3200SCR Battery & Electrical Questions

[ertyqway]

It's been a great summer for boating here in the Pacific Northwest, and the weather mavens are predicting we'll have a relatively warm, dry autumn and winter as well. I intend to stay on the water as much as possible right through until Spring.

I've got a lot of time on my new-old Maxum now, and a better feel for what needs fixing, adding, etc. I'd been thinking the electrical system would be needing an upgrade this winter, but the issue has been forced by the failure of one of my four batteries last weekend. Thus, I want to throw out a few questions to the Maxim Brain Trust and think out loud a bit.

First: what exactly do the battery switches under the cockpit sink control? There are two rotary switches, with labels noting positions 1, 2, and Both. I've tried via trial and error to figure out how those labels correlate to the actual battery connections (starter, house, left, right), but it's defeated me. It doesn't make any sense. Assuming it's actually wired up correctly (I know...) what is each switch position SUPPOSED to do?

Second, I'm seriously considering switching the house bank over to 6v golf cart batteries for better performance. We spend a lot of time at anchor, and I think that's what finally killed one of the old deep-cycle 12v units. I've had several people recommend 6v golf cart batteries for better house bank longevity. Anybody made this switch? Thoughts?

Third, if I do swap the batteries, does it make sense to relocate them for better balance? I've got the classic SCR port side list due to the batteries and galley throwing things off kilter a bit when the holding tank is empty. Adding two more batteries is only going to make that worse. If I relocate, where?

Fourth, I think I need AC power: a generator and/or inverter. Lack of AC power at anchor is becoming problematic. No way am I buying 5kW Kohler or anything like that. Aside from space issues (I LIKE being able to get inside the engine compartment to work on stuff), it's just too expensive to add to a 20-year-old boat. That leaves either a 3000W inverter with a house bank big enough to drive it, or a Honda eu2000i portable on the swim step. Any thoughts pro or con?

[cdhunter]

Perhaps the attached picture may answer your question about the battery switches. This is from an owners manual for a 3100 SCR.

[shrew]

6v are heavy. I have 2 group 31's dedicated to the house bank and I have a Honda 2k that I run for approx. 3 hrs a day. That keeps me going for up to 10 days on the hook, and still being able to play the stereo 6-8 hours per day and run the fridge non-stop as well. it also helps by doing little things, like replacing all the bulbs with LEDs. This drops your power consumption from 1 aH to .01 aH.

[HavaMax]

Originally Posted by cdhunter

Perhaps the attached picture may answer your question about the battery switches. This is from an owners manual for a 3100 SCR.
Attachment 3648

Does anybody have something like this for the actual 3200 series?? Preferably the early years.....94-98.....please and thank you!!! I have never really figured out the way it should be set. I have always just set my battery switches to both and monitored my usage when away from the dock.

[CGG]

Got me thinking too! Anyone know how I should set batteries on a 2000 3300SCR. When running I have always put both on 1.

[HavaMax]

Maxum must have published some kind of guideline.....??? Anybody??

[Phillbo]

Originally Posted by HavaMax

I have never really figured out the way it should be set. I have always just set my battery switches to both and monitored my usage when away from the dock.

That is very risky. You could potentially drain both batteries. Only use one at a time.


Here is my set up.

Batt #1 - Starting Batt
Batt #2 - Deep Cycle House Batt

I start in position #1 and leave it there while out running around (pos 1 charges both batts / pos 2 only charges batt #2). Then when I get on the hook and turn off the engine I switch over to Batt #2. That way you only risk draining your house batt and always have a good starting Batt.

[ezcurra]

Interesting reading. In my 3200SCR, the two battery switches control the starting batteries for the port and starboard engines. There is no house battery, so I am not sure how that comes into play. The BOTH setting ties the two batteries together so can deal with having one one weak battery (or I assume one bad alternator), you can still get both engines up and running.

I like your thoughts on running an AC through a battery bank and a good inverter (mainly since my Westerbeke decided to throw a rod and I can't fix it - and not sure I want to - until I pull a powerplant). They both seem to have some a long way and it might be more doable than it was a few years ago. Still investigating.

