NiMH battery expectations
 

Including some lights for bikes, like most people, I have many things around the house that use AA batteries. I invested in some Energizer NiMH rechargables which seemed to work well for awhile but now they either don't hold a charge or the are very short lived. I have one device that seems to drain the rechargables but the non-rechargables hold up as expected. (I first thought there was a short in this device.) The batteries haven't been recharged more than 4-6 times.

Is this to be expected?
Should I change brands?
Perhaps I over drain or not drain enough before recharging.
Maybe my charger (bought at WalMart) is not of a high enough quality.

Any ideas or input would be appreciated.

read up, my friend

http://batteryuniversity.com/index.htm

properly used, those Nimh's should last a looong time.
cheers

I've had horrible luck with Energizers too. All other brands have been okay for me though.

NiMH batteries should not crap out after 4-6 charges. I've gotten hundreds of charge/recharge cycles out of mine. I wouldn't sweat the memory since that isn't a major issue with NiMH. Powerex and Sanyo NiMH batteries are both good in my experience. I get almost the same runtime from 2500 mah Powerex NiMH AA batteries as alkaline and I can recharge them hundreds of times. Getting a better charger is a good investment since a good charger can prolong the lifespan of rechargeable batteries significantly. Thomas Distributing is a good battery website.

Which device drains the rechargeables but the non-rechargeables hold up as expected? How often is it used? Battery capacity? When were they purchased? Charger model?

Describe exactly the 4-6 times the batteries were used: Initially charged or used right out of the box, usage detail-devices and time period, recharge procedure, time in charger, etc. Maybe something will jump out.

From what you are describing, keeping in mind I am not an expert, but I will guess that you have a rapid charger and have left the batteries on the charger for a long time and they have developed memory(yes nimh's develop memory it just takes longer than nicads and they require less maintenance to prevent it).

I have also seen some references to troubles with some Energizers, but praise for others.

You can probably refresh them by using a LaCrosse or Maha charger/analyzer since they have been used so few times. Thomas Distributing or Amazon is a good source.

Consulting batteryuniversity.com has given me much knowledge about batteries and dispelled many myths.

Give it another try, charge them up, then when the NiMH's crap out in your device, get yourself a voltmeter, and look for the ONE bad battery which probably is showing 0 volts contribution and is dragging the others down with it. It's quite common.

Wow, my Energize 2500mahs are better than any I've ever used.

Energizer will give you a coupon for new batteries if some of them are bad. Just go to their website and tell them that you received some bad batteries.

http://www.energizer.com/contact/default.asp

Excellent point IMHO. I recently acquired a more sophisticated LaCrosse battery charger. I can use the discharge mode to reduce memory effect and determine the capacity of each battery. I am then pairing the batteries according to capacity to maximize the higher capacity ones and singling out the slightly less capacity ones for single battery applications. So far there have not been any with significant enough reduction to refresh, for which I have been pleasantly survived given my well intended but misinformed knowledge of battery maintenance. But the discharge and refresh feature can cure this in most cases.

But by all means because of the few cycles these batteries have been through do not hesitate to request replacements for weak cells.