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Where and how to obtain high power Lithium batteries?

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Toe Cutter

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I was thinking of using rechargeable lithium batteries for a project. I might make a pack of 10 cells at about >= 6 Ah. I would also like moderately high discharge currents, like 3 amps.

But finding lithium cells seems very difficult. Distributers, like Digikey, only carry Lithium button cells and camera batteries. Batteries like SLA, NiCd etc are commodity, but finding general purpose lithium batteries that could replace SLA/NiCd etc seems more difficult. Am I looking in the wrong places?

Right now I am just trying to look around and see what is available and at what prices. For example, I found a Li-ion cell, the Saft VL 6A. This is similar to what I am looking for. Interestingly, this battery has massive discharge ability, 100s of amps.

Where could I find and buy higher power and higher capacity Lithium batteries? Thanks.
 
Lithium Polymer or Lithium Ferrite is what you want (LiPo or LiFe). The same kindn used to power model airplanes.
 
All the manufacturers I've looked into have a policy of selling cells only to certified battery pack builders. Given the recalls and fire possibilities, I can't blame them. And those packs were mfgr authorized in design and build. Open sales has a serious liability exposure.

I've been taking apart laptop packs to find and use the good ones. But, I'm not doing high charge/discharge with them. They seem to make a great standby source for low current duty. <<<)))
 
My local hobby store sells thousands of Li-Po (lightweight Lithium-Polymer) batteries for model airplanes. They range from 3.7V/70mAh to many volts at many mA hours. Go to www.horizonhobby.com and click on batteries.

A Chinese hobby website sells Li-Po batteries at a very low price. Shipping costs a little more than the cost of their garbage batteries. My friend gave me a cheap Chinese Li-Po battery to try and it has no power and runs for a very short time.

The electronic motor speed controller circuit in many model airplanes and helicopters can handle 50A of current. Then the battery can supply 50A or more of current.
 
if one can carefully manage without blasting their faces, we can salvage good cells for lab use from many old laptop batteries Of course one has to find an honorable way to charge them.
once we can manage these aspects,
perhaps the cells cost is no more an issue, rather they are free.
 
**broken link removed**

Check more hobby sites, that's just one I found quickly.

mvs sarma you'll be hard pressed to find a laptop battery that large 10c 6000mah is huge, it's hard to find even for RC uses. Good thing is the current discharge the poster wants is absolute nothing, 3amps from a 6000mah battery is only 1/2C RC Lithium packs are typically rated for 10-20C continuous with higher peak discharge rates.

Make sure you buy an appropriate charger for the pack, charging that many cells requires some moderately sophisticated cell balancing, you'll notice the pack in the link above has a large header, that's the charger connector, each cell has to be be charged and monitored independently. Try to do this yourself without knowing what you're doing and a large fireball where you battery used to be is the likely outcome.
 
I've recently completed a project where I wanted to supply a marine GPS receiver from a portable battery. I used 3 LI-Ion cells in series, each 1.8 Ah. I couldn't find a good way of charging them in series, as none of the charging ICs seem to have cell balancing.

I used a relay to put them in series to run the GPS, and then in parallel (but each with its own charging IC) to charge when a 12 V supply was present. It is a bit of a roundabout thing to, as there is a buck regulator to drop to 5 V, that is used to charge to 4.2 V, and then 12 ish volts is obtained with them in series. However, it works.

I don't know how large packs are normally charged when in series, but some way of balancing ( or even just limiting at 4.2 V on every cell ) would seem to be vital.
 
Thanks all for the replies. I didn't think to look at the RC hobby shops. Last time I used a remote control car it was with 'C' cell alkalines. From the RC web sites, it looks like what I want would cost $300-400. Too bad this tech is still so expensive. I would have thought the price would have come down with the huge portable electronics industry. I could probably get the same voltage and capacity with SLA for about $80 (and more mass and volume I bet). I was hoping it would be possible to buy the bare cells for a lower cost then a pre-assembled pack. This would involve adding my own charging/protection circuits, but I don't mind the added challenge so much.

One poster mentioned battery cell manufacturers are worried about liability. Its a shame these high capacity, high power batteries are not more available. I think there would be many people interested in using them for electric cars, motor bikes, UPS, etc.
 
Just out of interest I've heard it said that a fully-charged laptop battery has the same stored energy as a hand grenade!
 
Wherever you heard that it is totally incorrect. The explosive potential of a hand grenade is at least an order of magnitude or more higher than the energy density of a lithium cell. Lithiums when over charged abusively exhibit thermal runaway, they burst into flames, it's almost unheard of them exploding, and if they did, it'd be a fraction of what a hand grenade could do.
 
Wherever you heard that it is totally incorrect. The explosive potential of a hand grenade is at least an order of magnitude or more higher than the energy density of a lithium cell. Lithiums when over charged abusively exhibit thermal runaway, they burst into flames, it's almost unheard of them exploding, and if they did, it'd be a fraction of what a hand grenade could do.

In fact everything I read says that modern lithium batteries are indeed approaching the energy density of a hand grenade. The difference is how fast the energy is released.
 
Gobbledok, you might want to look at the math again. It might surpase the energy density of a grenade, but only about 1-2 ounces of a grenade is the actual explosive, comparing active ingredients and lithium chemistry isn't even close to a common explosives, let alone modern high energy explosives. Compare apples to apples before you make such a misleading statement. Science doesn't allow for assumption only propositions and in this case doesn't hold even a drop of water. I'm not trying to be offensive in my statements although they may appear harsh such misleading statements are the worst affront to the scientific method and a rational mind.
 
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