Gas Engine Driven Battery Charger

[RaymondR]

In 2016 I needed to move a newly purchased Island Packet 40 from the town of Busseltown on the SW corner of the Australian continent around the northern coast to south Queensland on the east coast.

It being an almost 4,000 nm coastal voyage I decided to purchase a small portable genset for emergency battery charging and consequently, being in a place without any sort of Honda agency ended up with a Yamaha 1000 watt inverter generator. This thing has turned out to be the bane of my life and I was about half pleased when it quit working. It has been such a frustrating piece of equipment that I am not going to pursue any warranty repairs and will junk it.

In order to have an emergency charging facility I have used an electric start, 5 hp gas engine to belt drive an 85 amp Bosch alternator on one side and a 120 amp Chinese alternator on the other.

I had originally intended to direct couple a 200 amp alternator but as the engine already had a double V belt pulley on it, I already had the 85 amp alternator and a spare, and I have two battery banks, one AGM and a LiPo it appeared a good plan to be able to assign an alternator to each and charge them at the same time.

Since it is a gas engine I wanted it enclosed in a metal enclosure and will clothe this is noise dampening foam inside a second glass covered plywood box.

The first image shows the engine from the pull cord and starter panel side, mounted in the spill containment tray.

The second image shows alternators and motor from the drive side.

The third image shows the metal enclosure on the unit.

[RaymondR]

The Electrical Arrangement.

Having pretty well finished the mechanical work I now need to address the electrical circuits.

I could install the charger in the lazarette however ir would pretty well take up all the room in there and be difficult of access. Consequently I have decided on deck mounting. It's a fair lump of an object however sacrifices must be made in order to pursue the cruising lifestyle.

Since I don't particularly want to have to go on deck to start and shut down the engine I will be duplicating the control panel down below. I'm investigating doing this using solid state relays. The existing AC battery charger connects to the two battery banks using Anderson connectors and I will tie the alternators into these connections.

The vessel already has a 2,500 Watt mains power inverter and I intend to crank up the engine driven charger to prevent battery draw down when I use it.

Future ambitions include a high pressure RO pump and perhaps an auto aircon compressor.

[smac999]

Using The Yamaha is already ghetto.

This is super ghetto,

[Mr B]

I bought this from a local 4x4 company that gets them made in China,
$400-00 Delivered, 40 Kgs, So its light enough to lump around,
Its not bad on the noise either,
It has 2 x 240 outlets and a 12 volt battery charger inbuilt,
Pull start, usually first go,

Yours isnt bad either,

[wsmurdoch]

This is a similar build of a home made gasoline engine driven auto alternator used as a battery charger. It uses a weed eater engine.

https://www.youtube.com/watch?v=IbVFH_vg2fw&t=1s

https://www.youtube.com/watch?v=3qSAtPDWEjE

[GordMay]

Originally Posted by Mr B

... It has 2 x 240 outlets and a 12 volt battery charger inbuilt ...

8 Amp (12V), probably an unregulated power supply, not charger.
You'd be better off powering your boat's smart charger from the 240V AC outlet.

[Mr B]

Originally Posted by GordMay

8 Amp (12V), probably an unregulated power supply, not charger.
You'd be better off powering your boat's smart charger from the 240V AC outlet.

8 amp x 12 volt is what it puts into the batterys, Its a dedicated battery charger,

Its made specifically for off road 4 x 4 use here, And they are quite popular, They sell lots of them,
Very good reviews on the 4x4 forums as well,

4x4's are offroad cars and trucks,
Registered four wheel drive vehicles that are 100's of miles from nowhere, With a flat battery or batterys, You can die very quickly in isolated areas here,
You cant walk 200 miles in 40 degree Celcius heat to get help,
A lot of inland Australia is arid desert, And no people any where,


How do I use the onboard 240 volt AC outlet when my batterys are flat,

The reason I bought this one, As a back up,
Just in case my batterys are flat, No Sun, No solar, Flat Batterys, No power, No Engine, No Invertor, No nothing,

[Sailmonkey]

Originally Posted by Mr B

8 amp x 12 volt is what it puts into the batterys, Its a dedicated battery charger,



,

It’s not a charger. Let’s call it a power supply for clarity.
If your concern is flat batteries it’ll certainly bring the voltage up enough to allow the 240v mains charger to pickup though.

