Solar panel for taylor dunn cart/golf cart

[dreaming mechanic]

hello
i have a 48v Taylor dunn cart that i would like to install solar panels as a roof to charge it completly without having to charge it on the mains .I have done some researche on it and found some interesting videos and estimated that for a 6v 240ah battery it needs at least a 200w solar panel to charge it in a day .

But we don't have the original batteries so now we only have the cart and new batteries are too expensive for us so at moment i am using 4 52ah 12v car batteries . Originaly with the 240ah batteries it could go 24 miles on a single charge but with my batteries it goes about 2.3 miles on a charge which is perfect for transporting hay from our fields and stuff .So it would great to be able to charge it while i am loading it up in the fields and not polluting the air .

So i was thinking that a 405w 12v solar panel with a 48v genasun booster (like i have seen in some videos ) would be able to charge those four 52ah batteries in a day of full sun (5 to 7 hours ).

what does anybody think?
can i carry on using my car batteries ?
by the way my cart is a bo-210 taylor dunn

Thanks .

 

[dreaming mechanic]

p.s
want to do it like this video :

 

[dreaming mechanic]

what about this kit ?https://www.amazon.com/dp/B0B5WZMSXM?th=1

Thanks

 

[HRTKD]

Yes, you can use those batteries. It's not going to take you very far but you already know that.

The key here is that you need a solar panel with a voltage that if 5 volts higher than the battery voltage for the solar charge controller to begin charging. +1 volt higher than battery voltage to continue charging.

Using a random panel, the panel below has a Voc of 52.6 for the 475 watt panel. That's not good enough. I would look for a panel with a voltage of at least 60 volts. You can take two smaller panels and connect them in series to bring up the voltage. Then use a solar charge controller rated for a 48 volt battery. The Victron MPPT 100/20 will work. If ti was me, I would try to find a single panel that satisfies your requirements instead of piecing together multiple panels, just because it's easier to deal with a single panel for installation and wiring.

Maxeon 460W Mono 72 Cell 1500V SLV/WHT Solar Panel, MAX6-460-COM

With industry-leading service and equipment, Greentech Renewables helps solar contractors install top quality solar PV systems, gain competitive advantage and grow their business.

www.greentechrenewables.com

 

[Vigo]

It is doable. I too have been using car batteries in a 48v cart.

The simplest way is to find a 60v+ panel as HRTKD mentioned, and then hook that to the battery pack through a simple PWM solar controller.

The next simplest way is to use any old 30-40-something volt panel and use a voltage-boosting MPPT, to feed that to the PWM controller, to the battery. I say that because the voltage-boosting MPPTs i have seen cheaply available do not seem to also be 'charge controllers' with multi-stage charging setpoints (absorption vs float etc). But you get that function cheaply enough just by feeding the output through a PWM charge controller.

I have a 60-something volt panel i will mount as a 'roof' of sorts on my cart using a pwm controller. Just haven't done so yet. My cart needs more frame repair (rust) and i did one side and got too lazy to do the other. Nevertheless, i took my two daughters around in circles in the yard doing little wheelies with it a couple days ago, broken frame or not.

 

[dreaming mechanic]

hey
Thanks for the replys. Cool ,what about get 4 of these eco worthy 120w 12v solar panels because normaly solar panels have max voltage of 17v so with those i'd get 68v max and 480w . Here's the link : https://www.amazon.fr/ECO-WORTHY-Pa...2v+100w+panneaux+solaire,aps,152&sr=8-13&th=1

Or what about this solar golf cart kit that has a voltage boosting mppt controller and is 400w 48v :https://www.amazon.com/dp/B0B5WZMSXM?th

Sounds fun with your golf cart , i'd love to do that if this works . what wattage solar panel have you got ? and battery ah ? how long does it take to charge them ?

Thanks again guys for your replys and info , i love the ideas of not using any fossil fuels to power my cart .

Thanks

 

[HRTKD]

I have no experience with a "voltage boosting" solar charge controller.

