Have any of you checked the prices and availability of batteries for our aircraft? Virtually every battery that will work is OUT OF STOCK everywhere. The only battery I could find that was in-stock anywhere was the "old-fashioned style" Gill G-242 with the screw-on black cell caps. ALL of the newer sealed Gills and Concords where unavailable, with varying estimates of when they would be in stock. (FYI - The Concords with "M" designation don't require the battery box as they have a place built-in where the strap-down metal bar goes. A good option if your battery box is shot, or a way to recoup some funds by selling your good box that you would no longer need.)
I checked for a lithium-ion option, but, as is common with the Skymaster, there is not one available for our airframe. PLEASE correct me if I'm wrong!
Regarding prices, every sealed battery was $800 or more! This seems like highway robbery to me, when equivalent non-PMA batteries are maybe 25% of these prices.
My Gill RG24-16 sealed battery was nearly dead after sitting for awhile. It showed 10 volts on my multi-meter. I removed it from the aircraft and broke the seal on the cells to check acid levels. The seals warned "WARRANTY VOID IF REMOVED" but who cares as the battery is long out of warranty! Every cell was below the level of the lead, so I topped off with distilled water. (FYI, the cell caps require a 5/8" socket to unscrew.)
I tried to charge it with a 12/24v "smart" charger, but due to low voltage, the charger was not "smart" enough to realize it was a 24v battery and not a 12v. I connected it to a 24v forklift battery and let it sit overnight, knowing the voltage would equalize between the batteries. This morning the battery showed 24.6v, and I put it on the smart charger which now sees it as a 24v battery. Its currently charging at 26.6 volts at 8 amps, but that will go down until it reachs the float stage when fully charged.
So I think (pray) I dodged a bullet this time, but if you find yourself with a bad battery, you could be stuck for weeks unless you want an old-fashioned non-sealed battery.
And if you have a sealed battery that's out of warranty, it may be a good idea to check the electrolyte levels and top-off as required.