Upgrading House Bank

[MarkA]

My existing house "bank" is a single 12-volt, which I'm guessing was around 85 ah when new. Now, it's about 5 ah.

I'm considering 4 Trojan T-105 6 volt batteries. Wired in series parallel, they'll give me 450 ah at 12 volts. $512.00 and 248 lbs. total.

I'm also considering 3 Trojan SCS225 Group 31 12-volt batteries. Wired in parallel, they'll give me 390 ah at 12 volts. $675.00 and 198 lbs.

Any thoughts or recommendations?

I have a 50-watt solar panel and charger that works very well here in So. Cal. I don't know what kind of alternator I have (can't read the label without removing it), and I never use my shore-power charger.

 

[u079721]

This type of question usually gets as much response as "which anchor is best?"

I used a pair of group 31 Trojans as my house bank, with very good results. Of the two options you suggest you couldn't really go wrong with either. I think most folks would probably recommend the 6V batteries - cheaper, more capacity. I would have gone with them myself excpet that I could't easily find a storage spot that was tall enough. If you can fit them in, I don't see why you wouldn't choose that option.

Just remember that if you start to seriously take advantage of all that capacity you may need to upgrade your system to be able to put the amp-hours back in without running your engine for many hours a day. The most efficient use of a battery bank is to cycle between about 80 or 85% down to 50% (depending on which "expert" you listen to). Your 450 amp hour system would therefore provide a useful 135 to 158 amp-hours. If you have the stock 50 amp alternator that is going to take a LONG time to charge the house bank.

 

[Tom Metzger]

A question:

Mark - If you got along for an extended period of time with one 85 ah battery why do you now want to increase by a factor of four or more? That's a rather dramatic increase.

How do you plan to charge this bank. Obviously, not with a 50 w solar panel and a fifty (?) amp alternator.

It looks to me as though you are going to end up spending a $1k or more.

I just want to make sure that you have thought out the whole project.

YMMV

 

[MarkA]

Tom, those are good questions.

I've been using little energy, but I intend to increase my carbon footprint soon. We're usually out for only 3-4 days, and the solar charger has been plenty. But there's no refer, no chart plotter, no radar, no inverter for the laptop, no electric dinghy inflator. All of that is changing soon, and I'd like to cruise for weeks at a time, instead of days.

I realize I'm putting the cart before the horse in the sense that I haven't yet calculated my energy needs. But my existing batteries are on their last breath now, and I figured I'll upgrade my capacity, (including whatever charging capacity and regulation and monitoring systems) now, and hope it will cover my increased needs when I acquire the electronics.

Bad move? Should I just replace what I have and figure out my needs as I install the rest?

 

[Loren Beach]

Time to consult the Archives?

Mark,
There are a number of *excellent* threads on this subject on the site.
Cllck on "Search" and then enter something like Trojan t-105 or Trojan t-145 and click on GO.
You will find many threads with copious information and pictures from many different Ericsons.

Best,
Loren

 

[Tom Metzger]

Mark - Of the things you mention, only the fridge uses a lot of power, unless you spend a lot of time on the laptop. Since both options you suggest involve paralleling schemes, you could install just one leg at this time and increase it when you need more power.

In the meantime you could install the other stuff you will need, alternator, regulator, charger and battery monitor. It would come down to how fast you want to dissipate your cash. And if the fridge isn't coming soon, you have to consider the life of the batteries you install now. It's true that unused batteries will last longer than heavily used batteries, but they still get the same physical pounding regardless.

BTW, you don't need an installed inverter to run a laptop. I use a Xantrex 140 watt unit that plugs into a 12 v outlet.

I would probably go with one twelve volt battery now, based on cost and need. I tend to be "thrifty".

**********

A little off topic, but one thing I find interesting is that in battery threads lots of people need and install large banks, and in engine threads these same people talk about how much they use their engines. It would seem that if running the engine a lot the batteries would stay charged or it wouldn't be a problem to run it to charge the batteries. I hope no one gets the impression that the only way to live is with 400 ah house banks. It ain't so. Diesel is cheap compared to installed amp-hours.

