Battery Charging from Motor

[Red_Nut]

Team,
Ihave had a look through the archives but couldn't find this question anywhere.

I have just bought a 4.2 Dory with a 2000 Merc 30. I want to look at setting it up so that the motor charges the battery (for the sounder / lights / etc). Is there any way of doing this without expensive mods?

I would like a solution that I can work through myself.

Any suggestions would be appreciated.

Cheers.

Ed.

[finga64]

If the motor is electric start it's no worries.
If it isn't and the motor doesn't have a charge coil (it may only be a lighting coil)and regulator/rectifier then it is a little worry.

[Red_Nut]

Finga,
what should I be looking for on the motor? What would a charging coil look like?

The motor is not electric start, so I may need to look at sticking with current methods (battery charger on 240v.

Cheers.

Ed.

[sf17fisherman]

ed the only way you can do it is to buy the chargeing kit and rectifier but thats a shop type of job and the parts alone cost a fair bit
even with that done your not throwing out that much of a charge so while it helps you still may need to charge it at home from time to time

ps i have the same set up in my bass boat for my twin sounders and other electronics and the rectifier makes the battery last about three full days before needing a full charge

[baldyhead]

I have a 25 yammy and from the lighting coil (the 2 green wires) I run from them to this Dick Smith Bridge Rectifier( described below) on the AC side and then from the DC side I run to my battery with a 10 amp fuse on the positive side. At idle or trolling speed the output is neglegible but for 1/2 throttle or WOT it charges the 12v 25AH battery very well. I actually only charge the battery every 3 days or so ( on extended trips) as it tends to overcharge the battery if hooked up all the time.
Go to an outboard mechanic and ask which are the two lighting coil coloured wires and hook this up as its simple. Just mount the rectifier somewhere to the motor frame to allow adequate cooling.(they don't run all that hot either).
I have used this system for about 20 years now without any problems.
One caution though...DO NOT LET the bare DC terminals short out if the battery is not hooked to the rectifier. Mine are insulated and are put into a makeshift holder when not in use.
Don't let anyone tell you that you cannot run the motor without the battery connected with this system....bloody poppycock !!!

Device: FB5006
Function/Type: 50A 600V High Surge Current Bridge


Cat No. Z3350
Category: Rectifiers - Diode and Bridge

$19.48 ea.

I know quite a few fishers with the same setup and its a cost effective way of charging your battery whilst running.
Have fun cheers baldy

[Spaniard_King]

Baldy [smiley=thumbsup.gif]

Just be aware some ac lighting modules run 3 wires from under the flywheel

Garry

[finga64]

Baldy has described the "little worry" to a tee. That's what I have and works a treat.
Is that a Merc merc or a Tohatsu merc?? If it's the Tohatsu it should have 2 green and a black wire.

[Red_Nut]

Guys,
thanks for this. This is the type if info I was asking about. Now it is time for me to do a bit of searching on my motor to find the wiring you guys mention.

Thanks for the hints. I will ask more questions if I have trouble with it.

Cheers,

Ed.

[mrobbo]

I want to do the same with my boat however my motor is a 25 Honda manual start which has a wired plug (2 wires) obviously for this purpose, connected to what appears to be a gen/alternator. My question is, do I need anything such as fuses between the motor and battery? Will charging my battery while idling/trolling affect my sounder? I then want to hook up a marine cig lighter socket/nav.lights/small fluro. I believe I should run wires from battery to bus board then to switches, then to object. Am I right in assuming that each line from switch to object should have an inline fuse, or should the fuse be between the switch and bus board. Thanks in anticipation of your help. Mike.

[Spaniard_King]

Mrobbo,

The plug on your Honda needs to be wired up straight to the battery, there is an inline fuse under the cowling to protect the wiring so none is required between engine and Battery.

Yes you should fuse each electrical item idividually weather thats before or after the switch is up to you also I would fuse the main bus bar with something around 20 amp and use 4mm tinned wire to the bus bar.

cheers

Garry

[mrobbo]

Garry, thanks a lot for that info. What amp wire should I use, I think the Honda produces 6 amps of charge. Would 15amp throughout suffice? Mike.

[Spaniard_King]

Hi Mike,

if you are going to ask for wire ask for 4mm (wire is rated like that) otherwise if you have a source anything that will cary 15amps should be fine.

Garry

[mrobbo]

Thanks, Gary, electrics are all greek to me....Cheers, Mike.

[finga64]

Mike,
If electrics are all geek you shouldn't try things yourself.
It's so easy to blow something up and that's when the bucks are spent getting new bits. I'm a sparky by trade and I know from experience
If not sure get someone to do it for you is the best motto .
blown rectifier=$100+
blown sounder=$big bucks
blown gps=$big bucks
getting someone to do the job=$not so big bucks

[ahoj]

first sensible thing i heard you SAY Finga Cheers must be sober now he he

Ahoj