Battery wiring

[Tom.B]

So the "starter" batteries are actually dual-purpose batteries. So should the house bank die, we still have some small version of a house bank as an option. That's why I'm not a fan of using straight starter batteries at all. I have two banks and they can both function as backups to each other.

 

[dhays]

May I dare to ask why you need to select what is the house bank? Usually starting batteries are not intended to be used as service batteries if I am right. I clearly understand the value of the switch to select what to use to start so in case of a flat starting battery you can either start only on house or combine both but I do not see the opposite way.

One reason is if your house bank completely dies for some reason. You would then have no Nav lights or radio. In his setup, he could then connect the start batteries to the DC panel and still have those functions.

 

[ghost]

Someone asked about my D.C. Genset that has the ability to be hand cranked. It's a single cylinder Kubota. It does have an electric fuel pump so if not enough fuel left in the lines, you might have to rig something to get it going. I tried it once, and on the second try, got it to fire. You spin it with the crank without compression, and then quick as you can, drop the compression lever and let the momentum fire it.

http://mvghost.com/Voyages/?m=201205

Honestly, this kit was more work than I planned, and for most folks I would actually not recommend it. I currently can not remote start it and have to run back, throw the throttle, turn the glow plug, then start with starter. Actually designed and have working an arduino micro controller that can automatically start and monitor, but it's on a breadboard and needs soldering and final install. I could actually auto start from my amp monitor with it, but for 4 years I just do it all manually!

 

[ranger58sb]

I really need some basic help, here is what I have on my 76 CHB 120 Lehman, 55amp alt, two 8d lead batteries as well as one group 27 start battery for the gen.

I would like to add a start battery just for the main engine. I want it separate so I don't have to worry about running the "house batteries" down.

I have a three bank Protech 1240 charger that is working great I see no reason to change it out

I have the same charger. One thing to watch for is bank imbalance. You'll see in the manual they suggest each of the three banks be approx the same size. Not suggesting it's a showstopper...

When I began our battery upgrade -- two large banks, one small genset battery -- the battery guy (not a charger guy) said my proposed set-up would probably be fine.

Over the years, though, I noticed the 1240 sometimes went to float on all three banks prematurely -- perhaps when sensing the genset small battery was fully charged? Or sometimes it instead seemed to be overcharging the small genset battery.

FWIW, I eventually installed an inverter/charger attached to one of the large banks, removed the genset battery from the 1240 altogether (genset has it's own alternator)... so the 1240 now only services the remaining large bank. The 1240 seems to be better, now.

In your case, a very simple/inexpensive alternative might be using the 1240 for only the house bank -- letting your genset and main alternators charge their own start batteries. (Maybe something like a G31 for main engine starter?) A simple pair of jumper cables can be a pretty effective back-up for main and genset starters.

Or another step up, especially if you don't already have an inverter and may want one, could be to put an inverter/charger on your house bank -- which maybe offers inverting advantages anyway -- and using the 1240 for your genset and main start batteries. Happy to help you spend your money.

Anyway, just thought useful to mention that imbalance thing for your consideration...

For your original question... another way to skin that cat might be to just connect your genset starter to your Lehman, too. If the single G27 won't start the main, maybe just add another G27 to that "bank." The main alternator could well keep that charged enough for your needs, and if your genset has an alternator, genset use would augment to that anyway. And like I said, a set of jumper cables is cheap back-up.

-Chris

 

[stone beach]

Ghost
Gen set / kit, make / model / supplier info please. Cant see any of that from your blog. Thanks

 

[dhays]

You guys have forgot more about this than I know.
I really need some basic help, here is what I have on my 76 CHB 120 Lehman, 55amp alt, two 8d lead batteries as well as one group 27 start battery for the gen.

I would like to add a start battery just for the main engine. I want it separate so I don't have to worry about running the "house batteries" down.

