The original hourmeter on my Scag Tiger Cub started to read 9999.9 and would show the actual time when I pushed on one corner of the LCD screen. I chatted with the parts man at my local Scag dealer and he told me that Scag knew of the problem and had changed vendors. I bought a new meter but I don't remember if there was any display before I installed it. Scag meters do have an internal battery and a memory that indicates maintenance due regarding engine oil change intervals. The display stays live and when I store this machine for the winter. I remove the battery and put it in one of my GTs that only gets used in winter.
I cut the old hourmeter open on my bandsaw and was able to pry out the memory battery and it was a standard button battery that is used in some watches and computers, however potted in epoxy in the hourmeter.
The hourmeter in my Ingersoll 4018 GT is an analog type and will click away when the keyswitch is on regardless if the engine is running or not and will eventually kill the battery.
Today I was at my local Scag dealer looking over the Scag machines in their show room and I noticed that both Tiger Cats on display showed a clear screen on the hourmeters. The batteries were not installed in these machines, so I'm not sure what initiates the display in these meters.
I was just doing a google search for hourmeters and there is every configuration possible available. It all depends what the OEM specifies from the vendor.