Take a look at the 3200 owners manual (http://www.maxumownersclub.com/forum...3200%20SCR.pdf) - from 1996. It shows each battery handling its engine and and its set of DC circuits.

Hope this helps, and not just confuses things even more!

Gerard

[jamanati]

I have a 95 3200 scr with same setup (two batteries on port side). I had an old/broken/rusted 5kw gen on the stbd side that I removed and threw out. Haven't replaced it yet.
The best way to understand this is think of the boat with two circuits (1 and 2). I think port is circuit 1 and starboard is circuit 2, or vice versa)
-) Each circuit has an energy source - a battery.
-) Lets say the switches weren't there at all, then there are 2 mutually exclusive circuits where each one is fed by its own battery.
-) The two fuse blocks under your helm, one is directly connected to circuit 1, the other is connected to circuit 2.
-) Then there are a variety of items directly connected to the batteries (bilge pumps, CO2 sensor, windlass main breaker, etc), those aren't tied into any switches.

The switches are there to help cross over the circuits. Meaning, devices on circuit 1 can be fed by the circuit 2 battery, and vice versa. For instance if the port battery was dead, your port engine wouldn't start, and the devices connected to the port fuse block wouldn't work.

If both switches are set to "1", then both engines and more importantly both fuse blocks are feeding off the circuit 1 battery. The circuit 2 battery is just sitting there. Some people do this as to allow the circuit 2 battery to be used for the house when needed. So they drive around on the circuit 1 batter, and when they anchor out, they switch both switches to the circuit 2 battery as to have both fuse pannels feed off the circuit 2 battery (most don't know which fuse panel is used to power the fridge, radio, lights, etc, so they switch both switches). Now the fridge/radio/etc feed off the circuit 2 battery. This prevents drain on the circuit 1 battery.

If the circuit 2 battery goes dead while anchoring, you can switch both back to the circuit 1 battery and be able to start the engines. Driving around with both switches set to "1", the engine's alternators will *not* charge the "2" battery. Those with 120vac battery chargers have them hardwired to the batteries and will charge both when connected back to shore power. But driving with switches on "1" will not charge the "2" battery. While engine running, you could switch the switches back to "2" in which case those batteries will start charging again via the alternator.

Other people like to have one switch set to "1" and the other set to "2". This makes everything work as if there were no switches at all, meaning, one engine and one fuse block pull from one battery, the other engine and the other fuse block pulls from the other battery. This is done mostly by folks who don't anchor. It extends the life of both batteries since they are used mostly equally.

The "both" setting simply means that circuit draws from both batteries. This is normally used if both batteries are weak and neither battery is strong enough to crank an engine. So using "both" can provide just enough power to get an engine started. "Both" can be used when anchoring out to extend the usage of fridge/radio, but only use it if you have a generator with its own battery that is connected to a battery charging system. This way the generator starts, charges both engine batteries enough to crank both engines. The generator is turned off, and each running engine now charges its own battery. Kind of cumbersome if you ask me, but only helps in a gen/3rd power set up.

As for the generator I pulled, given its 300lb+ weight, my boat listed quite a bit to port (generator was on starboard, with 2 batteries and waste tank on port).

I bought 4 inexpensive battery trays and got 4 old dead batteries from my mechanic. Installed them on the starboard side, boat is more level now. The batteries act as ballasts and are easily removable when doing work in the bilge. Sure, I could move the 2 batteries from port to starboard, but that would be mean more work on my part, plus the costs. Carrying around 4 dead batteries does add some weight, but I figured in the overall weight of the boat and that it had a generator from the start, I just deal with it. Sorry for the long winded explanation, but hope this helps.

[ezcurra]

Great write up. I learned something today. I assumed the position 1 and 2 on each battery switch was more like - this bank, the other bank. I.e., Putting both at position 1 meant each bank/ starter fed / drew from "it's" battery. I spend most of my time in marinas, not on the hook, so I guess it has never been an issue since the battery charger is usually on.

When you pulled your gennie, did you pull an engine or did you dis-assemble it in place to pull it out? I am thinking this might be a good winter project when things cool off here in FL, but I still have to get the engine itself up and over the starboard motor.