 

[Vigo]

Im not a huge fan of the value proposition with that $400 kit but im a cheapass who enjoys the challenge of 'integrating' a pile of mismatched and used components to do something they were not really intended to do. So take my perspective with a grain of salt.

There are at least 4 or 5 voltage boosting MPPT solar controllers under ~$70 on amazon. A pwm charge controller which can handle a 48v system is under $40, a few are down closer to $20. A single used 200-something watt 30-something volt solar panel could be $50 or less unless you are paying to ship one. Granted, that's not 400w, brand new, designed to work together, but that's what i'd be doing. Maybe when you put it that way $400 for the peace of mind doesn't sound so bad.. lol

Amazon Examples:

https://www.amazon.com/ECO-WORTHY-Controller-Regulator-Lead-Acid-Batteries/dp/B0B4SL5C2X/ref=sr_1_3?crid=3A0SQKIZJQAUS&keywords=voltage%2Bboost%2Bmppt&qid=1692906709&sprefix=voltage%2Bboost%2Bmppt%2Caps%2C113&sr=8-3&th=1

https://www.amazon.com/dp/B09XB7FYD2?ref=nb_sb_ss_w_as-reorder-t1_k0_1_31&amp=&crid=191SEHKQKTSQ8&sprefix=48v%2Bpwm%2Bsolar%2Bcharge%2Bcontroller&th=1

I haven't built my setup yet so i have no results to share. But, you should be able to do the rough math based on your battery capacity. You have roughly 48v x 52ah = ~2.5kwh of battery capacity, of which you are probably using 2kwh or even less. If you take the 2000 watt-hours and divide by the watts of solar you expect to have, say 400w, then 2000wh / 400w = 5hours to charge it. If you use less than 2kwh per day you could probably get away with 200-odd watts of solar, but if you are running that thing from full to dead every day you should try to get 400+w of solar on it.

 

[dreaming mechanic]

Hey
Thanks for your reply . i was just looking for something cheaper than normal ones but now i have done more research like you saind i have it is much cheaper to buy them seperatly so waht do you of these solar panels:

https://www.amazon.fr/WilTec-Recharge-Batteries-Monocristaline-Installation/dp/B08466XD6T/ref=sr_1_8?__mk_fr_FR=%C3%85M%C3%85%C5%BD%C3%95%C3%91&keywords=12v+100w+panneau+solaire&qid=1692944059&sr=8-8

with the charge controller in your link .

I will probably use about 25 to 50% of the batteries.

That's great. i won't be using it everyday so a day to charge up plus it will be charging while i use it .

Thanks

 

[Supervstech]

Hmmm… idk for sure, but car starting batteries put in series sounds dangerous to me. Far too easy for them to get out of balance with each other and have one explode… not boom explode, just a big acid dump… of course, they can dump a ton of H2 gas out, so, if in confined spaces, boom is possible…

Are these batteries all new? Are you checking each one voltage regularly to see if any are getting high or low volts?

 

[Vigo]

Car batteries in series isnt any more dangerous than getting to X volts with any other form of FLA. They may have slightly more short circuit current potential than a deep cycle batt of equal weight, but not by enough to put them in a different category of dangerous in my opinion.

I cant see the price for those panels on French Amazon (im in USA) but i think you (OP) are already on the right track and just down to finding best prices which are very local/regional. Make sure and update with your final selections and once the ‘build’ is underway. ?

 

[Supervstech]

Car batteries in series isnt any more dangerous than getting to X volts with any other form of FLA. They may have slightly more short circuit current potential than a deep cycle batt of equal weight, but not by enough to put them in a different category of dangerous in my opinion.

I cant see the price for those panels on French Amazon (im in USA) but i think you (OP) are already on the right track and just down to finding best prices which are very local/regional. Make sure and update with your final selections and once the ‘build’ is underway. ?

Actually, batteries designed for starting have VERY little tolerance for deep discharge.
Using g them below 60%dod and the plates get damaged reducing capacity...
Then they don't recharge and they fail...

