You just broadened my knowledge a little more . Thank you, Davere: I put a voltmeter on the batteries and the both were in the 14.5 range.
1st, have you ever tested your DVM against a known, accurate DVM or measured a 'known,stable voltage ? It's possible your DVM isn't reading the real voltage. A reading of 14.5 means 'somewhere between 14.4 to 14.6'. ALL DVMs, all digital meters, are ALWAYS +-1 last digit..nature of the beasts.
2nd, did you test AFTER putting an 1157 lamp on the battery for 5 minutes ? If not, you'll always read 'high', as there's a 'surface charge'. You need to put a 'load' on the battery to drain away these extra electrons'. Depending on the battery you'll need a certain load for acertain amount of time.
3rd, what type of battery ? There's at least 5 different ones on the market, each requires a specific method of charging(volts vs amps vs time ), good 'maintainers' will have 3 'stages' to charge the battery, better ones will have 4 or 5, including a 'desulpurator' stage( the 1st one..). They also will do a 'load test' to ensure battery is up to snuff. My 'old school, SCR based' charger has 3 'types', manual, regular battery, maintenance free, basic desulp and auto shutoff.