Strange battery Issue

[airdvr1227]

2 battery setup with a Perko switch. Battery 1 is also direct wired to the bilge pump. I don't have a meter so I'm throwing out the symptoms to see if anyone has any ideas. Both batteries replaced this spring. Both batteries connected to trickle chargers at the dock. When I'm running on battery 1 the motor runs badly, missing and stumbling. When I switch to battery 2 it runs fine. Charging gauge on dash is the same with both batteries. I thought possibly battery 1 was bad but it starts the boat just fine. I'll take a meter with me this weekend. What should I look for? Do alternators get weak?

 

[bruceb58]

Re: Strange battery Issue

Very odd. Measure the voltage with a meter at the battery and at the coil while running. Ground your meter to the block when measuring the voltage at the coil.

Check the ground connection on battery #1 and where it connects to the block as well.

 

[airdvr1227]

Re: Strange battery Issue

Yes. Only p;roblem with that scenario is the batteries share a common ground. Also going to be checking the connections at the switch.

 

[bruceb58]

Re: Strange battery Issue

Yes. Only p;roblem with that scenario is the batteries share a common ground. Also going to be checking the connections at the switch.

Does the ground cable from the block hit battery #1 or #2 first? I personally run separate cables from each battery to its own connection on the block.

 

[glenn property of pam]

Re: Strange battery Issue

2 battery setup with a Perko switch. Battery 1 is also direct wired to the bilge pump. I don't have a meter so I'm throwing out the symptoms to see if anyone has any ideas. Both batteries replaced this spring. Both batteries connected to trickle chargers at the dock. When I'm running on battery 1 the motor runs badly, missing and stumbling. When I switch to battery 2 it runs fine. Charging gauge on dash is the same with both batteries. I thought possibly battery 1 was bad but it starts the boat just fine. I'll take a meter with me this weekend. What should I look for? Do alternators get weak?

battery one could have dropped a cell. You wouldn't notice it on starting unless the boat was a real pain to start and you had to crank for long periods. You either need to pull the batteries and have them tested or buy a cheap meter to test them. Most dropped cells are due to low water causing the plates to warp and trickle charging over long periods can cause a battery to require re-filling. another possibility is the perko switch causing a problem so if you have the batteries tested and they test good then put battery one in battery 2 position and see if the problem follows the battery. Bruce makes a good point on the ground cable being the problem if battery one is connected to battery 2 before it goes to the motor.

 

[Grub54891]

Re: Strange battery Issue

Battery switches can get coroded also. Snap the switch quickly through each setting a few times-not running- that cleans the contacts a bit. See if it changes.
Grub

 

[fixnfly]

Re: Strange battery Issue

What motor is on your boat? Is it EFI?

 

[airdvr1227]

Re: Strange battery Issue

Thanks for the responses. Turns out it's the switch. I can live with 1 battery for the rest of the season.