Improved Charging System

[erict]

I would like to improve my charging system by making it more automatic and foolproof. I have a few specific questions but also would appreciate feedback on the overall plan.

1. Add either an Echo Charge (15 A) or Duo Charge (30 A) to charge the start battery, which is a standard group 24 flooded battery. This enables charging the start battery from any of three sources: AC shore power, engine alternator, and solar. Echo Charge consumes less than 50 ma when not charging so it can be left on all the time (allowing solar to keep both banks topped off). The Duo Charge consumes 500 ma and would need to be switched off when there's less than .5 amps of charging source.

2. Wire the alternator output to house bank to eliminate chance of frying the diodes in case someone turns the 1/2/all Perko switch to off.

3. Rewire the ProStar 15 PWM solar controller. This is a smart controller/charger that varies the solar power output depending on battery charging needs and other electrical demand. Currently the "Load" terminal of the controller is the supply for my DC panel. The controller charges the house bank when solar power exceeds demand. When demand is greater, the controller outputs maximum available solar power AND draws from house. How is the "Load" terminal helpful? It seems simpler to supply the panel directly from the house bank.

4. Balmar advised switching off solar power when charging from alternator to avoid confusing the alternator regulator. I would want to automate this and thought of using a low voltage disconnect and a normally closed relay between the solar panel and controller; when there's energy coming from the alternator (or AC charger) then the relay energizes and opens the solar circuit. Thoughts?

[btrayfors]

Congratulations! I think you've got it just right.

BTW, unless you've got some unusual load on your start battery, the EchoCharge is more than up to the job of maintaining it.

Bill

[CharlieJ]

+1

Charlie

[erict]

Thanks Bill and Charlie.

Only load on the start battery will be a 1kW starter for the diesel engine. I doubt a charging source for the start battery would need to deliver more than 3 or 4 amps.

[btrayfors]

Right you are! Typically, the total draw when starting a small diesel is less than 1 AH. Maybe 150-250A for a few seconds. Most folks don't understand that, and think that their 55A alternator connected to the start battery is actually doing something!

Let us know how it works out for you.

Bill

[wolfaroo]

Originally Posted by erict

How is the "Load" terminal helpful? It seems simpler to supply the panel directly from the house bank.

Hi Eric,

I wasn't sure if you were looking for info about this or not, but in case you are...

Although my DC panel is also currently connected directly to the house bank (the same setup as you intend to rewire to), the Load terminal can be helpful: The controller will disconnect the load terminals in the case of low voltage (11.4V with reconnect at 12.6V on the ProStar15 I believe) in order to protect the batteries from deep discharge. So if that protection is useful to you, you may not need to rewire that particular connection.

I'm not sure about the ProStar but some controllers (like my EPRC-ST 10A) can also be programmed to connect/disconnect the load terminals depending on the light conditions detected by the PV panel e.g. for automatic lighting.

Originally Posted by erict

Balmar advised switching off solar power when charging from alternator to avoid confusing the alternator regulator. I would want to automate this and thought of using a low voltage disconnect and a normally closed relay between the solar panel and controller; when there's energy coming from the alternator (or AC charger) then the relay energizes and opens the solar circuit. Thoughts?

Thanks - it never occurred to me to use a relay - I have a manual isolator switch but automation will mean one less thing to forget! I am interested to know if many others have a similar setup?

Cheers,
Neal

[dupek]

I build charging system from small 99cc engine and 60A alternator. Photos at http://www.jestarkel.net/char1.JPG and http://www.jestarkel.net/char2.JPG.
It should keep my battery's "up to date". Still have to add exhaust pipe and muffler.
I figure, if I run it for a hour, it will recharge the batt banks(2).

[Adamante]

Originally Posted by dupek

I build charging system from small 99cc engine and 60A alternator.

Where on the boat do you plan to mount that?

[dupek]

(I have Watkins 27. The inboard engine was removed and outboard installed. I will put it in empty inboard compartment. Does have 2 wents.