Thank you!

Originally Posted by jamanati

I have a 95 3200 scr with same setup (two batteries on port side). I had an old/broken/rusted 5kw gen on the stbd side that I removed and threw out. Haven't replaced it yet.
The best way to understand this is think of the boat with two circuits (1 and 2). I think port is circuit 1 and starboard is circuit 2, or vice versa)
-) Each circuit has an energy source - a battery.
-) Lets say the switches weren't there at all, then there are 2 mutually exclusive circuits where each one is fed by its own battery.
-) The two fuse blocks under your helm, one is directly connected to circuit 1, the other is connected to circuit 2.
-) Then there are a variety of items directly connected to the batteries (bilge pumps, CO2 sensor, windlass main breaker, etc), those aren't tied into any switches.

The switches are there to help cross over the circuits. Meaning, devices on circuit 1 can be fed by the circuit 2 battery, and vice versa. For instance if the port battery was dead, your port engine wouldn't start, and the devices connected to the port fuse block wouldn't work.

If both switches are set to "1", then both engines and more importantly both fuse blocks are feeding off the circuit 1 battery. The circuit 2 battery is just sitting there. Some people do this as to allow the circuit 2 battery to be used for the house when needed. So they drive around on the circuit 1 batter, and when they anchor out, they switch both switches to the circuit 2 battery as to have both fuse pannels feed off the circuit 2 battery (most don't know which fuse panel is used to power the fridge, radio, lights, etc, so they switch both switches). Now the fridge/radio/etc feed off the circuit 2 battery. This prevents drain on the circuit 1 battery.

If the circuit 2 battery goes dead while anchoring, you can switch both back to the circuit 1 battery and be able to start the engines. Driving around with both switches set to "1", the engine's alternators will *not* charge the "2" battery. Those with 120vac battery chargers have them hardwired to the batteries and will charge both when connected back to shore power. But driving with switches on "1" will not charge the "2" battery. While engine running, you could switch the switches back to "2" in which case those batteries will start charging again via the alternator.

Other people like to have one switch set to "1" and the other set to "2". This makes everything work as if there were no switches at all, meaning, one engine and one fuse block pull from one battery, the other engine and the other fuse block pulls from the other battery. This is done mostly by folks who don't anchor. It extends the life of both batteries since they are used mostly equally.

The "both" setting simply means that circuit draws from both batteries. This is normally used if both batteries are weak and neither battery is strong enough to crank an engine. So using "both" can provide just enough power to get an engine started. "Both" can be used when anchoring out to extend the usage of fridge/radio, but only use it if you have a generator with its own battery that is connected to a battery charging system. This way the generator starts, charges both engine batteries enough to crank both engines. The generator is turned off, and each running engine now charges its own battery. Kind of cumbersome if you ask me, but only helps in a gen/3rd power set up.

As for the generator I pulled, given its 300lb+ weight, my boat listed quite a bit to port (generator was on starboard, with 2 batteries and waste tank on port).

I bought 4 inexpensive battery trays and got 4 old dead batteries from my mechanic. Installed them on the starboard side, boat is more level now. The batteries act as ballasts and are easily removable when doing work in the bilge. Sure, I could move the 2 batteries from port to starboard, but that would be mean more work on my part, plus the costs. Carrying around 4 dead batteries does add some weight, but I figured in the overall weight of the boat and that it had a generator from the start, I just deal with it. Sorry for the long winded explanation, but hope this helps.

[Phillbo]

Why would you get rid of an asset like a gen set just to replace it with dead useless weight?

[ezcurra]

When the genset throws a connecting rod, it becomes a dead useless weight until you spend $1,000+ to pull it (you have to pull the starboard motor), and another few grand to rebuild it (or $5k to replace it). No doubt it is a valuable asset, but you have to ask yourself how many assets (dollars) is it worth to replace that asset. Basically, I have a boat prewired / plumbed for a generator with a dead weight where it belongs!

[ertyqway]

So, we've got a couple of different (and conflicting) explanations for the battery switches. That's making me wonder now if I need to rewire those as well in order to have the system operation make sense.

