of working with, has lasted no more than 12~13 months before not holding any charge.

- Vikas