12 V stand alone battery idea

[BumbleBee]

Hey guys. I know that adding a stand alone 12 V is not a new thing in the carts but I have been thinking about a twist on the idea. I have a Melex with a shaft stub on the back side of the motor that on some models were used for a drum brake. My idea is this, bolt on a pulley and then fab a mount for a GM 1 wire alternator connect the 2 with a belt and run the wire to the battery. The reason I am thinking this is I plan to have alot of load on this battery with the lights, radio, amps, horns etc, I just want to keep it charged up as much as possible. Is there any reason why this would not work or a reason not to do this?

I open the floor for discussion.

Thanks

[e-z-go1988]

That would certainly work but you would be pulling power from your main pack and reduce your run time. I am coping with the additional 12v usage by adding another 12v battery in parallel with the one I use for accessories now. Its in the bagwell.
Dennis

[gornoman]

Automotive alternators cause quite a bit of drag to accomplish their task. So much drag that Mercedes Benz has just developed an alternator that clutches out during WOT so as not to drag the engine down at all. Once the car is cruizing the alternator clutches back in. This is on a 550+ HP engine. If it's THAT important with all that power, just imagine what would happen to your 2 HP electric motor.

[BumbleBee]

Thanks for the info guys. I didn't think that the parasitic power loss from just the alternator would be that much but i guess it can be. I will have to explore this a little further after I get the motor rebuilt over the winter. It sounded good in theory.

[Pembroke36]

Yes, an alternator that is producing enough amps to recharge is a huge load. To produce electricity takes a lot of power. That is why we are stuck on hybrids with a gas engine. You would use more electricity to power a generator than it would produce. Put a slim solar on your roof to help trickle charge during the day. BTW, I am a tech at a Mercedes dealer. Besides the alternator, there is a whole system that monitors the charging system that will always keep the alternator load at a minimum for emissions reasons.

[arcitech]

One other problem with the 1 wire alternator is that it doesn't start charging until it hits about 2000 RPM, that is why a car pulley is small on the alternator and big on the crank. An auto engine has to hit about 800-1000 RPM before the 1 wire will kick in and start charging. An if you have a full load on the alternator it can take up to 24HP just to keep turning it!

[redriderno22]

you could accomplish the same thing with a small 12 volt perm mag motor and a diode

your not going to get the wattage of an alternator, but enuf juice to top off a battery depending on how you set it up

[GhostRider1]

i am new to the cart thing but i do know a bit about old trucks.. i put an altenator (second one) on an old 4 cyl car with no much power so i actually set it up to only pull when accelerator was not pressed to floor... that way it worked mostly on the down hills lol savng my main power for climbing.. done with a pressure switch toggle type kickout on cable at carb .. couldnt tell it messed with operation of throttle after i put a next size up spring on it.. just a thought

[BlackHornet]

the easiest and best bet is to just do the 2 batts in parallel...if they are deep cycle batts then that should be plenty of juice to withstand a great load and then when those batts are low...just plug them into a 12v car charger. they make battery boxes with positive and negative terminals on the lid so you dont even have to open up the boxes to charge them. if you got two of those boxes then it would take all of about 20 seconds to hook a charger up to them.

[rabbitreborn]

or you can mount a small solar panel to the roof of your cart and let mother nature recharge that 12v battery for you.......