canon charger and battery questions

[felix21685]

hey guys i have just received some batteries from sterlingtek (nb2lh for rebel xt)

they are 1500 mah opposed to the canon's 700 mah batteries.
physically i can tell very little difference.

now..
what is the center contact used for ? i understand the positive and negative but what is the center contact for ? the little symbol looks like a T..

if i hook up a voltmeter to it what should i connect the T to ?

also-

does the canon charger have a charge limit. meaning will it not charge over a 700mah battery..is there a safety feature like that ?
in this case how do i get a full 1500 mah charge into these sterlingteks.

thanks for all your help

[lostdoggy]

I think the T stands for Temp. While charging Temp is very important especially when it is a smart fast charger. The charger will charge at full power till the temp rises to an unsafe level and then stop and start when temp drops to a safe level. Overheating while charging will destroy the battery. I also bought my extra batteries from Sterlingtek and they last way longer then the canon battery. It is especially nice when they last longer and cost less then half of the OEM.

One thing the last time I check sterlingtek the NB2 are 1800mAH for $12. I bought mine about a year ago and they were 1500mAH.

The charger charge base on temp and capacity. It'll charge till it can't. Less smart charger charge is base on time. Smart charger monitors the charge current and temp, when the Charging starts the charging current is high as it approaches charge completion the charge current tapper off till it become zero. smarter charger will go to trickle charge, meaning it provide a small current to maintain charge.

[felix21685]

i am assuming that the canon charger charges based on capacity not time..

[wilflee]

Lostdoggy is right. The center contact is for temperature sensor. Temperatur sensor is there to prevent the charger from charging too quickly and harming the battery.

The Canon charger is fine for charging. But if you're also looking for a charger to condition batteries, take a look at the Maha MH-C777 Plus II. http://www.mahaenergy.com/store/viewitem.asp?idproduct=185

It takes all kinds of dry rechargeables (NiCad, NiMH, LiION) and will discharge the battery if programmed to prevent memory effects. I use it to condition not only my camera batteries but also cell phone, TV remote control, flash, R/C cars etc.

[felix21685]

ive got conditioners and analyzers for nicd and nimh and a charger for Li-Ion and Lipoly i was just making sure that my new batteries are getting a full charge..

[tim]

Yep those batteries are fine, I have some, the Canon charger will charge them perfectly. Think of mah as the size of the gas tank on the car - more mah means the camera will run longer on a charge. As long as the voltage is the same it's fine. Don't worry about the voltage written on the battery, they're all the same even if they're marked slightly differently.

[lostdoggy]

i am assuming that the canon charger charges based on capacity not time..

Sorry. The Canon charger is a smat charger but not the smartest. It can't trickle charge nor does it provide a load to discharge the battery to condition it, so to say.

[felix21685]

ok thats fine..
tim- i know that the more amperage you have the longer the battery will last..
i was just wanting to make sure that the canon charger charges the 1500mah battery all the way since i have another lithium charger that stops charging after an hour so you dont overcharge.
you can set how many mah to charge it at but it has certain limitations.

[bolantej]

felix21685-

did you order them direct? if not, from where please. i am going to be getting some very soon. thanks!

[felix21685]

felix21685-

did you order them direct? if not, from where please. i am going to be getting some very soon. thanks!

hey i tried to order through pricegrabber.com..if you search for nb2lh and click on sterlingtek under the results under 3rd party they give them to you for 10.something dollars i got 2 of them and shipping was 6 something for a total of 26 for 2 shipped..

i used one of them today to upgrade my firmware..seems to work just fine.

[CGrindahl]

A couple of folks are talking about reconditioning batteries, which consists of draining them to empty. I recently read an article at a place called "BatteryUniversity" that said lithium-ion batteries are best NOT discharged. Here is a link for anyone interested in reading the article.

http://www.batteryuniversity.com/parttwo-34.htm

The problem with these batteries is that they simply get old and lose their capacity to hold a charge. With that understood it is clear there is no advantage in owning more batteries than will reasonably be used in current shooting. It is recommended that batteries not used be stored in the refrigerator to slow the aging process. Sooo, don't load you camera bag with batteries, even if they cost only $12. Better to introduce new batteries into your kit over time as you retire the older ones.

Thanks to the person who originally posted this article.

[bolantej]

well, i went ahead and ordered a few. at 1500mah, it should last quite some time.

[lostdoggy]

A couple of folks are talking about reconditioning batteries, which consists of draining them to empty. I recently read an article at a place called "BatteryUniversity" that said lithium-ion batteries are best NOT discharged. Here is a link for anyone interested in reading the article.

http://www.batteryuniversity.com/parttwo-34.htm

The problem with these batteries is that they simply get old and lose their capacity to hold a charge. With that understood it is clear there is no advantage in owning more batteries than will reasonably be used in current shooting. It is recommended that batteries not used be stored in the refrigerator to slow the aging process. Sooo, don't load you camera bag with batteries, even if they cost only $12. Better to introduce new batteries into your kit over time as you retire the older ones.

Thanks to the person who originally posted this article.

Considering that they cost less then half the price and twice the capacity, it is like buying one OEM but getting 4 batteries. I don't see what is wrong with that.

All batteries have a life cycle even if the manufacture don't list them. And Yes they will drain over time. Yes it will slow down the discharge rate of the batteries if kept very cold. But, when you out there shooting having that extra battery will give you that peace of mind. Its like life insurance, even though you're sure you won't die tomorrow it is nice to know that your family is taken care of today.