Onboard Charger
 

Will my battery life be shortened (overcharging) if I leave the boat plugged in while stored at home? I have an 01 353 with stock charging system. Also, do 353's come with a 30 or 50 amp charging system (previous owner said it was 50 amp)?

Charger is 50 amp.I'm not sure of the official answer but I have many customers that leave the charger on 24/7/365 and have never had any problems,but always wondered myself.

I think the onboard chargers are automatic, meaning they shut off once full charge is achieved.

Should be fine - I have always left my charger on while I am gone, with fridge and other stuff on!

Thanks everyone, that's exactly what I wanted to hear. Didn't make sense Formula would put anything but a "smart" charger in their boats.

I happen to be looking at mine today for the same reason. My batteries have gone dead several times over the winter and don't appear to be holding a charge any longer. I didn't see anything on the charger to suggest it was a "smart charger" or not.

Dis-connected the Mercthode since it's drawing power 24/7 and will be installing new batteries next week.

Just opened up my 353 for the season. I left the factory installed 50amp charger on all winter long. Both engines cranked right over....this is my second winter doing this. NO problems either time........I always "plug in" when at home. Enjoy the season!!!! Eric

if the charger is a "3 stage electronic" charger, then your batteries will be fine. If the charger is a regulated float charger, then over time, you will need to keep a close eye on the water level, as it will boil out.

my 1991 311 came with a VERY nice all stainless steel REGULATED FLOAT charger by ProMariner. It would boil out about a half pint a month from each battery. It died in 96 or 97 and I replaced it with an electronic "Flyback" 3 stage charger, also from ProMariner. Never had any more boiling or warm batteries.

Proper charge curve for a lead acid battery is to
1) charge to a level ABOVE float voltage,
2) stop charging and allow battery to drop to float voltage,
3) maintain at float voltage with trickle current.

Since a regulated nonelectronic charger has no brain, it has to choose a float voltage that is below optimal charge voltage but above optimal float voltage. You never get the charge density that you're supposed to get, and you never get the proper maintenance level that preserves the battery chemistry,

To give you an idea of how important this all is, I use my Sea Ray as an example.

It has 5 batteries. The original 50 amp nonelectronic charger would boil out a combined gallon of electrolyte every 30 days.

A Newmar electronic charger with battery temperature sensors has been on the boat since 2000. That's 8 years ago, and I've not added ANY electrolyte to any of the 4 main batteries and only a splash to the generator battery.

I'm a true believer. That $700 Newmar has saved me the cost of 20 batteries, since the boat had needed replacement batteries every 2 years previously.

mc