Petrol Engine Battery Charger

Submitted: Friday, Jul 20, 2007 at 23:15

ThreadID: 47933 Views:5708 Replies:6 FollowUps:6

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kwk56pt

I bought a book called "Build Your Own Direct Charging Plant" by Robert Sharman available from Tasman Energy. I already had a 4hp honda on the edger so I thought with the aid of this book I could solve my power problem as I only need a solution for several weeks a year as the batteries take care of power on weekend trips.
I was disappointed with the book in the information on wiring the basically says..

"Correctly rated wire must always be wired up to meet the relevant electrical guidelines and careful consideration should be given to fusing and protecting the installed system"
and the information on regulators concludes..........

" you will need to find a knowledgeable automotive electrician who is prepared to let you study his supplies catalogues. From these catalogues you should be able to find a regulator which is adjustable and will function in a variety of ways "

I should have just gone directly to a electrician and I know ,I know I should have gone solar instead.

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Reply By: wheeleybin - Saturday, Jul 21, 2007 at 08:09

Saturday, Jul 21, 2007 at 08:09

See if you can find an old REDBACK unit (I think made in Alice Springs but stopped production about 15 years ago )that was installed on outback Telstra Vehicles.
It is a modified bosch alternator with a control box that will give you 120A of 12V charging 240V DC power and 150A of DC Welding power.
I got one and converted it with a 6HP vertical shaft Tecumseh and it has been an excellent back up.

The 240V side is OK for fillament lights ,grinders and drills without variable speed control.
ian

AnswerID: 253663

Reply By: Member - Kiwi B - Saturday, Jul 21, 2007 at 10:22

Saturday, Jul 21, 2007 at 10:22

kwk,

Sounz like the book is a bit out of touch. Most/probably all alternators from the past 20 years are internally regulated.

I've been toying with the same idea, using alternator to match vehicle so there's always a spare available. Got filed away in too-hard basket and bought Honda 10 gene. Still carry spare alternator tho as I wouldn't like to be caught with a dead one a few hundred k's from town.

Yip, solar is good but not so clever when the sun don't shine. Seems to be these sorta days that ya hang around camp using electric gizmos too.

Good luck building,

AnswerID: 253681

Follow Up By: kwk56pt - Saturday, Jul 21, 2007 at 11:16

Saturday, Jul 21, 2007 at 11:16

The regulator is a issue because most alternators put out 14volts roughly and it needs to be regulated higher for quicker battery charging but I ended up with a new bosch that is already regulated to 14.7 volts.
I only need the unit for a few weeks camping a year and using the edger motor seemed like a cheap way of solving the problem. It only needs to run about 45 mins a day which is attractive.
If this all works out I might get a small solar panel that could finishing charging the battery after the alternator has put in the quicker bulk charge as fully charging takes a lot longer.
The intent of my post was to make others aware that the book isnt a complete manual and you will still have to seek professional assistance and if you are happy with this buy the book as it does have some worthwhile information but as I said lacked the key answers I was looking for.
I did find that the A section pulley on the alternator is automotive and only industrial pulleys are available for the honda 3/4 shaft. Yes they run different belts so you need to have one pulley machined so they bothe run the correct belt. It seems easier to source a selection of short industrial belts than automoyive one so I had the alternator pulley made to match the industrial one on the honda

FollowupID: 514746

Follow Up By: Mike Harding - Saturday, Jul 21, 2007 at 11:21

Saturday, Jul 21, 2007 at 11:21

If you have a gen with you a dead alternator isn't too much of an issue; just keep driving until the battery falls to a low level (9 or 10V) and then stop and use the gen to recharge the battery. Repeat until you reach help.

Mike Harding

FollowupID: 514749

Follow Up By: Member - Kiwi B - Saturday, Jul 21, 2007 at 11:46

Saturday, Jul 21, 2007 at 11:46

Mike,

Understand what you're saying but night driving aint gunna get far and puddling around with gene would pee me off. Trip last year was 5 months and wouldna liked to have shortened any of it for minor failures

FollowupID: 514752

Follow Up By: jeffwa - Sunday, Jul 22, 2007 at 00:56

Sunday, Jul 22, 2007 at 00:56

Night driving? Sleep in the car or setup camp and drive during the day?

I'd rather stop for smoko a few times to charge the batteries than change the alternator on the side of the track. ;-P

FollowupID: 514850

Reply By: Member - Kiwi B - Saturday, Jul 21, 2007 at 11:42

Saturday, Jul 21, 2007 at 11:42

kwk,

This could possibly lead to a fairly lengthy discussion around a campfire but I've seen the Patrol delivering 50 amps @ 14.2volts to a pretty flat battery. Not sure why it would want any more.

Have solar panel also, but in the warmer weather, 38 deg+ it just weren't cuttin' the mustard. Fridge working harder and solar going on holiday coz've heat.

Yer right about the auto-section belts, it was obviously too difficult to standardise belt sections a few years back.

AnswerID: 253685

Reply By: Member - Phillip S (WA) - Saturday, Jul 21, 2007 at 12:02

Saturday, Jul 21, 2007 at 12:02

When I was recently at middle lagoon W.A. I ran my engine for half an hour in the morning and 1 hour in the afternoon to top up my battery as I run two fridges and lights......worked great....did not need a generator or solar panel....diesel used...hardly noticed, uses very little on idle....and for you critics I kept a graph, volts/time with a digital multimeter, so I know the levels were being maintained....Phil

AnswerID: 253689

Follow Up By: jeffwa - Sunday, Jul 22, 2007 at 00:59

Sunday, Jul 22, 2007 at 00:59

That's what I normally do. Be a different story in one of those comunal type campsites I guess, but I don't camp near anyone else so meh.

If I had a Genny I would:

1. Have to buy it = $$$
2. Have to carry it = Don't have enough space as it is.
3. Set it up and carry and extension cord = more space and friggin around.
4. Carry ULP/Two stroke = more space, PITA, smelly.

Meh, just run the 3.0L turbo charged genny under the bonnet. LOL.

FollowupID: 514851

Reply By: Member - John - Saturday, Jul 21, 2007 at 13:49

Saturday, Jul 21, 2007 at 13:49

kwk, what you need is called a "taxi regulator". Has a link that can be switched to go from normal charging, 14.7, I think, to boost charge, 16 volts. Hope this helps. John