I'm settling on getting a Honda eu2000i for a swim step genny. Anybody else got one? Thoughts? I have read about the reverse polarity grounding issue, but it sounds like there's an easy fix for that.

The battery choice is still open. If ezcurra's description is correct, I may not actually have separate house and starter banks as I had thought. Some digging around this morning in the engine bay seems to confirm that: four wet batteries, all with the same product number, and all about 15 years old. That's not good.

So, a whole new set of batteries is in order, and that gives me a chance to improve the system. Switching from wet to gel is high on the list, but that means a new charger too. A new charger opens the door to an inverter/charger as a possibility (uh-oh...MISSION CREEP). a genny plus inverter seems like a belt-and-suspenders approach, but inverters are great when rafted up (no noise or fumes). Then the Genny becomes the charger for the inverter system instead of direct house power, and can be run at times and places where it's more sensible to do so. But a functional inverter probably means an 8D house battery (or two), which needs a place to live that won't further un-balance the boat.

And now I'm looking at a $3,000-plus solution to one battery dying. The admiral will not be pleased .

[jamanati]

When I pulled my old/dead/rusted/broken generator, I disassembled one piece at a time. I kept all the original wiring/harness and tucked it behind the water heater. It did take me a few hours to take it apart piece by piece. It came down to the last two major parts, the 4-cyl engine, and the coil itself. The engine wasn't that heavy, its apparently an aluminum block. The coil on the other hand was pretty heavy, but still manageable. Bring a friend if you need an extra hand. But it can be removed without pulling the starboard motor out, you just have to take it apart. The frame itself that the generator was bolted on was rusted and shot. I took off the exhaust hose and capped it off with a rubber cap from Home Depot with 2 clamps. The fuel line, plugged it and clamped it as well.

As for whether or not to replace with a generator or an inverter, that's a different discussion. If hot water or a/c is needed, then a generator is the way to go, but, if all one is looking for is some tv, fridge, and radio, then an inverter isn't a bad idea. I'm not a fan of a portable generator as you also need a portable gas container, and with 3 little kids on my boat, I just prefer not to.

[ezcurra]

Thanks for the first hand experience jamanati. I might just tackle it after all!

[jamanati]

You're welcome. After I pulled the generator out, on a calm day, I place a 4 ft level across the back of the boat and added the dead batteries until it leveled out. 4 batteries is what it took. With the generator out, I also had easier access to replace the broken blower motor hoses. I may one day move the waste tank from the port side to the starboard side, but I think it will list again when the tank is empty. So for now, the 4 dead batteries could possibly be replaced by 4 good batteries and an inverter in the future. Uh-oh, there's an idea!

[ertyqway]

As a final, anticlimactic resolution to my original post: the cold snap we had a few weeks ago finally killed off my battery bank for good. Needing to be up and running for some near-term events, I replaced them with similar (but higher quality) wet cell 12v units rather than trying to change chemistry or type. Having fresh batteries has made a huge performance improvement.

Still no genny yet, but will likely get a Honda EU2000i for the swim step after the holidays.

[mmwjr]

Enjoy glad you are still getting time on the boat, post some pictures to share your fun and make us jealous

[AlwaysSober]

Originally Posted by ertyqway

As a final, anticlimactic resolution to my original post: the cold snap we had a few weeks ago finally killed off my battery bank for good. Needing to be up and running for some near-term events, I replaced them with similar (but higher quality) wet cell 12v units rather than trying to change chemistry or type. Having fresh batteries has made a huge performance improvement.

Still no genny yet, but will likely get a Honda EU2000i for the swim step after the holidays.

Our '96 3200 SCR has two 80 pound group 31 AGM batteries + another that is only connected to the battery charger (currently a spare battery to someday power a small inverter).

The battery switches are set to "1" and "2" so that the alternators aren't fighting one another. Set both to "Both" if one battery goes dead.

Be careful with that generator on the swim platform. Make sure it has enough output for your AC unit. Make sure it's secure in case the boat gets rocked. Make sure a CO detector is functioning so everyone wakes up the next morning.

[Soaring Eagles]

Great to see data about a 3200 SCR, that's the type I have also. And mine is a 1995