[unclesomebody]

I've got a little project in mind but it requires some knowledge that I don't have (or can't find). Basically, I would like to find a way to replace a 10 D Cell battery set up with a single rechargeable unit of similar (if not smaller) size. Does anyone have any info on such a thing, or even some links to related material so I can figure out how I'm going to do it. I imagine there must be some sort of rechargeable battery that output the same voltage/current as 10 D cells in a smaller package which is also rechargeable... it's 2008 after all!

Thanks

[dave]

I assume theres a particular reason you don't want to use 10 D rechargables?

If the D cells fit into something and you can get something of the right voltage/current but its a differnt size/shape then you can make a dummy battery with bit of wooden dowel and wire the new battery into this.

P.S. on the voltage front, you probably only need to be near enough rather than absolutley bang on. most rechargeables have a lower voltage than their equivalent alkalines anyway. for example AA is 1.5v but a NiMh AA rechargeable is often only 1.25v.

[unclesomebody]

I don't think 10 D rechargeables is the most efficient or elegant solution. I'm sure there will be a way of achieving a longer battery life with a smaller rechargeable unit. The size/shape isn't hugely important. It doesn't have to fit in the space of 10 d cells as I could make some modifications, but it would be nice if it did!

[Drew]

Forgive meif I'm wrong, but isn't the voltage output of a D-cell, the same as it is from an AA or even an AAA cell? 10 x AAA batteries is a much smaller, neater package, but won't last quite as long as D cells.

Or is there some difference in the Wattage?


In fact, if the AAA (1.2V) rechargeables are ok then this looks like a good one. 1100mAh !

[Johnny Brown]

Model aircraft types all uses packs of rechargeables like this. Similarly last generation big camera batteries usually consisted of smaller ones built inot a pack of the required size and voltage. I'm sure if you search a few forums you could find some info on building them.

[dobbin]

Are you making a propeller Keith?

[Jaspersharpe]

Or a combine harvester that rebuilds into a dragster? 

[soapy]

I imagine there must be some sort of rechargeable battery that output the same voltage/current as 10 D cells in a smaller package which is also rechargeable...

..which is the missing piece of information: they are configured to give an output of..?

[unclesomebody]

I don't know exactly because the project is still in a conceptual stage. However, 10 D cells in series is simply a sum of their voltages minus any voltage loss due to internal resistance (isn't it?). I think this depends on the current too, but since I don't know the exact spec of the end product I'm kind of guessing at the moment. I just thought there might be some specialist battery shops on the web that I could check out for inspiration...

Yes dobbin, it's a propeller, which attaches to a rocket pack, which attaches to my back. I'm going back to the moon.

[SA Chris]

They may be configured as 5 in series in parallel with another 5 in series, or 10 in series. Unlikely, but possible. It depends on the voltage of the kit.

[Obi-Wan is lost...]

Next time your in Sheffield, nip into

The clues in the name. They know a LOT about batteries and are pretty likely to have something that will do whatever job it is you need it to do. Also pretty helpful when I've been in there.

[Jim]

Come one, Spill the beans Uncle. What you building?