Carver Owners Forum

Hello -

I have a 2000 Carver 450 with twin 6CTA.

Have digital volt meters install on all batteries. The system is simple and appears to be stock with the exception that the previous owner did upgrade to a Magnum Invertor. The other components like the isolators, fuses and battery switches appear to be the original. House and Engine Starters are old school 8D's

Under shore power:

Original Charles Charger charges 2 starter batteries and 1 Genset starter
House is charged by Invertor

While underway, I don't seem to be keeping up on the House Bank via the alternator. I am seeing 12.6 volts while the two starters without any load seem to run around d 13.0 volts. Not much of load (did not measure) other than the invertor running a pair of fridges and modern electronics with a few lights left on. I have not started any trouble shooting or yet with amp clamps and was wondering if an electrical diagram is available (I wish Pat was available). It is my understanding from Tony at SBMAR that you want to see 12.9 volts to be holding steady on a house battery.

Everything seems to work great while running the genset. I would prefer not to do that and have a house bank that stays healthy without running the genset. Seems that a pair of 8.3 L beasts should keep my house bank happy.

I am wondering whether:

(1) Anyone have the main dc alternator to battery drawings for a 450?
(2) Is it typical carver to wire the two alternators to a single isolator?
(2) Is the second isolator typically used for the Charles Bulk charger?
(3) Has anyone upgrade the 22SI stock alternators - It might be possible that I run too much at lower RPM and that is causing the voltage loss on the house.

Any other comments or observations would be appreciated?

I doubt it's an RPM issue, unless all the cruising you do is at idle or just above.

Not sure if it applies to yours, but I thought some of these installations used one engine alt for start battery charging and the other for house battery charging. And in those scenarios there was also a fuse for the house battery charging on the bulkhead forward of the engine.

Without much of a load on an 8D, you'd probably see 12.6 for quite a while even if it's not receiving any charge, so I'd suspect you're not seeing any charge getting there from an alternator.

What do your isolators look like? (now many wires and how many outputs on each)?

I have a 99, 45 voyager withe same problem. The boat is a power hog. I swapped every halogen bulb with LED’s but the real power draw is the inverter. The inverter powers the fridge, ice maker and outlet for the salon stereo. The refrigerator (not original) runs straight DC. I don’t worry about the ice maker underway and don’t use the stereo either. I have disabled the inverter. The boat still drains the house battery on the hook and I often use the genset. I purchased another 8D that I will hook up to the existing house battery. I also did some reading on the battery isolators, apparently the type carver used draws a lot of amps. . I thought about doing something like this.

Thank you for posting this information and the diagram. I am away from my boat but had concluded that I do need to take a look at the isolator as well to evaluate the degree of voltage loss I am experiencing.

I found the following test procedure for isolator testing:

Check to see if the isolator is working with a digital multi-meter set on “DIODE CHECK” mode. Put the red lead on the alternator input terminal and the black lead on one of the battery output terminals…..you should get a reading around .4 on most meters. Then reverse the leads and you should get a reading of infinity. Perform this procedure from all of your alternator input terminals to all of your battery output terminals. If you get a different reading with the red lead on a battery terminal then the isolator is defective.

There are several more modern isolators available that I am considering installing:

https://www.promariner.com/-/media/inri ... 1027184114

https://www.sterling-power-usa.com/zero ... lator.aspx

Finally SBMAR does sell upgraded alternators with higher output at lower RPM

https://www.sbmar.com/community/topic/c ... r-upgrade/

Hello -

I spent some time working on the DC system in my Carver 450 with Cummins 6CTA engines.

Upgrades made:

(1) Replaced the original isolators with Victron ArgoFet isolators - including wiring in the excite circuit to ignition purple
(2) The previous owner at some point had disconnected the remote sensing wires which resulted in 0 output on the alternator!
(3) I replaced one of the 22SI alternators with a 24SI from SBMAR. I plan on swapping the other as well.
(4) After following the BWA Delco trouble shooting I had confirmed one alternator was bad.

Now I am happy to report that I have a solid 14.1 volts at idle. I was getting about .5 volts lost through the older diode isolators. The old 22SI require both remote sense connected and positive at B+ on the alternator at startup (to excite). The Argofet provides that functionality. Finally, on my boat the gen set battery is not wired to the isolators so only gets charged when the generator is running or on shore power.

The engine at idle with the new 24SI seemed to be able to provide plenty of DC to run the invertor.

Steve

The Victron isolators are nice pieces, I like the specs, the only ones I found to work with the situation I needed a good isolator for....