les v,

Just an idea - the Hobart charger you are talking about is equipped with what is commonly called "an egg timer" charger. This means 1.) it is very, very old; 2.) but the user is guessing how long the battery needs to be charged - the 8-10 hr hour charge cycle is a close "guessitmate" of how long a battery that has ~20% charge remaining to be recharged. If you set the timer to 8 hours of charge time but the battery is only 30% discharged you will "cook" the battery , shorten the life, have electrolyte spill out the vent cap, etc. 3.) Today's chargers are referred to as auto "start/stop" or "Smart" chargers - they will start charging when you want them to & stop the charging cycle when the battery is fully charged - eliminates the guess work on your part.

Contact a or more than "a" local battery/charger distributor(s) & see if they have a "good" & tested charger that could work for you & sized to your charger. There not too expensive but not cheap. They might even take your "Hobart" in on trade.

Not trying to spend your money but it is good advise for the long term.

Finally does the battery have a lot of "white" powdery stuff around the top of the battery & white drip lines down the sides of the steel battery case. If so this is a sulfate that has been formed from loss of "electrolyte" (aka battery acid over time. This could be an issue you might want a battery guy look at. DO NOT ATTEMPT TO ADD ACID ON YOUR OWN - YOU WILL NEVER GET IT RIGHT INS SPITE OF WHAT OTHERS MAY TELL YOU OTHERWISE.