Battery Help?!

[smokelight101]

First I'd like to wish everyone a happy holiday.
I sort of at a loss a have received a number of li-on batterys and a the top of each battery is what looks to be a tiny circuit board. I can no find any data sheet or any info. Attached is link if this could help. Any advice would be helpfull Thanks!!!

http://www.goldmine-elec-products.com/prodinfo.asp?number=G15693

Happy Hoildays
Tyler Berezowsky

 

[goom]

Almost certainly some circuitry to prevent over-discharging and/or over-charging. The former will permanently damage the battery, the latter can cause even more damage (explosion and/or fire)

 

[Dippy]

I'm not PC, so Happy Christmas, and shortly Happy New Year too.

Some batteries have things to store condition and charge/usage history too.
BB has done a lot of stuff on li-on and lipo, so he'll know.

 

[Andrew Cowan]

Those ebay lipos have a board that will cut off the battery if they are discharged too much. It will also cut off the battery if it is charged too much, but only if trickle charged. When fast charged, it can't cope.

A

 

[boriz]

Looks like a great site. Unfortunately they don’t ship to England!

 

[BeanieBots]

I have absolutely NO IDEA what circuitry is included with THOSE batteries.
However, when Li Ion are sold as PACKS, the circuitry is NORMALLY designed to prevent excessive discharge and a to a limited extent, excessive over-charge. In some cases (particularly laptop packs) the circuitry is designed to work SPECIFICALLY with the circuitry on the laptop charger.

If you don't KNOW what is included with a pack DON'T USE IT!
If you over discharge the pack, the circuitry is likely to switch off the output. SOMETIMES, this switch off can only be turned back on by by sending the correct I2C commands to the on-board CPU. Without the required data, that would render the pack useless.

When charging, the circuit MIGHT tell the charger what to do. Then again, it MIGHT NOT. If it does, will YOUR charger understand what it says? If it does not, will YOUR charger know when to stop?

Unlike NiCd, NiMh and Pb technologies, Li Ion cannot absorb excess charge.
Excess charge breaks down the internal chemicals into hydrogen and lithium. The hydrogen will make the pack expand until something breaks or splits. Then hydrogen and lithium leak out. The hydrogen, although an explosive gass, is not too dangerous. Pb batteries give off hydrogen & oxygen. A spark is required to ignite it. Unfortunately, lithium ignites on contact with air and/or WATER. NEVER TRY TO PUT OUT A LITHIUM FIRE WITH WATER.

Li Ion is NOT THE SAME as Li Poly.
Li Poly has a maximum terminal voltage of 4.3v
Li Ion has a maximum terminal voltage of 4.1v
Exceeding this by as little as 0.05v can cause an fiery EXPLOSION.
Most charges described as Lithium are for Poly NOT for Ion.
Use of a Poly charger WILL cause a fiery EXPLOSION.

UNLESS YOU KNOW WAHT YOU ARE DOING AVOID Li Ion technology.
Only use Li Poly with a PROPER (balancing) Li Poly charger.

STRONGLY advise all hobbiests to stick with NiCd or NiMh.
NEVER, NEVER, NEVER, leave a lithium battery charging unattended.

 

[papaof2]

If the packs are similar to those used in the Palm Zire, then the board contains *some* intelligence. The chargers provided with the original devices are simple two-wire wall-warts, so all the smarts have be in the device/battery. Some of these packs cannot be recharged in the device if the voltage drops too low (the device just beeps). I have recovered over-discharged packs by using a voltage regulated and current limited bench supply to get the battery voltage back above the shutoff point - not recommended for novices.

Be sure that you have a proper charger (voltage regulated & current limited, with a battery temperature monitor for over-temp shutdown) and that you do not charge the battery at more than the 10 hour rate (85ma). The 20 hour rate is safer (40ma).

Yes, there are fast chargers for some lithium batteries (the one hour charger for my cordless drill) but these are designed for the purpose batteries and smart chargers that can check the batteryt condition and monitor the battery temperature. The drill charger does a one minute test cycle before charging to determine the type of battery and its state of charge.

John

 

[smokelight101]

Thanks for all the help and the warnings. I think im in for a a bit of researching before i touch the batterys. After that I plan to but i container to hold them for protection and try to start charging them.
Thanks!!!
Tyler Berezowsky

 

[BeanieBots]

TIP:
If you going to make your own 'balance' connections, use JST connectors. Many other types have been used by various manufacturers but in recent years there has been a strong convergance towrds to JST. You will then be in a position to simply purchase (and/or be compatible with) most of the commercially available chargers/balancers. Be sure to use 4.1v and NOT the 4.3v used by Li Poly.

For safety, either get a proper charging bag (available from many RC outlets) or charge in an earthenware pot with a lid.

 

[hippy]

I plan to but i container to hold them for protection and try to start charging them.

There's a golden rule there - Don't use anything which turns an exploding battery into a fragmentation grenade or makes a disaster worse than it would be anyway should anything go wrong.

I know of a company which got told off by HSE for having LPG stored in a yard and were told they had to build a brick walled storage unit for them. On the second attempt they put mortar between the bricks ;-)

 

[Colinpc]

Depending on the capacity required, it is easy and cheap to get a Li-ion battery and charger. Just get an old mobile phone and connect to the battery contacts. The phone will charge without needing to be on. A small solar panel (6v) fed in via the charger connector and you have a complete power supply.

Fred

 

[retepsnikrep]

STRONGLY advise all hobbiests to stick with NiCd or NiMh. NEVER, NEVER, NEVER, leave a lithium battery charging unattended.

Beanie I know you mean well, but you are grossly overstating the dangers/problems.

Yes Lithium aren't perfect but with a decent charger/bms they are perfectly safe even for us hobbiests

They do not catch fire or explode at the drop of a hat when they go 50mv above the max. They fail if grossly abused and I mean grossly. I've seen some do it (Charged to double their terminal voltage etc) No bms etc!! They fail if over discharged but you just can't charge them up again, they don't burst into flames.

I leave my 144v 40ah Li-fepo4 pack on charge all the time unattended, it does have a BMS of course so it's attended by that

Nimh have a high self discharge rate and are quite difficult to charge correctly especially in strings of cells.

NiCd have the dreaded memory effect and high self discharge rate.

Lithium need the correct charger yes, and some protection, but they are much more effcient, and you get out virtually what you put in, even many weeks later. Try that with nimh

 

[BeanieBots]

Even you have stated "with the correct charger" several times in your post.
That's my point. Many hobbiests DON'T KNOW that they have specific charging requirements and think they can be treated just like any other type of re-chargeable battery.

It's one thing to learn the hard way that abuse kills the battery. It's another thing to learn about abuse that has more serious consequences.
It would be neglegent not to point this out.

12v Pb -> resistor -> NiMh/NiCd and away you go.
Try that with a lithium type and "away you go" except it's literally.

Lithium technology CANNOT absorb excess charge. It produces pure lithium+hydrogen. The hydrogen will vent and/or split the case and spill the lithium. Lithium ignites on contact with air.

Lithium is fine with the CORRECT charger, but NOT without.
Even with a "correct" charger, I'd not risk MY house with it.
Has your computer NEVER crashed?