AA battery devices

[haino]

Hi

Can someone let me know if normal rechargeable batteries, NiCd or NiMH, be used in readers which run on AA batteries, for example ECTACO jetbooklite.

Thanks

[calvin-c]

Unless the manufacturer specifically recommends against them, then yes, they can be. They probably won't last as long (per charge) but the only difference, to the device, is the voltage. Different chemistry's produce slightly different voltages (don't remember offhand, but I believe an alkaline AA produces approx. 1.5v/battery while a NiCd produces 1.3v.) which is not, usually, a significant difference. But, as I said, specific manufacturers sometimes design their equipment with closer voltage tolerances-in which case they will specifically recommend against using the rechargeable batteries. RTFM-if it doesn't say you can't, then you can.

[Penforhire]

Says here, http://www.ectaco.com/main.jsp?do=pr...44&refid=29532 , "Ordinary rechargeable batteries, of course, can be used as well."

I assume they mean NiMH's.

[theducks]

Originally Posted by Penforhire

Says here, http://www.ectaco.com/main.jsp?do=pr...44&refid=29532 , "Ordinary rechargeable batteries, of course, can be used as well."

I assume they mean NiMH's.

NiNH have the 1.3V terminal voltage.

Be aware that all AA battery packages are not the same in mAH (milli-Ampere Hours). Do not mix capacities in the device, nor the charger. Battery failure may occur. Use only as sets of the same exact capacities.

[Penforhire]

Maybe fully charged but most of their discharge life is spent closer to 1.2 V. Sanyo claims their Eneloop's hold slightly higher voltage throughout discharge -- http://www.eneloop.info/home/perform...s/voltage.html

[drmaxx]

The voltage does not matter. Any device that can handle non-rechargeable batteries must be able to handle different voltages. Even alkalines don't stay 1.5 V for a long time (NiMH start at 1.4V). Using rechargeable NiMH or NiCd is just fine (There are also AA shaped Li-Ion batteries with 3.x V - these are NOT suitable).

There is an exception: Some gadgets rely on the voltage sag of alkaline batteries to be operated. These are typically high drain devices such as engines or flashlights. There you should NOT use rechargeable batteries, because they deliver too much power. But electronics is usually fine.

[Solitaire1]

Originally Posted by drmaxx

The voltage does not matter. Any device that can handle non-rechargeable batteries must be able to handle different voltages. Even alkalines don't stay 1.5 V for a long time (NiMH start at 1.4V). Using rechargeable NiMH or NiCd is just fine (There are also AA shaped Li-Ion batteries with 3.x V - these are NOT suitable).

There is an exception: Some gadgets rely on the voltage sag of alkaline batteries to be operated. These are typically high drain devices such as engines or flashlights. There you should NOT use rechargeable batteries, because they deliver too much power. But electronics is usually fine.

The only device I can remember were rechargeable batteries were not recommended were the Palm OS PDAs. The reason:

- They used powered memory that relied on power to maintain the PDA's memory. If the battery died, the data on the PDA was lost. When you remove the batteries to replace them, you had about 30 seconds to get the new batteries in before the data is lost.

- With alkalines, the battery drained at a steady rate which would give you time to replace them before the battery was completely dead. Also, the power gauge on the PDA was calibrated for alkaline batteries.

- With rechargables, the batteries had a flat discharge rate (a small drop at the beginning, an almost flat discharge rate for most of the battery's life, then a sudden drop at the end). At the end battery would die so quickly that you wouldn't have time to replace them before the PDA's contents would be lost.

I used rechargables with my Palm OS PDA. To avoid the above problems, I replaced the rechargeable batteries every other day regardless of how much/little charge they had. I never lost any data due to a dead battery since I replaced them long before they would go dead. Even with that inconvience, it was still much cheaper than replacing the AAA batteries at least once a week.

With most recent devices that use AA/AAA batteries that I've had, they have worked with rechargables. The only drawback is the shorter battery life, and the lower cost of the batteries are worth the tradeoff. To get around the shorter battery life, I carry an extra set of batteries.

I hope this helps.

[MikeB1972]

Hi haino

Recharchables work fine on the Jetbook Lite.
Due to the rapid drop off of recharchables though you need to swap them when the power meter drops to 2 bars as it doesn't give you much warning they are about to run out after this.

[Penforhire]

Solitaire, another example is a typical xenon camera flash unit (e.g. my Nikon SB-900). The charging rate, time needed between flashes, is greatly extended by switching from alkalines to NiMH. Nikon actually provides a a fifth-cell adapter to match 4-cell alkaline cycle times. Of course the annoyance then is having to charge five AA's as a set.

[HarryT]

Avoid Nicad batteries - they have all sorts of issues. NiMH is better in every way.

[haino]

Thanks all for your help. Most useful

Haino