What is the simplest way to give me peace of mind, I hear it hard to push start a boat

I have a three bank Protech 1240 charger that is working great I see no reason to change it out

My thoughts similar to Ka_sea_ta with some small differences. I am going to assume that you have the typical 1/2/Both/Off switch. Many boats with a two battery battery bank will have one battery connected to post 1 and the other to post 2. For example, I have attached two photos of how my sailboat was wired from the factory and then how I changed it to add a start battery. I had both a 1/2/B/Off switch and an On/Off switch. In this situation the 1/2/Both/Off switch not only selects the battery that will be used, but it also selects which battery will be charged by the alternator. The only way both batteries are going to be charged with the engine is if the selector is in the Both Position.

The second image shows how I changed it to add the start battery. I have used the same two switches and just added an Echo Charger (you could use a Balmar Duo-Charger or a Blue Seas ACR depending on your battery types). The idea is that both the Alternator and your charger are charging your house bank of 2 x 8d wet cells. The Echo-charger in this case is then charging your start battery. Again, unless your engine is having problems (which you should fix) a single group 31 should easily start your main under all conditions and is only getting topped off by the Echo-Charger.

In normal operation the 1/2/B/Off switch is left in the 1 position and the On/Off switch is turn On when you go to start the engine and turned off after you have shut it down (although it could simply be left in the On position). If for some reason your start batter fails, you then turn the 1/2/B/Off to the Both position and the On/Off switch to the Off position. You can can now start the engine and run your DC panel with the House Bank. If the House bank has failed, you turn the On/Off switch On and the 1/2/B/Off switch to #2. This allows you to keep your critical house loads running with your start battery (VHF, Nav lights, etc) so you can find your way to some place to fix your House bank problems.

As another has mentioned, you could use the same start battery for your genset and main. OTOH if your genset has its own alternator, you can just let your genset charge its own battery and keep it entirely separate. If your start batteries are also wet cells, you can use an ACR or Echo-charger. If the start battery is an AGM, then I would use a Balmar Duo-charger since you can set it charging current appropriate for the AGM battery.

Just a thought...

 

[kev_rm]

Just a thought...

I am not a fan of a switch between starter and battery. You already have one. Its the solenoid which is far more capable and reliable than a rotating one made for loads significantly less than 1000+ amps.

 

[psneeld]

obviously haven't heard of the thousands of cases of latched solenoids and starter fires.

 

[Tom.B]

I am not a fan of a switch between starter and battery. You already have one. Its the solenoid which is far more capable and reliable than a rotating one made for loads significantly less than 1000+ amps.

You must not have yet experienced a runaway starter. It's a little scary.

 

[kev_rm]

obviously haven't heard of the thousands of cases of latched solenoids and starter fires.

Yep just also heard of the billions (literally) of installations without them.

 

[kev_rm]

You must not have yet experienced a runaway starter. It's a little scary.

A few. Didn't need a plastic switch to solve them. Hammer or pull cable.

 

[Tom.B]

A few. Didn't need a plastic switch to solve them. Hammer or pull cable.

Ok... so if rummaging through a tool box for a wrench or hammer when your starter is locked or in a running state is your thing, suit yourself. I thinks a 600A switch is a easier, better, and safer solution.

Blue Sea Systems HD-Series On-Off Battery Switch

 

[psneeld]

I have had probably half a dozen in my life from helos to boats to trucks.


Maybe I am unlucky...but in all reality, I cant think of someone who operates equipment a lot that hasn't at least had one.


It is a possible emergency that myself and many have had...and none of the others that people worry about so much.

 

[Island15]

Thanks for all the input.
My system currently has no switches.
Is there any reason that the new starting battery could not just have it own charger? I was just thinking of installing a small independent stand alone unit.

 

[Ka_sea_ta]

Thanks for all the input.
My system currently has no switches.
Is there any reason that the new starting battery could not just have it own charger? I was just thinking of installing a small independent stand alone unit.

The ACR will allow charging from the charger on your house bank.... or tie the + terminals of your house bank batts together and move one of the charger leads to the starting batt... either way make sure all your batts have the same chemistry....

 

[Tom.B]

A three bank 60A charger, when hooked up to three banks, only delivers 20A per bank. I have all three outputs of my charger tied together (to balance all the mosfet output circuits as a precaution) so I get a full 60A to my house bank off shore power (as needed). The starter tops off through the ACR. With the small amount of battery capacity it takes to start an engine (generally) there really isn't a reason to give a start bank it's own charger.

