Carver Owners Forum

I have a Carver 406. Took boat out for the first time this season. After about an hour (under power at all times) I noticed the cabin lights getting dim and other DC loads like nav equipment were getting reduced DC power. I have a total of 5 batteries on the boat, one for generator, 2 starting batteries and 2 house batteries. I started the generator which in turn provided AC power to my Master Volt battery charger and the problem went away. Would condition of house batteries cause this issue or should the engine alternators maintain sufficient voltage to keep lights and other DC equipment running?

Alternators should charge and maintain ur batteries. Were ur batteries disconnected during storage and not hooked back up properly? Or are ur alternators bad? Did the volt meters on the dash register anything while engines were running? If ur battery banks are isolated by the battery selector switch and u were running on 1 or 2 and not all, you would only be charging one bank of batteries. Multiple issues would cause ur problem.

Just to add to what Mike said....check all your battery terminals for corrosion and tightness, bad ground connections can cause as well..your master volt will feed the 12v side regardless of the batteries, as you found out......good luck man.

You may have more than one problem; bad batteries, bad alternator/s, the way you're managing distribution with the selector switch. Your alternators should put out more than enough to maintain a charge depending on your loads at the time and providing you're at a decent rpm. You won't get full output from them at idle or slight higher for example. The best thing to do is take a meter reading right at your batteries with only one engine running then shut it off and do it again with the other engine running. Set throttle to about 1500-2000 rpm. You should get over 14V if your batteries are low.

Disconnect the batteries and do a proper battery test. If you don't have the equipment, have the marina test them or take them in to an automotive place and get them professionally tested. Do that after they've been on charge overnight.

Thanks to all for the information. I was just "puttering around" at about 800 RPM's. The gauges on the bridge showed around 14 volts on both. Also, I have an isolator feeding the house bank. Will try all suggestions. So what I am understanding is that bad house batteries may be the culprit even though I was under engine power at a very low RPM?

Heh there....My guess would be ,if you were seeing 14 at the bridge gages, then your alts are putting out....I would check my wiring and connections ( corrosion) and see what is what before making any moves....also that isolator. Remember like it says in your manual, do not turn the battery switch to off while the engines are running.....it should be a make before break type so switching between 1-2 and both is fine just don't pass thru the off position.

Could be a bad isolator, but if the batteries were disconnected for the off season, then I'd suspect they just didn't reconnect that line.