Battery question ???

Classic Parker Boat Forum

Help Support Classic Parker Boat Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.


Active member
Mar 3, 2006
Reaction score
Up until now my 2003 Parker has performed flawlessly. All maintenace done as required etc.... The last few trips the port battery has started showing signs of age. Batteries are original to the boat (460 hrs). Motors are twin F200's. Alternators are to spec per the tuneup this past spring. Batteries are group 27, I have a group 31 almost new. Can I put this in place of the port battery? Starboard battery is strong still. Or ? Should I replace it with another new G27?
If you ever run your switches in the "both" position, I'd replace them in pairs with the same battery on port and starboard. Lots of discussion over on TheHullTruth about battery charging, combiner circuits, isolators, battery switches, etc. Concensus seems to be to not run the switches in the "both" position except in emergency, and let each alternator charge its own battery.

If you want to install a group 31 battery, you may have to swap out the battery trays. Here is a link to one of the first projects (with pics) I posted to ClassicParker.
Thanks Pc, will do a search on THT and look for additional info. I have a spare batt tray that will fit the G31 batt and should be able to cut and mount as you did. I never run both so I guess I should be okay in that dept, always one on 1 and one on 2 and reverse the next time out.
thanks again