[HELP Technic Rechargable Battery Box

[glugglug]

My son has the lego passenger train set (60051), for which I got the rechargable battery box (http://shop.lego.com/en-US/LEGO-Power-Functions-Rechargeable-Battery-Box-8878).

The difference from the regular AAA train battery box is night and day -- it lasts longer and it's much less of a hassle to keep it charged so it's always ready to use. Particularly since you can charge it while it's in the train or even while it's running, just have to remove the roof to get to the charging port.

I'm thinking there should be an equivalent substitute for the technic battery box (8881) but I don't see one anywhere. I'm thinking the train battery box should work with technic models, but the capacity of 1150mAh @7.4V is under half what you get from 6 high capacity AAs. Then again it is less than half the size so maybe you could work 2 of them into the models and use them in parallel? The dimensions aren't such that you can just put two together in the space the larger technic battery box occupies though.

The fit of the batteries in the 8881 is kind of crazily tight, and I'd rather not be swapping the batteries in there frequently. Is there no rechargable equivalent?

[sdotcarter]

Yes its very usable with technic.

The only alternative is the rechargeable battery box of the same size for about $80 USD

[Blakbird]

There is only one rechargeable battery box but it works equally well with trains or Technic. However, it is a different shape than the 6AA box.

[dr_spock]

A LEGO brick separator (orange version) can be used to help take AA batteries out of the AA battery box. A small flat head screw driver works too.

[Gnac]

[...] you can charge it while it's in the train or even while it's running [...]

This is a bad idea, don't do this

[zux]

This is a bad idea, don't do this

Can you please tell more about it? I've seen this couple of times on photos from events. So wonder what kind of negative impact such usage could do?

[Riley-NZL]

I'd hate to image the price of an Rechargable 6xAA battery box from LEGO......

[Gnac]

Can you please tell more about it? I've seen this couple of times on photos from events. So wonder what kind of negative impact such usage could do?

Unless you have an extrememly long charger cable and have no obstacles around your track layout for it to snag on, I can see something getting yanked out as the train whizzes around. It's far too expensive a part to risk wrecking the charging socket and never being able to top it up again.