Li-Ion batteries

[gomi_otaku]

I was doing a search for some CR132 Li-Ion rechargeables, and noted that they are definitely not all the same. I have found anywhere from 2.7- 3.7V batteries, with anywhere from 700 to 1200 MAh ratings.
Now, I thought a CR132 was generally rated at 3V. If I were to use batteries with other ratings, I'm assuming I can get more power, or more time, out of them. Since I would be using them in an LED light, I don't think I can overdrive it with more power...so more than 3V probably isn't needed, but less might cause problems, especially as the battery nears the end of it's charge? So all things considered, what I should look at is the MAh rating so it lasts me longer on a charge, right? Please correct me if I am wrong.
This is probably way too much thought, considering these are going in backup lights....but if I ever needed it, I guess it would be important.
gomi_

 

[divinginn]

the higher the miliamps the longer the burn time.

 

[gomi_otaku]

That's what I inferred, thanks for the confirmation...but does it make any sense to get anything with a higher than 3v rating as well, since I am driving an LED?
gomi_

 

[jtivat]

That's what I inferred, thanks for the confirmation...but does it make any sense to get anything with a higher than 3v rating as well, since I am driving an LED?
gomi_

Without knowing how the light is being driven (with a voltage regulator or simple resistor) I would not go with 3.7 volt cells as you could fry the light. I also would not use rechargeable cells in a back up light especially Li ion they are very low in there ma's and not very reliable yet (at least the small 3volt cells).

 

[gomi_otaku]

I am looking for them for an OMS Vega light- which says that it uses "solid state LEDs". I don't want to have to buy new batteries every time I use this light- the idea of "how long did i let it burn for, how much time do I have left on this set of batteries" is not something I want to have to deal with. Looking at rechargeables, it seems like either they are overpowered 3.6-3.7V with higher mAh readings, or I can get 3v with anywhere as low as 600mAh. I found some with a 900mAh rating, that are claimed to have internal voltage regulators to prevent overcharging, overdischarge, and to operate at 3v. Taht would still give me over 2 hours on a charge, and I could recharge them rather than toss them with half a charge. As a backup light, not doing decompression cave or penetration dives, I think that is tolerable. My air will run out before my light does, even if I use it for the whole dive. And that would mean my can light would have failed on descent.
gomi_

 

[CompuDude]

The OMS Vega is supposed to use Lithium-Ion 3v c-cells. The manufacturer does not specify that rechargables can be used.

The general rule of thumb, however, is rechargables for your primary, and non-rechargables for the backups. You want a long shelf life... and you're not supposed to use your backups for anything other than a real emergency. Replace every 6 months, used or not.

 

[gomi_otaku]

Thanks CD. I guess $30 for four batteries that I will hopefully never have to use is too much when someone just mentioned that CR123s can be had for pretty damn cheap ($1 apeice for regular batteries, I wonder how much OMS is asking for their extra-special ones). I'll save my money.
gomi_

 

[Homunculus]

12 batteries for $21 at http://www.surefire.com (they make awsome land lights by the way).

 

[blahblahblah]

Primary CR123a batteries are 3v. RCR123 batteries come in 3.7v and 3.0v varieties. Each variety needs a different charger/charge rate.

If going into a backup light like the Vega, use primaries! These batteries have a 10 year shelf life. Another poster said the Vega uses "c-cells". This is incorrect, as it uses two primary CR123a batteries.

Surefire has top grade batteries. If you're willing to go with "no name" brand batteries, they can be as low as $1 each.

A good source for primaries is Battery Station.

 

[CompuDude]

Oops, you're right, I misspoke when I said C-cells (eyes skipped to the next line on the manuf page) http://www.omsdive.com/lights.html The thrust of my post was rechargables vs. non in your light, however, which was correct.