Battery Question

[Texas_Rig]

I am having issues with my cranking battery. I've tested the battery 3x and it tests fine. It shows it's good but only shows 890cca but it's a 1000cca battery. Could this be the problem? I'm getting 4 hours of fishing before it starts to shows signs of being dead. I don't think my motor is charging my battery. It's my understanding that if I start my motor and give it some gas that my battery should go up in amps on a tester. Is this true? My battery reads about 12.7 amps cold and when I start the battery and give it gas then it drops to about 11 amps for a second and then returns to 12.7 but never gets higher. Any thoughts on what my problem/s is?

[huntertn]

12.7 volts (I think you meant volts) before you start and 11 volts when you give it some throttle sounds like it is not charging. It should come up above 12.7 to charge the battery a little after you started the engine even if you are not running anything else.

What engine do you have?

[Adrian]

If you're still talking about the Mercury EFI 175, then I would suspect it's your rectifier. Let me ask, had you or anyone in the past put the battery posts on backwards? I did this once on my EFI and it blew the rectifier immediately. The new rectifier I ordered had in line fuses to prevent that. With a working rectifier, the Battery should reach between 13.4-14.4V when running.

[Adrian]

BTW, the Rectifier/Regulator is in the back of the engine in the middle with several colored wires coming out of it. Look for burnt wire connectors. I documented the installation of mine. If the picture attachment works, I'll post what to look for.

[Texas_Rig]

Originally Posted by huntertn

12.7 volts (I think you meant volts) before you start and 11 volts when you give it some throttle sounds like it is not charging. It should come up above 12.7 to charge the battery a little after you started the engine even if you are not running anything else.

What engine do you have?

96 mercury 175 efi

[Texas_Rig]

Originally Posted by Adrian

If you're still talking about the Mercury EFI 175, then I would suspect it's your rectifier. Let me ask, had you or anyone in the past put the battery posts on backwards? I did this once on my EFI and it blew the rectifier immediately. The new rectifier I ordered had in line fuses to prevent that. With a working rectifier, the Battery should reach between 13.4-14.4V when running.

I suspect that could very well be the issue. I installed a new battery charger a couple weeks ago and I did accidentally hook the cranking battery backwards for just a second. Thx for the reply. Ive already changed the voltage regulator on the side. I will look to see if that's the problem.

[Adrian]

If you did in fact hook those posts backwards, that's definitely the problem. Hopefully your part you replaced had fuses. It only takes one spit second for that thing to fry!