 

[dhays]

Thanks for all the input.

My system currently has no switches.

Is there any reason that the new starting battery could not just have it own charger? I was just thinking of installing a small independent stand alone unit.

We each will have an idea of how a system "should" be configured as well as admit that there a lot of good way a system could be configured. A suggestion I would make is to do what you are done NT now and get opinions. Do some reading from the "experts" and then decide how you would like to have your system configured.

Once you know what you want to do, then you can come up with a strategy to get there. In my case, I drew up a diagram of what I had, and then came up with some interim configurations that would get me there. You don't have to do everything all at once.

I would want switches to be able to disconnect my batteries from both my DC panel as well as the starter. Switches are relatively cheap.

The other I would suggest is that you ensure that you have all of the positive battery connections properly fused within 7" of the battery. Unless your boat was updated, this will likely not be the case.

If you have an overall plan, switches and fuses can be added to fit in with how you want your system to be ultimately configured.

The other thing to consider is what battery would you want to use for a start battery. If you want to use an AGM and keep your LA house bank, then you wouldn't want to use an ACR or Echo-charger. Instead you would select a Balmar Duo-charge for example.

Anyway, figure out what you want and then come up with a step by step strategy to get there.

 

[ghost]

Ghost
Gen set / kit, make / model / supplier info please. Cant see any of that from your blog. Thanks

Aquamarine mytygen

 

[ranger58sb]

Is there any reason that the new starting battery could not just have it own charger? I was just thinking of installing a small independent stand alone unit.

Not huge reason not to do it that way... aside from space, cost of extra unit, associated wiring and fusing, and installation. Just have to weigh those against other approaches.

It can be an efficient set-up, though, especially if it lets you get better service from your other charger on your other banks. Your 1240 gives you 40 amps, but spread that across three banks, means sometimes closer to 13 amps per bank.

FWIW, and if it's possible a decent Group 31 battery will start that Lehman (you'd have to check those specs)... and depending on your expected usage patterns for the boat... a relatively easy approach could be to install something like an Odyssey PC-2150 (Group 31) AGM battery for your engine... and call it good.

Maybe just be sure you engine alternator is appropriate; might be all the charger you need.

If starting from fully charged, the thing will sit for months without self-discharging appreciably. Run your engine occasionally -- as you would when simply using the boat -- to fully recharge. Sort of like a car battery set-up.

Separated like that, you wouldn't have to worry much about mixing charge voltages for FLAs and AGMs. Adding a separate charger would just be gravy. But a simple set off jumper cables could protect you from anchorage embarrassment

Wouldn't be difficult to add cabling and switches to accomplish that "parallel bank" thing in a more elegant (less-redneck?) approach (compared to jumper cables)... but that might not be worth your effort, unless you're just looking for a project to pass the time.

-Chris

 

[FlyWright]

You must not have yet experienced a runaway starter. It's a little scary.

Yep just also heard of the billions (literally) of installations without them.

A few. Didn't need a plastic switch to solve them. Hammer or pull cable.

IMHO, all boats should be able to deselect all electrical power with a series of switches easily located within reach OUTSIDE of the ER. The closer to the helm, the better. Anything less has potential for great harm.

I've never operated an airplane without the capability of removing either all or all but the very minimum of electrical power in an emergency. This was always done with switches. They practically NEVER failed because they were designed for the purpose. Same with boats. Install the proper switches to save yourself from the risk of electrical fire in the ER.

It's cheap insurance.

 

[Tom.B]

IMHO, all boats should be able to deselect all electrical power with a series of switches easily located within reach OUTSIDE of the ER. The closer to the helm, the better. Anything less has potential for great harm.


Snip-



It's cheap insurance.

Full disclosure... Unfortunately, even with all of my advocation of this, my switches are actually in the engine room and are NOT that accessible in an emergency. I do hope to change this eventually.

 

[angus99]

I put these Blue Sea remote battery switches inches away from the house and starter banks.



This was taken before they were fully hooked up.



The remotes are on the main panel near the helm where I start the engines (vs the flybridge). They're the red switches near the upper right.



Hope I never have to use them, but I can shut down the starter circuits instantly if I hear a runaway.