[Mr B]

Originally Posted by Sailmonkey

It’s not a charger. Let’s call it a power supply for clarity.
If your concern is flat batteries it’ll certainly bring the voltage up enough to allow the 240v mains charger to pickup though.

You can call it what ever you like, Bowl of goldfish even,

The 240 volt side is a power supply, For clarity, It runs my 9 inch power saw and my 5 inch grinder at the same time, I tried it,

From the 12 volt output,

The red lead goes on the positive side of the battery, Crocodile clip.
The black lead goes on the negative side of the battery, Crocodile clip,

Couple of hours later, I have a fully charged battery,

And Wow, Unbelievable, Golly Gosh, Ill be damned, It even stops charging when the battery is fully charged,
It automatically shuts itself off,
If thats not a battery charger, I dont know what it is,
And I have tried that too, I charged a battery with it,
I do like things that work, Thats also why I test them,

I do have a 240 volt battery charger as well, It plugs into the 240 volt outlets on my 3.5 KVA generator,

For your information, I dont have a 240 volt mains charger,
Is that some thing you have in a Marina, ?????????

A 300 mile long, 240 volt mains extension cord, Just doesnt do it for me,

[Pete7]

Steady, people are trying to help you.

Have you measured the voltage output of the 12v side? because you will probably want 14.6-14.8v depending battery type and there is a big difference from 12v for charging a battery.

You said: "I do have a 240 volt battery charger as well.... For your information, I dont have a 240 volt mains charger".

It's the same thing as well you know, so plugging a mains voltage battery charger to the 240v supply will be much more efficient way of charging batteries.

Pete

[Sailmonkey]

If you think an 8 amp charger is fully charging your battery in a few hours you’ve got woefully undersized batteries, or just don’t want to learn anything.

Good luck, you’re going to need it.

[Mr B]

Originally Posted by Pete7

Steady, people are trying to help you.

Have you measured the voltage output of the 12v side? because you will probably want 14.6-14.8v depending battery type and there is a big difference from 12v for charging a battery.

You said: "I do have a 240 volt battery charger as well.... For your information, I dont have a 240 volt mains charger".

It's the same thing as well you know, so plugging a mains voltage battery charger to the 240v supply will be much more efficient way of charging batteries.

Pete

I said, I dont have mains power, That stuff that comes out of a Marinas power supply,

This is my 240 volt battery charger, which plugs into my Generators 240 volt side, But I dont use it ,

My generator works and it charges my batterys from the 12 volt side,
Very efficiently as well,
Whether you believe it or not, I dont care,

I was only giving the original poster info on my generator, Nothing more,

[Pete7]

Originally Posted by Mr B

I dont care,

Clearly, but you are likely chronically under charging your batteries using 12v or having to run the generator far longer than if you used the mains voltage charger at 14.6v on the generator to charge the batteries.

Pete

[billknny]

Originally Posted by RaymondR

Since it is a gas engine I wanted it enclosed in a metal enclosure and will clothe this is noise dampening foam inside a second glass covered plywood box.

Are you sure that thing will be able to cool itself in that insulated box?

Those little engines throw out an enormous amount of waste heat, and are designed to operate in free air. Throw in a couple big alternators working hard, and I see a serious "thermal problem", up to the point of being dangerous.

[slug]

Originally Posted by Mr B

You can call it what ever you like, Bowl of goldfish even,

The 240 volt side is a power supply, For clarity, It runs my 9 inch power saw and my 5 inch grinder at the same time, I tried it,

From the 12 volt output,

The red lead goes on the positive side of the battery, Crocodile clip.
The black lead goes on the negative side of the battery, Crocodile clip,

Couple of hours later, I have a fully charged battery,

And Wow, Unbelievable, Golly Gosh, Ill be damned, It even stops charging when the battery is fully charged,
It automatically shuts itself off,
If thats not a battery charger, I dont know what it is,
And I have tried that too, I charged a battery with it,
I do like things that work, Thats also why I test them,

I do have a 240 volt battery charger as well, It plugs into the 240 volt outlets on my 3.5 KVA generator,

For your information, I dont have a 240 volt mains charger,
Is that some thing you have in a Marina, ?????????

A 300 mile long, 240 volt mains extension cord, Just doesnt do it for me,

Skip the 300 mile power cable and shift to di lithium crystals

Plenty of power, long lasting and cheap as chips