[Adamante]

Originally Posted by dupek

(I have Watkins 27. The inboard engine was removed and outboard installed. I will put it in empty inboard compartment. Does have 2 wents.

That might be somewhat problematic. I am contemplating doing something similar, but there are some serious issues with mounting a gasoline generator inside a boat compartment.

Obviously, you have to have an exhaust system to the outside.

You must also make sure there is no ignition source on the generator to ignite any gasoline fumes. That could be any of the electrical connections unless they are ignition-proofed.

You have to pipe any carburetor venting to the outside.

You have to replace all fuel hoses to marine standards.

You have to install a fan for the air-cooled engine (or provide water cooling).

You have to establish a ventilation protocol prior to starting the engine to evacuate any gasoline fumes. Ditto after shutdown.

You have to make provisions to contain any fuel spills inside the engine compartment.

You can see that's already a fairly extensive list. There might be other issues involved, but that's what I have uncovered in my limited research so far.

[tropicalescape]

Originally Posted by dupek

I build charging system from small 99cc engine and 60A alternator. Photos at http://www.jestarkel.net/char1.JPG and http://www.jestarkel.net/char2.JPG.
It should keep my battery's "up to date". Still have to add exhaust pipe and muffler.
I figure, if I run it for a hour, it will recharge the batt banks(2).

cool setup, where did you buy the engine? What is the reduction from the alt to the engine?will it provide enough power to use an inverter continously?would a weedeater (49cc 2 stroke)engine work? Thanks Daryl

[barnakiel]

Originally Posted by erict

(...)

2. Wire the alternator output to house bank to eliminate chance of frying the diodes in case someone turns the 1/2/all Perko switch to off.

(...)

Why have the alternator wired via an 1/2/both/off, in the first place?

b.

[Lars_L]

Once upon a time I hade an idea of let nearly all charging capacity go to the house battery. But I use one solar panel to charge the motor battery. The current from the panel go through a bistable relay and a charge control to the motor battery. When the motor battery was charged the relay should shift to charge the house battery via that charge controller. I have heard a figure of 0.25 Ah for starting the engine and a solar panel would quite fast charge that. A 60 W solar panel never gives more than 5 A so the bistable relay could be quite small and hopefully have a reasonable price. So far it have stayed as an idea.

[dupek]

I purchase the engine at Harbour Freights for $109. The pulley is 2inch. I had to press on as did not wanted to slide in. It should. The alt require min 1000rpm to put some juice. The alt mounting hardware, I purchase in local hardware store. The alt was $35,but they charge me core $15. All the hardware was about $10. You need 1hp to get 60A alt working (33cc), but under some load, more hp will be nice as the engine will not have to work hard. I run the engine around 1200rpm and that is enough to charge batt. Save on fuel too. Too small engine will use more fuel and my not last long. That 60A alt will give about 45-50A (around500W). Using 1500W inverter, I will have to "borrow" some amps from batt for about 10min to make me a coffee(1200W). I consider to put 100A alt, but that will put too much load on the engine.
I am planning to put small fan in the compartment to blow out the fumes trough went holes.

[tropicalescape]

Originally Posted by dupek

I purchase the engine at Harbour Freights for $109. The pulley is 2inch. I had to press on as did not wanted to slide in. It should. The alt require min 1000rpm to put some juice. The alt mounting hardware, I purchase in local hardware store. The alt was $35,but they charge me core $15. All the hardware was about $10. You need 1hp to get 60A alt working (33cc), but under some load, more hp will be nice as the engine will not have to work hard. I run the engine around 1200rpm and that is enough to charge batt. Save on fuel too. Too small engine will use more fuel and my not last long. That 60A alt will give about 45-50A (around500W). Using 1500W inverter, I will have to "borrow" some amps from batt for about 10min to make me a coffee(1200W). I consider to put 100A alt, but that will put too much load on the engine.
I am planning to put small fan in the compartment to blow out the fumes trough went holes.

Thank you kindly..good info..DVC