NiMH Batteries

[doanster]

Is it normal for these batteries to lose their charge within about 2 weeks?
I would charge up a few batteries for my camera (with a set as spare), and after sitting on the shelf unused for a few weeks, they lose their charge. What's going on?

 

[soccerballtux]

They don't hold a charge very long, but that seems a bit short. As long as they still hold a decent charge, I woudln't worry about it. NiMH batteries do not form crystals when holding a charge for a long time (this is what kills NiCad, the crystals conduct and basically connect the + and - sides), so they should be fine for at least 5 years. Keep them in the charger till you need 'em.

 

[MWink]

Let me guess... They're Energizer 2500mAh with the letters "HR" stamped into the bottom. If so, they're known to have a ridiculously high self discharge rate. IMO they are completely useless. Get a better set of NIMH batteries and you won't have that problem.

 

[Ika]

Aren't NiMH batteries supposed to lose something like 4% of their charge per day?

if so, 2 weeks still short, but its foreseeable. especially if they're the batteries MWink stated.

 

[doanster]

Originally posted by: MWink
Let me guess... They're Energizer 2500mAh with the letters "HR" stamped into the bottom. If so, they're known to have a ridiculously high self discharge rate. IMO they are completely useless. Get a better set of NIMH batteries and you won't have that problem.

Hmm... they are the Energizer 2100mAh ones, not sure about the HR stamp.
No worries, I got myself a few new rechargeable Li-ion batteries + charger... hopefully they'll last a little longer 🙂

 

[JimPhelpsMI]

Hi, If you are using the Camera as a charge indicator and the Camera was not made for Rechargeable batteries then the Batts are probably still charged. All rechargables do lose a little charge rapidly, couple of days, after the charge. They start at about 1.3 volts and drop to about 1.2 volts. The camera was designed for Alkaline batts. They start at 1.5 volts and drop gradually with use. The camera is set to check for about 1.2 volts per cell so soon sees the NiMh batts as dead. NiMh hangs at about 1.2 volts per cell throughout their useful charge life so the camera says they are dead and shuts you down before the batts even get going. Some elcheapo cameras only indicate a low batt and do not shut down. They keep right on going with rechargeables.

Hope this helps a bit, Jim

 

[doanster]

Originally posted by: JimPhelpsMI
Hi, If you are using the Camera as a charge indicator and the Camera was not made for Rechargeable batteries then the Batts are probably still charged. All rechargables do lose a little charge rapidly, couple of days, after the charge. They start at about 1.3 volts and drop to about 1.2 volts. The camera was designed for Alkaline batts. They start at 1.5 volts and drop gradually with use. The camera is set to check for about 1.2 volts per cell so soon sees the NiMh batts as dead. NiMh hangs at about 1.2 volts per cell throughout their useful charge life so the camera says they are dead and shuts you down before the batts even get going. Some elcheapo cameras only indicate a low batt and do not shut down. They keep right on going with rechargeables.

Hope this helps a bit, Jim

Hmm... that makes sense.

But this camera was definitely designed for 1.2V rechargeable NiMH AAs or a single 3V lithium cell. It is barely functional with alkaline batteries :S

What's the average lifespan of NiMHs anyway? I had these for about a year and a half now, with very casual use.

 

[Skeeedunt]

Hmm... they are the Energizer 2100mAh ones, not sure about the HR stamp.
No worries, I got myself a few new rechargeable Li-ion batteries + charger... hopefully they'll last a little longer 🙂[/quote]

Where did you get Li-ion AA's? It seemed like that was a pretty limited market.

 

[0roo0roo]

just test how long they last after your camera claims they are low. it just maybe the camera being silly as said above. the discharge rate i remember seeing is about 1% or lower😛 and considering nimh aa powered cameras generally go on for hundreds of shots these days, losing a couple % isn't fatal! i've never whipped out my a610 and had it dead dead or anywhere near. even after a month or two..and i use whatever nimh is on sale😛

 

[JimPhelpsMI]

Hi, What Doan says makes sense, but I have seen Cameras that claim to work on Rechageables that do not!

Jim

 

[doanster]

Originally posted by: Skeeedunt
Hmm... they are the Energizer 2100mAh ones, not sure about the HR stamp.
No worries, I got myself a few new rechargeable Li-ion batteries + charger... hopefully they'll last a little longer 🙂

Where did you get Li-ion AA's? It seemed like that was a pretty limited market.[/quote]

Actually, they arn't li-ion AA's.
They are CRV3 Li-ion cells - fairly common for digital cameras.

 

[doanster]

Originally posted by: MWink
Let me guess... They're Energizer 2500mAh with the letters "HR" stamped into the bottom. If so, they're known to have a ridiculously high self discharge rate. IMO they are completely useless. Get a better set of NIMH batteries and you won't have that problem.

Whoa, nevermind. They ARE the 2500mAh ones with HR stamped on the bottom.
Thanks for pointing that out!