Logo
FULL SITE MENU

Occasional overcharging on e90mlcos

J

john_day

Member
This is a 1985 90hp evinrude. I had some problems in summer with overcharging. I replaced the rectifier and then the battery. The battery is a duralast 24md dl, 685 mca and 140rc, deep cycle.

if I have a fully charged battery the motor will chargeup to 17v, however, if I discharged the battery by turning on running lights and ff about a half an hour before I leave and keep both on the entire time Im out the motor charges around 12.5-13.7

is this due to the battery being deep cycle?

Thanks
John
 
is the battery a sealed maintenance free one?..you probably have a rectifier only charging system....you will need a older battery type where you have to add water...

you will be ok with a load such as your running lights...if you run the motor with just the battery and no load you will eventually lose the rectifier..another option is to replace the rectifier with a regulator assy...i would just get the right battery for the motor and use this battery for the trolling motor etc..
 
Yes you, should not use deep cycles as starting batteries. Now if it's a deep cycle/staring battery that is maintenance free your charging system won't like it. This is because your motor uses an unregulated charging system which voltage will fluctuate by quite a bit. This means you will need to check the water in the battery frequently. If your battery is rated for starting but is deep cycle maintenance free you have 2 choices replace the battery with a standard starting battery or replace your regulator with a combo unit from CDI regulator/rectifier.
 
Thanks for the replies.

The battery is not maintenance free, just deep cyclr, lead acid

Does using a deep cycle battery for starting hurt anything?

Running the boat with appliances does work fine, I will buy just a starting battery. I read the battery should only have about350cca. Does that sound right?
 
that's what the book says but its going to be hard if not impossible to find a quality battery that size...just get a quality non maintenance free battery and you will be ok...
 
Back
Top