Solar Power Electric Cart Battery Charging

[dgrant]

I recently purchased a 1999 Club Car Carryall II, 48V electric drive cart (see photo -yea!) for use as a utility vehicle on my farm. I do not have AC electric power at my farm (I live in town), and want to charge the cart's 48V battery using an off-grid 48V solar power installation I am installing. In reading the service manual for the Powerdrive charger, I now understand that the charging current is controlled by the cart's OBC, and that the OBC keeps track of the charging requirements. Excerpt: "The computer accomplishes this by sensing when the exact amount of energy necessary has been returned to the batteries, rather than sensing voltage, rate or change of voltage, gassing point, or any other measurement parameter."

My question: what will happen if the cart's batteries go for long periods without ever being charged the "normal" way (i.e. with the Powerdrive charger)? I am confident that the high quality solar power charge controller I have purchased can charge the batteries properly, but will the OBC still think they are discharged? Any other adverse effects I should expect?

I also intend to use the cart's batteries to run a 48V inverter to supply power to portable AC electric tools. Again, the OBC won't "know" about this drain on the batteries. Will this likely cause problems?

Dave

[dougmcp]

I don't see any reason why you can't charge and maintain the charge with a solar system.
I have friends in Mexico that have their Ezgo with a solar panel on the roof of the cart and it is never plugged into AC.
I would have to do some research on the OBC to see what it's effect is on the cart in general, other than a trouble light (battery indicator) there should be no difference.
Somewhere in the mix the batteries have to equalize and if your plan is to use the CC charger from time to time, all should work well.
It might be handy to install a voltmeter on the cart to know what you really have in stored energy.

[sonicj]

the OBC's only function is monitor usage, then to regulate the charge from the factory charger. personally, i would bypass the OBC and use a off-the-shelf solar charge regulator.

i posted a diagram on how to bypass the OBC here. link cheers!
-sj

[sonicj]

actually, that diagram isn't really that relevant. the main thing you would need to do is bypass the OBC's interlock function.
-sj

[Michael Eddie]

Nice carryall dgrant, thanks for showing!!

[dgrant]

Thanks all. for the encouraging replies.

Dave

[dougmcp]

We look forward to your progress on this solar project. Be sure to keep us posted.
These guys have a lot of useful info on solar charging and batteries, give them a look: http://www.windsun.com/

[heyubu]

I don't see any reason why you can't charge and maintain the charge with a solar system.
I have friends in Mexico that have their Ezgo with a solar panel on the roof of the cart and it is never plugged into AC.
I would have to do some research on the OBC to see what it's effect is on the cart in general, other than a trouble light (battery indicator) there should be no difference.
Somewhere in the mix the batteries have to equalize and if your plan is to use the CC charger from time to time, all should work well.
It might be handy to install a voltmeter on the cart to know what you really have in stored energy.

how big of a pannel would you need to charge a cart
would u have any idea

[gaminde]

Hi Heyubu

I have looked into this some, There are some standard house panels that will fit on the roof of most golf carts, they put out 50 to 60 volts at about 2 amps.

So it might maintain batteries while charger is not on, but it would take quite some time to fully charge them @ 2 amps.

I would bypass the OBC for the Solar Panel, Install diodes in the feed lines so when the charger is on or at night it will not feed back into the panel.

[heyubu]

thanks