Basically, yes, it will work. However, it will take longer to charge the batteries.
Two 12v automotive type batteries linked together in parallel (positive to positve, negative to negative) will be the same voltage as a single battery. Charge them using a 12v battery charger linked across the negative terminal of one battery and the positive terminal of the other battery. Connect the charger, switch it on and monitor at regular intervals.
Two 12v automotive type batteries linked together in series (positive to negative) produce 24 volts.
The charger voltage must match the battery voltage, so you cannot charge a 24-volt battery with a 12-volt charger. If this is how you are using yur batteries, then just buy a 24v battery charger. Connect it across the terminals at the ends of the two linked batteries and charge as you would for a single battery.
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1987 V20 w/1987 150HP Yamaha on a Shoreland'r Trailer
1978 16.5 Airslot w/1996 120HP Force on a Four Winns trailer
1996 V21 w/1993 200HP Mercury on a Shoreline Trailer
All towed by a 5.7L Hemi Durango.
If God didn't have a purpose for us we wouldn't be here, so
Live simply, Love generously, Care deeply, Speak kindly.
(Leave the rest to God)
Silence, in the face of evil, is itself evil. Not to speak is to speak, not to act is to act. God will not hold us guiltless.