New batteries, not starting

[specialk]

I have a dual battery Perko switch set up, starting this season, I noticed that engine would take a little longer and longer to start up each time we went out. I noticed the voltage showing 12.7-.9. But after the boat was running it would jump up to its normal 13.5. If I turned the boat off, and turned it back on it would start up just fine, it only had issues after sitting for the week. The batteries were a 2 y/o, and I did not take as good as care of them during the winter as I normally do. So, everything was pointing towards low batteries, I took them out and charged them a few times, they were always around 80% when I started charging them, but after putting them back in they would quickly loose there charge. I had to jump start them a few times and again after running they would do well. I went last week and bought new batteries, took them home, and charged them on the charger of the next week. Took them and put them in the boat, when I turned the Perko to all the voltage at the dash read 12.5, switched to 1, 12.5 and switched to 2, still the same 12.5. When to turn the boat over, it make a clicking noise like it was trying to but simply could not.

These again are new batteries, just minute off of the charger, they are marine batteries with more than enough amps.

There seem to be something that is not letting the power from the batteries be completely transferred to the boat. I have no idea. Very frustrating, took it to the shop, no one could find the voltmeter to verify, but as of 3 hours prior I was showing 13.5 at home on these new batteries.

Any help would be appreciated.

2008 Tige 22ve,

[specialk]

Also, when I try to crank it over it shows my voltage going form 12.5 to 11.2-.4, on 1,2 and All.

[chpthril]

Sounds like a starting going bad or a cable is bad. To start with, showing 12.5 at the gauge, which is 20ft away from the battery, is normal. Seeing 13.5 right after coming off a charger is normal, its called a surface charge. This reading needs to be ignored. That surface charge needs to be knocked off before an actual indication of a battery's state of charge can be had. A new wet-cell should be 12.8-13.0 static, as the battery. Again, seeing 12.5 on an analog gauge all the way up at the helm is normal.

The best way to tell if a battery is charged, is to check the volts, at the battery, with a meter. I do not trust gauges on charges that show a percentage, I want to see voltage. Same at the helm. If i am diagnosing an issue, I want to see actual voltage, not a helm gauge.

I would start with some voltage drop test on all the main battery cables. Those feeding the switch, the starter and the helm BUSS's. Both B+ and B-. next would be to check the amp draw of the starter. This can be down with the starter in place if you can find someone with the right equipement, but you may have to pull the starter and take to be tested.

[talltigeguy]

My money is on the starter or starter cables.

Your old batteries were probably not quite ready to be replaced.

[SBM1234]

X2.

Friend of mine had a similar problem, he replaced both batteries a few times before replacing the cables. Once he did, the problem disappeared.

[specialk]

Cables look ok, but pulled the starter off and it was rusted bad, I had two incidents where I had a fair amount of water back there, one was a freeze plug that came out and the other was a ballast hose that came disconnected.

Ordered the starter, and have a set of cables available as well.

Thank yall for your great responses like always.

[sotexwake]

Possibly a starter relay? Had this same problem on a friends boat before...