Battery types in *ist battery grip (BG20)?

There are now a number of different AA size batteries, but the BG20 booklet says, "Use 4 1.5 AA size alkaline batteries only".

Other batteries can give better performance, Lithium technology AA cells, Titanium technology, and of couse NiMH and NiCd rechargeables. All give slightly different voltages, and I am concerned that some may damage the camera.

4 Alkaline cells give 6.0 to 6.5 Volts, depending on manufacturer.
4 Titanium Alkalines give about 6.3 Volts
4 Lithium cells give 7.16 Volts
4 NiMH rechargeables give 5.23 Volts
4 NiCd recharegeables give 5.1 Volts

This will obviously depend on the state of exhaustion of the batteries, but these Voltages were all measured for new, or fully charged cells.

I'm sure the battery grip Fg for the MZ6 says specifically "Do not use rechargeables", they also have a very low Voltage, and very low internal resistance, either of which could be a problem for a camera. I'm also quite concerned about the high voltage of the Lithium cells. I'm pretty sure the Titanium cells would be OK.

Has anybody got a more informed opinion on this? If possible I would like to be able to use the Lithium cells, as they supposedly give about 4-5 times better life than straight Alkaline cells.

Hello,

I'm using rechargeable NiMH 2100 mAh batteries in my MZ-3 and two MZ-5n and it works without any problems. Being in northern Sweden, I have also tested this power source down to -20°C without being let down.

Rataskanken

Thanks for the information on the rechargeables. I'll definitely try them on my MZ6, and if that's happy, I'll probably try them on the *ist. I'm fairly happy that they'll come to no harm on the rechargeables as they give a lower starting voltage than the Alkalines. I'm not going to try the Lithium technology batteries, unless somebody can assure me that they've used them, as their starting voltage is a bit highe than the alkalines.
Incidentally, the latest issue of "Which Camera" magazine had a good comparative test of AA batteries, where these Lithium cells came out as very good value for money, with a very good life. However, they did mention that not all digital cameras were compatible.
Pentax were very non-comittal in their reply to me on this subject, just a bland statement that only the alkalines should be used. I wonder if they've ever checked them out.

Cheers

Taliety