Questions about LP-E10 Batteries---I already Searched

I spent some time poking around in the battery sticky at the top, but it started in 2005 and 45 pages is a bit overwhelming.

I have a multi-meter, in fact several of them, and use them all the time.

If I want to test my Canon LP-E10 batteries with the multi-tester, I see four contacts on the battery; the chargers all have four contacts; as best I can see down in there, the camera only has three contacts; which of the four contacts do I put my test probes on ?

I reckon these are DC batteries; why so many contacts ?


Now, about the original equipment chargers that came new with our Canon T3 cameras:

Are these "smart" chargers; in that, do they quit charging when the battery is full ?

There are two lights, one amber, one green; I am assuming Green means Full/Finished; should I remove the battery as soon as possible after the Green light comes on?

What about those times when I get side-tracked and the battery remains in the charger over-night or maybe even a couple days; is that harmful to the battery ?

I have many more questions, but that is enough for starters.

Thanks for reading and all help is appreciated.

According to general info about lithium batteries, the Li-ion batteries (that are used in mobile phones) have 3 three terminals, namely the positive terminal, the negative terminal and the third terminal is connected to the internal thermistor, thus enabling the charger to measure the battery temperature. Basically required to charge the battery safely.
On the Canon battery there is a B and a D terminal... no idea what is terminal D and B specifically are for, One guess for Current sensor or temperature sensor,

The charger will stop charging when it determines the battery is fully charged. It would be dangerous if it did not stop.
Most Canon camera Lithium batteries have 2 cells (1D series have 3 cells).
4 terminals would be: +,-, balance and temp.
Balance terminal required to safely charge 2 cells.

Wilt wrote in post #18743014
According to general info about lithium batteries, the Li-ion batteries (that are used in mobile phones) have 3 three terminals, namely the positive terminal, the negative terminal and the third terminal is connected to the internal thermistor, thus enabling the charger to measure the battery temperature. Basically required to charge the battery safely.
On the Canon battery there is a B and a D terminal... no idea what is terminal D and B specifically are for, One guess for Current sensor or temperature sensor,

Choderboy wrote in post #18743021
The charger will stop charging when it determines the battery is fully charged. It would be dangerous if it did not stop.
Most Canon camera Lithium batteries have 2 cells (1D series have 3 cells).
4 terminals would be: +,-, balance and temp.
Balance terminal required to safely charge 2 cells.

Thanks to you both.
Well, I got the + and - terminals identified; it just so happens that they were actually marked on a couple of our generic no-name batteries.
I can only speak for the LP-E10:
With the battery standing on it's end, terminals facing up, --- I will call the terminal closest to the edge Terminal-1; the terminal closest to the center Terminal-4.
Terminal-1 and Terminal-3 must be the balance and temp terminals.
Terminal-2 is + (Positive)
Terminal-4 is - (Negative)


Now, another question:
Concerning two 1850-mah of unknown heritage and probably of differing ages; the same charger was used on both batteries AT DIFFERENT TIMES:
One battery was charged on 15-June-2018 and has been riding around in it's holster ever since; tested today = 8.28v
The other battery was just removed from the charger = 8.02v >>> On EDIT: I just put this battery back in the charger and instead of gaining, it lost..... 7.80v I guess it is on it's way out.

The battery with a five-month-old charge reads more voltage than the one fresh out of the charger; is such to be expected; or, is the 8.02v battery only capable of taking an 8.02v charge and indicative of impending demise ?

BuckSkin wrote in post #18743005
If I want to test my Canon LP-E10 batteries with the multi-tester, I see four contacts on the battery; the chargers all have four contacts; as best I can see down in there, the camera only has three contacts; which of the four contacts do I put my test probes on?

Some of the 3rd party batteries indicate the terminals that should yield the open circuit voltage of the battery. They are marked "+" and "-" in the image below.

8.02v off the charger is indication of a problem. 4.1v per cell is 90% charge.

8.28v after months is very good.

8.4v straight off the charger and around 8.3v 24 hours later is about normal.

John from PA wrote in post #18743111
Some of the 3rd party batteries indicate the terminals that should yield the open circuit voltage of the battery. They are marked "+" and "-" in the image below.

Thanks for confirming my findings; we were typing at the same time; the picture better shows what I tried to explain.


Concerning my above inquiry about the differing charge levels between the two batteries described, I have since tested two other batteries that were charged today:

Original Canon identified as September 2013 860-mah = 8.29v

Another generic of unknown heritage = 8.37v

I also went ahead and topped-off the 8.28v battery in my previous post and it now tests fully charged at 8.37; that's not bad to only lose .09v over a period of five months.

I did a bit of purchase-history research and, with the exception of a pair of easily identifiable 2000-mah Halcyon (which I can't test right now on account of the wife using them today, all of our batteries are at least as old as November 2015 with some being purchased as long ago as November 2013.

I should keep a better account of the when/where/why of our camera batteries and intend to start a record today.

I did try to practice a rotation regimen for a few years, such that each battery took it's turn in order, but it got side-tracked this summer.

For those of you who do keep such an account of things, what is the average life expectancy of these batteries before they quit holding charge ?

Choderboy wrote in post #18743123
8.02v off the charger is indication of a problem. 4.1v per cell is 90% charge.

8.28v after months is very good.

8.4v straight off the charger and around 8.3v 24 hours later is about normal.

Thank you; that is very helpful.

https://batteryunivers​ity.com …g_lithium_based​_batteries might be worth a read.

John from PA wrote in post #18743248
https://batteryunivers​ity.com …g_lithium_based​_batteries might be worth a read.

Thank you, I will read it.

It's not worth worrying about batteries. My 1D4 battery is still going strong (manufactured early 2010).
Just use them. If they die early replace and continue.

If I wanted to treat my battery well I would not use it. I would avoid storing it fully charged. I would not even fully charge.
(Most Lithium cells life can be doubled by only charging to 90%.) I would keep them away from high temperatures.

It's much easier to just forget about them and use them.

Choderboy wrote in post #18743498
It's not worth worrying about batteries.
Just use them. If they die early replace and continue.
It's much easier to just forget about them and use them.

That is some very good advice.

I often am being run over by camels while straining at gnats.

Once a person has been poverty-stricken for several years, it is hard to shake off the habit of being overly frugal and trying to wring the last bit of usefulness out of everything.