 

[Vigo]

I dont disagree that they’re non optimal but i think when you compare the cost of a basic 48v string of car or marine batteries compared to an ‘appropriate’ pack for that cart, the results you’ll get might be good enough to be considered a good value at the much lower price.

I personally have no real plans to upgrade past the 4x 27dc marine batteries in my cart, unless i modify the trays to fit 29dc instead. They have been ‘good enough’ for a long while now. Theyre definitely far down the list of repairs or upgrades mine needs. Mine has had all manner of poor braking performance, has caught fire, has nearly collapsed from frame rot, no lights, no key, etc etc. It was $250 and i am happy with it for what i have in it, and it definitely doesnt ‘deserve’ better batteries than what its got!! But taylor dunn carts are cooler than my ~89 Ezgo will ever be too, so take it for what its worth! ?

 

[HarryN]

The booster that you want is a genesun.

You will want to have the Vmp as high as possible - but - keep the solar panels Voc under 40 volts no matter what and that is a very hard limit so don't dance on the edge of it.

Max useful input is 8 amp so most likely you will need to have 2 panels and 2 controllers. It is not helpful to over current the input of the controllers, in fact it makes them go into a safety loop.

Mount the controllers on a heat spreader such as some aluminum or similar to help dissipate the heat - they will have a longer lifespan. I know they don't officially need it but it does help. It isn't very much heat but it helps the lifespan a lot vs mounting on an insulator.

Yes I use them.

Genasun – Sunforge LLC

sunforgellc.com

_______________

As mentioned by others - the conventional higher solar panel voltage array / charge controller concept also works.

 

[dreaming mechanic]

Hello
Quick question: one of my batteries terminals are really damaged . Can i use for the moment then replace it when i can ?
Thanks

 

[Supervstech]

Hello
Quick question: one of my batteries terminals are really damaged . Can i use for the moment then replace it when i can ?
Thanks

Pics?

 

[almagron]

The booster that you want is a genesun.

You will want to have the Vmp as high as possible - but - keep the solar panels Voc under 40 volts no matter what and that is a very hard limit so don't dance on the edge of it.

Just curious, why keep Voc under 40 volts? The Genasun data sheet recommends 50 V as a recommended max Voc.

(60 V is the true max input voltage but I can see why they recommend 50 Voc to account for the panel's temp coefficient & mfg variation)

 

[HarryN]

Just curious, why keep Voc under 40 volts? The Genasun data sheet recommends 50 V as a recommended max Voc.

(60 V is the true max input voltage but I can see why they recommend 50 Voc to account for the panel's temp coefficient & mfg variation)

Thanks - it looks like they have changed some of the specs vs before.

I will contact them to double check as those would be very welcome changes.

Be very cautious about going over their numbers. On the versions that I used, the excess Voc was burned off as heat and this would work for a while but eventually they would over heat and fail. On those versions, voltages higher than 40 volts were burned off, but it looks like this might now be higher.

Thanks for pointing out this change as it was a real PITA for me and I had given them some grief about it.

I have had good success with them as long as I used them conservatively. I have also burned some out when I was not.

 

[Delmar]

I did it, and I’m no rocket scientist. Not even an electrical engineer. I used four HQST 12V 100W panels in series for 48VDC. Made a PVC pipe tilt mount, and edge-bolted the panels for strength. MPPT on the underside of the roof and ran the cables down through the plastic rain channel.

The panels will charge the cart better than you expect. Currently you drive the cart all day, then charge when you return. By having onboard panels the batteries will discharge less while using, requiring less downtime to recharge when you return. Also not letting the car batteries discharge as deeply will extend their life a bit.

 

[dreaming mechanic]

Hey
Thanks for replys . delmar , your set up is so cool exactly what i want to do for mine but on a taylor dunn and using car batteries . Could you send me links to your if poss ? How fast does it charge your batteries ? How did you make your frame for tilting ?

I have got 3 12v 52ah batteries but one of them has got damaged terminals (will send pics) and i don't really want to use it cause i might be dangerous but i have a 60 ah battery . could i use that temporairaly till i can buy a new one ? will it add up the ah or will it just use the 60ah ?


Thanks for the help