plz help. Charging my canon battery... thanks

[noamkrief]

Hi everyone.
My problem is that i have a S110 but no charger. And sorry I'm cheap, but i'm not about to buy a charger for 40 bucks...
Is there a way to hotwire a charger?

The battery itself is 3.7v and 680mA

The camera says 4.3v and no indication of the amps...

I'm not sure, but i think that the original charger was 4.3v and 1.5a (or 0.5a)

What would happen if i tried charging with a 4.2v 400mA charger?
How about with a 4.2v 800mA charger?

How come the stock charger is 4.3v and the battery is 3.7?

Also - the battery has 3 connection... +, - and a middle one which is ground right? (do i even need to deal with the middle one when I'm charging?)

Thanks very much everyone. And sorry if these are stupid questions i'm asking here.
thanks again.
Noam

[roine]

Hello

NiJo battery are very, very sensive to overheating.

Roine

[oldlincoln]

If the price of a charger is too much, just sell the camera to me for $30!
Seriously, the battery you have is a NB-1LH. It is 3.7V 680 Mah (not Ma) Lithium-Ion (I don't know what a "NiJo battery" is). You should not try to rig a charger this battery. I now how and I wouldn't bother. Just buy a off brand charger from one of the online battery places for 20 or 30 bucks.

[robertwgross]

It is quite common for a lithium battery pack to have a rating like 3.7 volts 680 milliampere hours. It is quite common for a charger to output a voltage slightly more than 3.7 in order to effectively charge the battery pack. So, a charger with 4.3 volts seems normal. If the charger has a slightly low amperage rating, then that is fine, since most chargers charge up the battery pack at a slower rate than what the battery will discharge. If the charger were much higher than 4.3 volts, then it might "toast" the battery pack and cause it to age rapidly.

---Bob Gross---

[Dans_D60]

A high-quality battery charger will current limit at different phases of the charge cycle as the battery reaches the target voltage. The “third” wire you see is most likely a sensing voltage or a sensing temperature wire. Most modern chargers have integrated circuit components that can “read” either a voltage drop or temperature sensing feedback loop as part of the regulation cycle. A good Li-ion or NiH charger will start by a trickle phase until the current draw increases to a set constant. During phase two the charger will raise the voltage to about 10% above the battery rated voltage (maybe the 4.3 volts vs. 3.7 volts issue). The charging phases are completed when the battery can maintain a voltage about 5% above the battery rated voltage at no more than a constant 5 milliamp draw. Phase two may require more current than the battery ratings. Thus a 600 milliamp hour battery may require a full ampere during phase two. The absolute worst thing is overcharging. So, if the battery charger is not designed for the battery being charged, it may be possible to overcharge during phase three and reduce the life or even damage the battery. Oh … don’t forget the “h”. Batteries are rated in ampere “hours” or milliamp hours. A Canon BP-511 is rated at 1100 mAh or the ability to deliver 1100 milliamps for one hour … or 550 milliamps for two hours .. and so on. Break down and spend the $40.
Dan
http://www.pettusphoto.com