portable rechargeable battery pack for use with M100

[nameloc01]

I'm sure I could have something built..but I'm looking to see if there's anything I could just order as is without wasting too much time..

A rechargeable battery pack with a 3V output..preferably without a cheapo changeable tip/plug setup

Basically I just want an external battery pack to plug into my deck(s) when doing long periods of recording.

Any ideas?

Thanks

Jason

[Avrin]

Doesn't the M100 have its own external battery case? This should be enough for most recordings. Simultaneously using a fully charged gumstick inside the unit and a good fresh alkaline AA inside the connected battery case gives a really long operating time. Actually, longer than if you use them one after another. Synergy at its best.

[sfbp]

My belief (backed up by some very naive experiments) suggests to me that the external cell actually charges the internal one whilst connected. So don't put the battery case on with a discharged gumstick - better to run completely without the gumstick at all. However as you say the combination of the two appears to be more than the sum of the constituent parts.... sorta odd

[nameloc01]

Yes..I do usually use the dry battery dock. But I was just looking to get a backup power source to have for those special occasions..something like this:

http://www.digital-camera-battery.net/universal-battery.htm

Looks like it would work..

[Avrin]

My belief (backed up by some very naive experiments) suggests to me that the external cell actually charges the internal one whilst connected. So don't put the battery case on with a discharged gumstick - better to run completely without the gumstick at all.

Exactly. Both batteries should be full - a new alkaline AA and a fully charged gumstick. The idea of the prolonged operating mode with two batteries connected in parallel is based on different discharge patterns of an alkaline disposable and a Ni-MH rechargeable. It really involves the AA partially charging the gumstick at earlier stages, but after the AA is sufficiently depleted, the gumstick maintains the required voltage, while the AA gives out the remainder of its juice, which would not be used if the voltage dropped below the required limit. The actual process may be a little bit more complicated, but the main idea is as above. If you use two similar batteries (e.g., the gumstick and an AA Ni-MH rechargeable), their total operating time will be roughly the sum of their individual operating times (no synergy). Again, both should be fully charged.

And I would actually advise disconnecting the battery case (or removing the AA from it), when the unit is not in use, so as to avoid unneeded transfer of current and possible leakage of the AA.

The N10 with its Li-ion stick and an AA battery case operates differently. The batteries are not connected in parallel, and it has a voltage upconverter inside its battery case. When the internal battery is depleted, it switches to the case that provides 3.7V. Here I would recommend removing the battery from the case when not in use (disconnecting the case may not be sufficient to prevent leakage).

Yes..I do usually use the dry battery dock. But I was just looking to get a backup power source to have for those special occasions..something like this:

http://www.digital-camera-battery.net/universal-battery.htm

Looks like it would work..

Anything with a stable 3V output giving suffucient current (at least 1A) will work. But voltage stabilization must be good - minidisc units don't like voltage changes on their adapter inputs.

Edited August 28, 2009 by Avrin