Hi all,
I've successfully modified my ES-1 to have an internal rechargeable battery pack. I've written up an illustrated DIY guide, for anyone interested in trying it with their Electribe mk 1 or 2. It's in the Yahoo Electribe group, in the FILES section (you have to join as a member, though to access the FILES section). I'd post it here also, but its too big for the attachment file size limits on this site.
http://launch.groups.yahoo.com/group/electribe/ There is also a video clip of it in action there as well.
Although it's written for the ES-1, it may also be relevant for the other Electribes (not X-tribes, though), so long as there is the space in the casing for it.
This has worked out really well. Depending on which batteries you choose, you could get up to 10 hours continuous use out of a charge. I chose cheap, small AAA 900mAH rechargeables that were locally available, and I get over three and a half hours out of them continuously. Other batteries that I suggest in the guide will give a lot longer.
You can also use the modded Electribe itself as a portable battery pack to power other 9V DC equipment, simply by switching a switch and plugging in a DC extension cable into the charging socket to a guitar pedal, drum machine, or even another Electribe!
It also uses the standard Electribe DC 9V power pack as the charger, so there's no need to buy a separate charger. It will charge a battery pack the same as mine in about 10 hours. You can also use the Electribe WHILE CHARGING the batteries.
The mod also features reverse polarity protection for the battery pack, in case another, incorrect polarity power pack is plugged into the charging socket.
Here is a teaser pic below.
Cheers, graham