russ010
Well-known member
I've been running 2 29 series deep cycle batteries in parallel for about 4 months now... I have been having some problems with on of the batteries which is 6 months old - it seemed to not be holding charge well and giving out way too early. I checked voltages on it with the fluke and that particular battery read 11.2 and the other battery read 12.8, 2 days after being fully charged. I have been keeping them hooked up in parallel while not in use, and for charging... I contacted a rep at Optima and talked to him about the problems (these aren't optima batteries, I just wanted to talk to someone different)..
anyways, this is what he told me "Paralleled batteries tend to fight each other when they are at rest -- this causes premature discharge and a shortened life span. It's OK to parallel batteries temporarily with the battery switch, while charging, starting and running the trolling motor -- just avoid leaving the switch on 'BOTH' when no power is being drawn.
This is probably where my fault had been - I never thought about each battery robbing each other of power. When I had the same batteries hooked up in parallel, the voltage on the fluke was 12.6... unhooked, well the numbers are above.
I have to take one of the batt's back tonight and replace it because my charger on the battery that is reading 11.2 was flashing "Bad Bat"... I tried to desulfate it with the charger (some option that is built into the charger), and it stated that it can take up to 10 hours.. so this morning is when I got the reading of it being bad.
So in the long run.... unhook your batteries from parallel when you're not fishing.
to give some background... I fish every weekend and charge immediately when I get home. I unplug them the next morning and then it sits until the friday night I'm to go back out fishing. I hook them back up and unplug them right after I get the boat hooked up to the truck and get ready to leave. I guess from now on they will sit unhooked during the week.
anyways, this is what he told me "Paralleled batteries tend to fight each other when they are at rest -- this causes premature discharge and a shortened life span. It's OK to parallel batteries temporarily with the battery switch, while charging, starting and running the trolling motor -- just avoid leaving the switch on 'BOTH' when no power is being drawn.
This is probably where my fault had been - I never thought about each battery robbing each other of power. When I had the same batteries hooked up in parallel, the voltage on the fluke was 12.6... unhooked, well the numbers are above.
I have to take one of the batt's back tonight and replace it because my charger on the battery that is reading 11.2 was flashing "Bad Bat"... I tried to desulfate it with the charger (some option that is built into the charger), and it stated that it can take up to 10 hours.. so this morning is when I got the reading of it being bad.
So in the long run.... unhook your batteries from parallel when you're not fishing.
to give some background... I fish every weekend and charge immediately when I get home. I unplug them the next morning and then it sits until the friday night I'm to go back out fishing. I hook them back up and unplug them right after I get the boat hooked up to the truck and get ready to leave. I guess from now on they will sit unhooked during the week.