Hi Simon,
The pack and charger that I'm testing out at the minute are borrowed from my model planes and are not suitable for long term use in this application.
These packs use lithium tecchnologies and there are several different types: li-ion, li-po and li-fe, plus a few others.
the Lithium pack for domestic use must have an automatic low voltage cutoff (LVC) built in. You must also use a special lipo/li-ion charger, as incorrect charging can cause fires. I've seen plenty of these and its no joke.
In fact it is not recommended to charge or even store LiPo batteries indoors and never charge unattended. I do charge my packs indoors sometimes, but only with the pack in a special fire-proof container.
Li-ion packs are probably ok for domestic use, but still need the special charger and low voltage cutoff device.
If my testing is successful, I'll buy one of the packs that others are using, that has the lithium charger and LVC built in. I will however double check that the cells inside are li ion and not lipo. Interestingly, there are many identical looking packs on eBay that are listed as li ion, not lipo.
Cheers,

