Im not sure this was ever used.
John Deere Automatic Battery Charger & Engine Start/Timer 12V 50-amp TY27733 OEM
DieHard 200.71222 Fully Automatic Battery Charger Engine Starter 12V 2/10/50 Amp
Schumacher Electric Battery Charger Model SE 5212aFully Automatic 50 Amp Starter
Schumacher SE-5212-A 2/10/50 Amp Fully Automatic Starter Charger Made in USA!
Battery Tester Battery Tender 12V at 100 AMP/6V at 50 AMP
BATTERY TENDER 100 AMP @ 12V 50 AMP @ 6V BATTERY LOAD TESTER