Again, YMMV.

 

[MarkA]

A little off topic, but one thing I find interesting is that in battery threads lots of people need and install large banks, and in engine threads these same people talk about how much they use their engines. It would seem that if running the engine a lot the batteries would stay charged or it wouldn't be a problem to run it to charge the batteries. I hope no one gets the impression that the only way to live is with 400 ah house banks. It ain't so. Diesel is cheap compared to installed amp-hours.

Again, YMMV.

Good point. I used only 23.6 gallons of diesel between Thanksgiving 2006 and Thanksgiving 2007, and we sailed and/or motored 55-mile round-trips at least 35 times, for 2-5-day stays on the hook. (Yeah, the kids love Catalina) The M30 Perkins gets pretty good mileage. On the other hand, we never ran it for charging -- only for motoring. The solar panel handled 85 percent of the charging.

Time to pour another martini and dive back into Calder's book.

 

[MarkA]

Oh, and did I mention that I've been hand-steering 100 percent of the time? A tiller pilot is coming soon. What do they draw?

 

[Tom Metzger]

A tiller pilot is coming soon. What do they draw?

That's a tough question. It depends mostly on your boat and where you take it. It uses very little in standby, 60 ma, but as much as a few amps when moving the rudder. From your experience you know how hard you work on the tiller. I would expect you would use two or three amp-hours/hour on a very hard day. Others may have a better estimate.

It's not something I pay attention to while day sailing. The fridge draws around that amount 24/7. I mostly recharge my batteries after four or so hours sailing while powering into the anchorage and anchoring. Judging by how many people go to Catalina there must be a fair amount of powering when you get there. Diesel is cheap, and an engine suffers more from disuse than use.

 

[rwthomas1]

I look at battery bank power also as a safety issue. I like to make sure there will be plenty of emergency reserve to keep nav gear, vhf, etc. running if things go very wrong. Currently I have 3 group 31's for the house bank and this is plenty since I don't use the refrigeration. Another caution is alternator upgrades. The alternator is easily upgraded. The problem is that upgraded sheaves may not be readily available for your engine to allow for the larger belt. I need to have custom sheaves built to take full advantage of my new alt/reg package. This is a more difficult problem than it would seem, trust me. Lastly I also carry a Honda 2000watt generator on longer trips and to recharge the batteries while at the mooring. Careful use can mitigate the CO risks and it is very cheap to run, quiet too. RT

 

[Tom Metzger]

Rob - I guess I was talking about you.

For how many weeks do you go out at a time? Without a fridge and with a little care you should be able to go for about two to three weeks on your house bank, and you still have your unused starting battery. That would be my idea of things going very, very wrong. Most of us don't do that.

My longest is eight days without an engine going to Bermuda. The two grp 27s made it without a problem, including some cranking.

It's true, new crankshaft pulleys are a problem, but you will not have a problem running a 1/2" belt on a Universal diesel 3/8" pulley. The belt only sits a little proud on the pulley, and the contact length on the crankshaft pulley is double that of the alternator. As long as you run a good quality belt you will get good belt life. Some people say the 1/2" belt will bottom out, but according to a Gates Belt engineer both groves have the same side angles, 38*.

 

[jmcpeak]

I have two 12v marine batteries as my house bank. I don't have a dedicated starting battery, I should, but don't.

My trusty "jump-pack" has saved me at least two times. I never leave the harbor without it. I consider it a safety item every boat should have.

Jason

 

[rwthomas1]

Tom,
Yep, my setup is overkill however there are a few things to remember:

I inherited the batteries I am using for a house bank, the 3 group 31's. Originally 2 were house and 1 for start. I added the 4th group 31 for starting and just tied the original 3 together. The cost increase to do this was pretty small.

I upgraded to a 100amp alt/reg package as the boat is on a mooring and never at a dock for shore power recharging. The original 3 batteries were chronically undercharged by the stock 50amp alt and single stage regulator.

Currently (no pun intended) the electrical demand is low but that was a concious decision. Running the AB refrigeration was hard on the batteries as the system works hard due to poor icebox insulation and lack of air to the condenser due to poor installation choices. All inherited problems.

