I'd like to get rechargeable batteries for my DX true 30. Which ones would you recommend? I was thinking Li ions would be best but what current and voltage would be optimal?
Lithium ions, at a voltage of either 3.0v or 3.7v, combined to 6.0v or 7.4v, will KILL the pump diode and probably the driver almost instantly.. This is assuming that your laser is the pen-style running on two AAA batts. A single AAA Li-ion(10440) will die/overdischarge very quickly because of the high current draw from the driver, so running a battery plus a "dummy batt" isn't a good idea either.
Best thing to use is either e2 1.5v Lithiums, or some rechargeaBLE 1.2v NIMH batts. These are available all over the place, and from experience I can say some of the cheapo brand rechargeable ones that claim 1000mAh do a nice job