question on batteries

[G.]

I used to know battery technology, but it's been a while.

WTF is up with the nickle-metal hydride batts? I got them for my digital camera. They seem to go dead within a few days. Of NOT using them.

I know, Ni-Cad's self discharge in approx a month, the Ni-Mh are supposed to have the same burn rate (1-2% per day). My first Ni-Mh batts are a year and a half old, my newer ones are about 6 mos. old. Is this all that they last? Thought they lasted more than Ni-Cads. They've really tanked in the past few weeks. Old and new. They don't stay charged even for a week, more like 3 days. Unloaded.

I noticed on the charger instructions that if you have not used them in 2-3 months you should send them through multiple charge cycles (2-4). Done that.

Ni-Cad cells benefit from full discharge, then full charge (note I said CELLS, not batteries [a series of cells]). Ni-Mh too? I've even tried that, sort of.

Any idea on the life of them? Tips on how to rejuvenate them? Just buy new? Techie websites to explain all, Grasshopper? Need to know before I start to beat on the charger, trash the camera, kick the dog, etc.

They are Energizer batts.

Thanks.

[tllips]

I'm probably not much help, but I have heard (regarding Cell phones) that the Ni-MH do not like being fully discharged. I was told that it was better to "top it off" each night than to let it almost go dead before recharging.

Of course I was also told that this phone would work indoors too. (It's hit or miss)

[Hard Driver]

Ni-Mh "should" hold a charge longer than a couple of days. Whar device are you using these for? The advantage of Ni-Mh over Ni-Cd is the lack of a memory effect. The old deep discharge of Ni-Cd batteries is no longer required to Ni-Mh batteries. Although I have heard that when a Ni-Mh battery is brand new, it is best to "condition" them by having the first cycle be a complete charge - then full discharge - then a complete charge.

[KLang]

From consumer reports:

Rechargeable NiMH batteries have one major drawback: They lose 1 percent of their charge each day they are idle. That’s a good reason to keep a second set in a trickle charger or disposable batteries on hand.


Maybe there is something wrong with your charger?

[G.]

tllips, your phone DOES work inside, perfectly well. You cellular SERVICE (communication to and from the base station) is what is hit-or-miss.

HD, the intended device in a digital camera, but that doesn't appear to be the issue. The batteries, after charging do not hold a charge for more than a few days. I put them into the camera, turn it on, and nothing. If I pull them hot-out-of-the-charger (or a day or two after charging), they work.

They appear to lose more than a percent or two per day, when unused.

So, here's where I stand:
I don't know much about Ni-Mh technology. Maybe they wear out after a few month's use. Maybe they DO need full discharge every so often (seems to me they are kind of getting a full discharge by default :) ). Maybe a full discharge kills them, but the (wussy) "instructions" say that if they sit for a few months, give them a few charge cycles to help them recover. Tried that.

These are really my questions to you, my esteemed racing board net jockies.

If I am convinced that the batts should be good, then it's time to check the charger, check the camera for excessive turn-on current (camera needs GigaAmps, batts can only give milliAmps, battery sense ckt in camera says no dice, stays off), whatever.

I have not checked the voltage of the charger, batteries, no load tests on them, etc., etc. Lots of tinkering can ensue, or I could buy new batteries. But I'm a geek. Ain't gonna happen! :flame: :gomer:

[dando]

I'm not a battery expert by any mean, but I can relate my experiences with these batteries....are the batteries generic knock offs? If they are, you may have a bad set of batteries. I bought a couple of generic backups for my Canon S30, they do not last as long as the original. One of them only last for a few pics right out of the charger. These are special batteries designed for my camera. Or are you using standard battery size rechargeables from Energizer, etc.? With these, I have never had an issue with them losing much charge sitting idle after being charged. They might lose 1/3 to 1/2 charge while sitting for a month or more.

-Kevin

[G.]

Energizer, AA's.

[oddlycalm]

You either have a bad set of batteries G. or a charger that doesn't work right. I use Ni-Mh for everything from electronic mouse traps to portable music systems, cameras and breathing equipment. I buy them on eBay. The best ones I have found are labled DynaCharge and are made in Singapore and Nexcell has been good as well. Most of what is on the market, regardless of what the label says, are generic Chinese production. Some of the Chinese batteries are ok, but many are junk. If you're going to by the Chinese stuff don't pay up for some bogus brand, just buy the generic green case batteries. Ratings don't mean much either. I have 1800mAh batteries that far outperform 2500mAh Chinese stuff.

I've got nearly 5yrs of hard use on most of my batteries. I had to toss a few at the beginning but those that worked from day 1 still work. When I set up the wife to do the same for herself we had similar results. The DynaCharge and Nexcell stuff worked better so I just got her 25 of each.

I haven't had real good luck with US "branded" batteries, so I can't recommend them, particularly at the silly premium prices charged in stores. I pay right around $1 per AA and get the same or better service than from the $3 batteries with a US company stamped on the front and they are likely made in the same factory.

Any good Ni-Mh charger will have a discharge button or setting. Fully discharging the batteries periodically is a good thing. Some of the better chargers full discharge the battery every time they charge it. The closest charger I found to the one I use is here. I have no idea who the seller is, so I am not making any claims.
NiMH charger (http://cgi.ebay.com/Fast-Smart-Universal-Battery-Charger-for-All-Batteries_W0QQitemZ5726707819QQcategoryZ48618QQtcZ photoQQcmdZViewItem)

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