The future will bring better insulation, inprovements to the AB systems location, etc. It will also include a belowdecks autopilot. Using these systems I expect the electrical demands to triple or quadruple. The upgrades I have made should easily handle them.

I have tried to get the engine pulleys to not eat belts but they ate a Gates belts last season. I finished the season on a 3/8ths belt. Being a belt-n-suspenders type I would like the correct pulley groove sizing for the crank and waterpump pulleys. I have two possible sources for locally made custom pulleys in aluminum. I have checked pulley alignment with straitedges and metal rods. They are correctly aligned.

Here is the situation where I might need the extra battery capacity: Enroute to or from either Cuttyhunk or Block Island the weather turns from reasonable to ugly. Unforcasted and unpredictable the weather in New England does this with regularity. Increased headwinds and larger seas slow progress enough to end up running against a tide which slows us down further. Then the fog rolls in. All this means running the radar full time, nav gear, vhf and if the schedule is far enough off, nav lights. Now I could always start the engine to keep up with demand however nothing is 100% reliable. If the engine fails or the alternator dies there will likely be enough juice to get us home. I've also been pinned down for days by weather that was predicted to be 15kts and proved to be 35kts. Having the extra juice while sitting in an anchorage is nice.

While my setup may be overkill, the cost so far is nothing compared to the money I have spent on sails, running rigging, accessories, etc. To each his own, I wouldn't recommend my methods unless they work for you. Everybodys situation is different and we all should be happy and comfortable with the changes and choices we make. Given that MarkA is going to be increasing electrical demands exponentially and going out for weeks at a time makes a system-wide upgrade seem smart. Granted he could wait until the parts are installed and the need is there before proceeding.....

RT

 

[MarkA]

Why is nothing easy?

I'm looking at upgrading the alternator to a 110A Balmar, which is the largest that can be driven by a 1/2 belt. Not only are the pulleys on my Perkins Perama M30 3/8" wide, but the mounting brackets on the alternators are not sufficiently offset to fit into my engine "room." I'd go even bigger, but I'm concerned about side loads on the water pump bearings and the crank seal.

If I can't find replacement pulleys, I guess I could have my existing ones machined out. Or, I could go with an 80A model and get a decent 3-stage charger for shore power?

I've decided to go with two Trojan T-145's for the house bank, for now. That's 260ah that I can cheaply double later if we become power hogs.

I'm thinking a Balmar Duo-charge for the starting battery, or maybe the Xantrex Echo Charger. Then I can get rid of my combiner. Do any of you have experience with these?

Advice for an AC charger? Battery monitor? Regulator? The Balmar regulators seem to offer more control options than the Link 2000R -- or am I missing something?

Thanks in advance.

-mark

 

[rwthomas1]

Mark,
If I had it to do again I would likely go with a 80amp alternator so the 3/8" belt would be completely adequate. Machining the existing pulleys will likely not leave enough meat on the side of the sheave for reliability.

I am less concerned about the side loading of the waterpump and crankshaft seals. In my case I have a Universal/Kubota which is an industrial engine that is very understressed in my application. Crankshaft side loading with even a 1/2" belt would be a non-issue. The waterpump runs on the "slack" side of the belt. That is when the alternator loads up the drive side of the belt stretches marginally and the slack side actually gets looser. The actual grip on the belt is from the wedge shape of the pulleys/belt and the slack side need only maintain enough tension to fully seat the belt under load. Sure, you can over tension the belt and stress the waterpump but correctly adjusted belt tension should not present a problem.

Regarding the choice of alternator/regulator. Much has been written and a search will produce plenty of info. I went with Ample Power and I am generally pretty happy with their product. They are not user friendly but the design of the electronics is supposedly superior. That said, it would be difficult to fault going with Balmar. They are the biggest, available most any chandlery, and the products are user friendly.

The Ample regulator has a solenoid control that trips in and out based on charging voltage. The starting battery is automatically charged by this setup so I don't have to worry about it. Its a simple way to deal with the starting battery.

