Battery or Stator or Regulator or my Mind?

[msn26753]

I just boat an older fish and ski boat with a 150 black Maxx 1990.. The cranking battery died on me so I took it to have it checked. It was a ac dekco cm24mf I believe thats cirrect modell number. The guy sold me a magna power marine battery 24m4.. I took boat out and after a few starts the battery died out.. so I switched to my backup ac delco battery. It cranked fine. I noticed on my depth finder that I was only running 11.8v while running wot. Whenever I trmmed I noticed it droped down to 9.5v. And went back to 11.8. It restarted fine for rest of the day. Sometimes if I was tilting motor and running slow it would be 11.3v but as soon as I throttled up it would go back to 11.8 but no highrr. In other words. Im wondering what is going on, my new battery just died out. I noticed its got less cca then the acdelco but im worriedbmy boat isnt charging battery.. I heard you suppose to have 13-14v while wot.. how dobi check and what dobi check. What about my new magna power battery? Is it still good?
Thanks

[msn26753]

Also I noticed that lights and gauges dim and flutter whenever I titlt or trim..

[bobkyle2]

First thing i would do would, be check all the battery cable connections. Even on the engine side. My trim zaps alot of juice out of mine also. But as soon as i let off the button its instant jump back up.

I'm pretty sure you should be over 14 volts at WOT.

[msn26753]

Yea.. I left acdelco battery charge for 3 hours ladt night and it only got up to 11.8vokts so im thinking it maybe bad battery. But it just puZzles me on the brandnew battery.. why did it die out. Im hoping its just not big enough battery versus my stator or regulator.

[EuropeanAM]

Better inspect your VOLTAGE REGULATORS (on or under the coil plate).

Look for any burnt spots, browned/blackened/burnt connectors, etc.

If ANY of these are noted, you will need to REPLACE both voltage regulators, and any damaged bullet connectors with OEM COMPONENTS.

Sherm @ Sherm's Marine (or we) would be more than happy to assist with your parts needs.... EMAIL or PHONE are the BEST means of contacting the Parts Department(s).

[bobkyle2]

I agree with Euro, Check those regulators.And you can even see some of the stator without removing anyhting.