Low voltage

[26aftcab454]

Maybe the batteries are starting to wear down. they came with the boat almost 3 years ago. 1996 7.4 Mercruiser kept in slip year round. always kept on trickle charger . 2 batteries on perko switch.
When engine running-no accessories on 12.6Volts
Engine running with blower, bilge. nav lights,stern lights,interior lights on 11.8 volts
With blower running engine off ( ready to start) 11.8volts

So far no problem starting but do not want to get caught on the water not being able to start.

Do you think I should replace the batteries?

I appreciate your input-Joe

 

[DianneB]

Re: Low voltage

I hope your meter is wrong!

With the engine running (about 1,200 RPM) you should be seeing the charging voltage of your alternator, about 13.5 to 14.5 volts depending on temperature. If the alternator is working, you should not see any change in voltage (to speak of) between accessories on and accessories off. A lead-acid battery wont begin to charge until about 13.2 volts.

You don't seem to be seeing that under any condition so #1 - meter is wrong, or #2 - alternator needs repair.

It sounds like the battery is doing the best it can under the circumstances.

 

[26aftcab454]

Re: Low voltage

I was kinda thinking the altenator may be the issue- the chagrer keeps them up bewteen outings.