I am looking into the possibility of converting the V-belt drive to a serpentine or flat belt setup. The flat belt would not be a true serpentine setup, just run like the V-belt. The advantage is greater surface area with less tension. This will require some time in the junkyard searching for appropriate pulleys but I am an old pro at that since I used to build hotrods in a former life..... The new Betamarine engines come with belt setups like this and the local Beta dealer also said I could order and try and pulley I wanted and return it, no charge, just shipping. I will certainly post this info if I can get it to work.

RT

 

[Tom Metzger]

More for the same 2 cents

Mark - I would want a separate engine regulator. You don't want to lose all means to charge the batteries for one failure.

I am not a fan of installed inverters so I won't comment on them, other than to say don't let the inverter run the boat if you lose shore power. It doesn't take long to dump a battery through a water heater. However, if you want all of the comforts of home you need an inverter

FWIW, Balmar chargers are made by Xantrex.

I am also not a fan of combiners. They are worse than an Echo Charger, but I wouldn't have either. They over charge the starting battery and lengthen the time to charge the house bank. Most people don't use their starting battery to start the engine anyway. Regardless, it only takes about a quarter amp-hour to start it. Rob's grp 31 battery will start his engine 520 times on a single charge. Seriously though, if you are on a dock with shore power I would only use shore power to charge the starting battery. When you are away from the dock give it a few minutes charge every several days. Before you do though, use it to start the engine as a reliability test.

For the same reason I would not put a battery monitor on the starting battery. If you don't use it, why monitor it?

 

[rwthomas1]

Tom,
You are correct in saying that a combiner will generally over charge a start battery and increase charging time. The paralleling solenoid in my setup can, and has been, modified with an inline switch. I can choose to not parallel if I wish. I generally leave it on for two reasons: The starting battery I use is an Interstate LHD series, IIRC, specifically designed to be very resistant to over charging. The second reason is I monitor the regulator and the charging times are not overly long before it trips to float so I don't worry about it right now. In future if the charging times warrant, it is a simple matter to switch off the start battery while charging. I admit that I do not have a battery monitor. I use the admittedly inaccurate voltmeter but since the bank is oversized for its current use this has not been a problem.

If I had it to do all over again then I would likely have taken Guy's advice and modify an 80amp Leece-Neville for external regulation and go with a simple 3 stage regulator like the Xantrex (looks like a rebranded Balmar).

No setup is ideal for all people and they all have their drawbacks. What I like about this site is the exchange of ideas allows people to decide what would be best for them.

RT

 

[u079721]

Combiners?

I too have wondered about the use of combiners and their tendency to overcharge the smaller battery bank (or starter battery). I installed a combiner when I first got my boat as a way to keep the starter battery charged while cruising. But after awhile I became concerned about overcharging, and decided to disconnect it. I would start the engine from the house bank, so I didn't really need to top off the starter battery at all while on a month long cruise, so I just left it alone. Since it was only there in case I should draw the house bank all the way down it ended up being just a 66 lb insurance policy - probably overkill, but it made me feel better.

I did have on-off switches for both the house bank and the starter battery that would allow charging of either or both with the alternator. Not fool proof, but it worked for me.

 

[Tom Metzger]

For reliability, test it.

Steve - If you are going out for a month you should periodically test the starting battery to insure it will work when you need it. You won't drain it, but you will know that it will work when you need it. Just reading the voltage is not really an adequate check.

 

[Rocinante33]

Mark,

For an alternator option, you might want to consider the Leece-Neville (Prestolite) 90 amp marine instead of the Balmar. It costs much less and is much easier to install, at least on a Universal. It is the same case size as the old Motorola 55 amp. Balmar is a larger case, so it often requires bracket modifications. I use a 3/8" belt without any slippage problems, knock on wood. It has an internal regulator which is all I use, but there is apparently a way to bypass it and use an external (such as a Balmar). See previous threads on this site as well as the excellent web site by Maine Sail on his installation in a Catalina. He reads our Ericson stuff and, since Loren named him an honorary Viking, maybe he will chime in.