Some wiring and device questions

[drh1965]

I spent the weekend crawling around my "new" old boat trying to figure out how everything is plumbed and wired. I came across some very screwed up wiring and some problems. While I'm a complete newbie to large sailing vessels, I am an EE so I felt at least partially armed to make progress on the electrical systems

Some background... I was told that there were 4 Gel 73 aH batteries configured in 2 banks 3/1 and they were a few years old. I found that there was an attempt to wire them that way but it was done incorrectly. That batteries were all bought October of 2002. 3 of the 4 (the house batteries) were completely dead. One read 5V. One 0V. And one had the positive post completed blown/corroded off (not sure which). All 3 of these batteries where swollen and ugly. The cranking battery was marginal to ok.

The condition of these batteries worried me (ofcourse). So, I started doing the wiring diagram and cringing alot.

At least I found what appear to be good/operational devices. There is a 100A Balmar alternator with a remote ARS3 adjustable, multistage regulator. It works fine. This made me happy. This also explained why the amp meter was not working. It is only rated for 70A and was disconnected when the Balmar was installed. There is a Perko 1/2/both/off switch that checked out fine. There is a Guest 10A, 3 stage, shore power battery charger that appears to be working. Last, I found a Sure Power battery isolator installed. After digging around on net, I think I determined that it is a device that allows alternator output to split to two output posts with a diode on each branch. When voltage is seen on its Regulator connected post, it allows current to flow downstram through both diodes and then on to the batteries connected to these posts. It also "should" only allow current to flow upstream from whichever battery bank is being driven (but not from one bank to the other). Can anyone corroborate my findings? Anyway, I'm not sure whether ot not to keep this device installed. I suspect I could correct for the voltage drop across the diodes by increasing the bulk, adsorption, and float voltages at the ARS3 but this isolator device makes me a little uneasy. Anyone have any comments about these "isolators"?

Thanks for reading this.

[Lynx]

I think that the batteries are shot.

On the other electronics. When do you plan to start full time cruising?
If not in the next 2 years, try to get by on what you have. The same way with most other equipment. Start on other projects.

[GordMay]

For your reading enjoyment & edification ...

Some worthwhile reference articles from Blue Sea Systems:
Resources - Blue Sea Systems

Including:

Battery Isolators and Automatic Charging Relays:
Battery Isolators and Automatic Charging Relays - Resources - Blue Sea Systems

And:
Preventing Cycling in Battery Combiners, Voltage Sensitive Relays, and Automatic Charging Relays:
Preventing Cycling in Battery Combiners, Voltage Sensitive Relays, and Automatic Charging Relays - Resources - Blue Sea Systems

and many more Application Briefs, References, and Technical Briefs ...

[rleslie]

drh1965

When we purchased our 20 year old boat, I spent a full week trying to figure out the wiring and all the problems associated with it, including under-sized wires, poor connections, batteries not charging, hot wires running to nothing, etc, etc.

After a week of total frustration, I pulled out every wire in the boat and started fresh, with all of our charging devices run through a battery combiner. I love the combiner.

Since you are a EE, you will probably be able to re-wire the entire boat long before you correct all the screw-ups that predeeded you.

Just a thought.

Roger

[drh1965]

Originally Posted by rleslie

drh1965

When we purchased our 20 year old boat, I spent a full week trying to figure out the wiring and all the problems associated with it, including under-sized wires, poor connections, batteries not charging, hot wires running to nothing, etc, etc.

After a week of total frustration, I pulled out every wire in the boat and started fresh, with all of our charging devices run through a battery combiner. I love the combiner.

Since you are a EE, you will probably be able to re-wire the entire boat long before you correct all the screw-ups that predeeded you.

Just a thought.

Roger

I'm with you. The pulling out has already commenced. I'm just trying not to pour too much money in right off the bat. Those batteries are $240 a pop! I figure I'll make use of whatever still works and possibly simplify things a bit. For instance, I'm not overly concerned with having to actually use the 1/2/both/off switch to charge whatever bank needs charging. If my kids decide to throw the switch to off while the engine is running... well, they'd make good chum

[drh1965]

Originally Posted by Lynx

I think that the batteries are shot.

On the other electronics. When do you plan to start full time cruising?
If not in the next 2 years, try to get by on what you have. The same way with most other equipment. Start on other projects.

Yep. I've already written off the 3. I'll probably use 3 new ones for the house banks and the old one for the starter bank.

I'm also just trying to get things functional and will probably just make do without whatever is broken or marginally useful.

[drh1965]

Originally Posted by GordMay

For your reading enjoyment & edification ...

Some worthwhile reference articles from Blue Sea Systems:
Resources - Blue Sea Systems

Including:

Battery Isolators and Automatic Charging Relays:
Battery Isolators and Automatic Charging Relays - Resources - Blue Sea Systems

And:
Preventing Cycling in Battery Combiners, Voltage Sensitive Relays, and Automatic Charging Relays:
Preventing Cycling in Battery Combiners, Voltage Sensitive Relays, and Automatic Charging Relays - Resources - Blue Sea Systems

and many more Application Briefs, References, and Technical Briefs ...

Very helpful links. Thanks!

[rleslie]

Originally Posted by drh1965

I'm not overly concerned with having to actually use the 1/2/both/off switch to charge whatever bank needs charging. If my kids decide to throw the switch to off while the engine is running... well, they'd make good chum

If you don't want to fool with battery switches, you should definitely go with a three bank battery combiner. You can run your charging sources to any battery bank (whichever bank is the shortest run) and let the combiner determine how to distribute the charge. Then, if you need to combine the batteries for any reason (starter batt dies and you need to pull from the house) there is a manual switch that combines them.

I did install three ON/OFF switches, one at each bank; but that is so I can disconnect each bank individually if needed. They have rarely been used, but convenient.

Roger