On Wednesday, October 2, 2013 12:46:32 PM UTC-5, John Marshall wrote:
I need advice about the best choice of batteries for an asg 29e. lithium

ion would be outside manufacturer's remit and the insurer's plus too many

risks-the fuel tank is directly above the battery housings. I would like

something with at least 9 amp hours, whether gel cell or mh.

Used NiMh in my LS8 for about 5 years and can add some advice on those. Found the life span not much different from Pb gel-cells at about 2-3 years in spite of using specific chargers. Advantage is weight, around half of the lead cells. Disadvantage in self-discharge rates, these are high and you have to top off the battery if you want full capacity. Voltage drop is steep, just like for a Pb-cell. Flying with LiFe-PO4 now and have had no problems.
Herb