9693 Rechargeable battery pack question...

[dougwalton]

Hi everyone - I need some clarification. I'm in the U.S., and I'd like to upgrade my Mindstorms 2.0 to use a rechargeable battery setup.

1. Is there a better/cheaper place to buy it than the Lego website (at $55.95)?
2. Do I actually also need to buy their #8887 power transformer ($24.95)? It's unbelievable that they charge so much for something like that.
3. Once installed in various robots, does the rechargeable pack require robot construction changes to accommodate its possible larger size, or does the rechargeable pack take up the same amount of space on the brick as when using regular AA batteries?

Overall, I'm astonished that a rechargeable battery setup is looking like it will cost me just shy of $100 when it's all said and done. I guess that's just too bad, eh? Are there other alternatives?

Thanks for your help!

[iplewis]

Are there other alternatives?

AA NiMHs?

[dougwalton]

My assumption was that I would want a rechargeable battery pack so that I wouldn't have to disassemble a robot in order to get to the batteries for replacement or recharging. Is this an incorrect assumption? Thanks...

[mattallen37]

You could look on eBay and Bricklink for used packs, and also for the transformers.

The dark bluish gray battery pack requires the AC transformer.

The white battery pack requires the DC transformer.

The white battery pack has a higher capacity, so you don't have to charge it as often (I think it's about 2000 mah vs. 1400 mah).

You can charge them while in the NXT, so just build your robot so that you physically have access to the charging port.

The battery pack sticks down by 1L compared to the AA battery cover, so keep that in mind when building.

[jwiger]

MinuteBot is working on an alternative to the battery pack. It is purely outlet powered, but will be cheaper overall then the rechargable battery and it's power transformer.

http://www.kickstarter.com/projects/378 ... r-robotics

They are looking for initial funding now. They just have a prototype but if they get enough money raised they will go into production.

[dougwalton]

I'll give some thought to the MinuteBot thing - thanks.

Ended up buying rechargeable pack and transformer (9693/8887) from the Lego store. Ridiculously overpriced ($56/$25), and yet, they were the cheapest source I could find. Oh well...

[ggrinton]

Hey, you should try buying one in Australia! The markup on the US price is about 60% for the identical product.