Leaderboard

The units themselves are at fault here, just like the gumstick itself. I have the same problem: both my R55, the R91 and both R900 won´t work with a fully charged battery. Have a look at the contact in those devices not able to run on a gumstick; it´s just a tiny tip of metal which wears down over time. It behaves like a spring and looses its elasticity over time, preventing firm contact. To avoid this I bought self adhesive copper foil, something like this: http://www.ebay.de/itm/2m-selbstklebende-kupferfolie-80mm-breit-/181351987183?pt=LH_DefaultDomain_77&hash=item2a396bb7ef I subsequently fashioned a tiny piece of thick copper out of this foil which fits into the battery door of those units. The copper will re-establish connectivity. The second problem is the battery itself: any NiMh battery does have some sort of Memory Effect (not like on NiCd batteries), to avoid it you´d need a charger that has a 'Refresh' function. I´ve bought this one three years ago: http://www.amazon.de/Technoline-BC-700-Akku-Ladeger%C3%A4t-schwarz/dp/B000WILI42/ref=sr_1_8?ie=UTF8&qid=1394886466&sr=8-8&keywords=eneloop+ladeger%C3%A4t It´s wonderful: not only does it charge other NiMh batteries to their optimal power, with two wires, a dummy piece of rubber and a claw it´ll refresh the prismatic gumstick batteries as well.