Father-Son Solar Golf-cart build

[DENWA]

Been thinking about this since my son was captivated by Will's video.

Last night I bought a 2008 Yamaha YDRE (Drive?) cart in good shape but the batteries are bulged and need of replacement for $1500.

Yamaha is a 4s 12V battery configuration to make 48V.

Then I ordered 4 of these HiQ 12V 100 Ah on eBay for $259 each. https://www.ebay.com/itm/275526022953 They say they can be up to 4s4p we will see if they can handle the first decent hill or do they end up for storage.

Here's the plan: My Son's doing all the work. He's 10 and VERY eager and I'm a little scared he has too much faith in the Solar working... The budget from here on out is below $800 for everything, which he must keep detailed track of. He can salvage anything and sell parts/lead acid batteries etc. to get extra money but my goal is to get him thinking.

Questions:

1. I watched Wills video last night on the Boost MPPT does anyone have experience with these? Are they reliable in a golf cart that could see rain? Any brands better than the $69 dollar ones off Amazon? I wish @Will Prowse would give an update on his setup as I see he's gone with a Solar trailer, wondering if rooftop is not enough.

2. Panels for roof: I have 2 options available to try: 2 grape solar 180W ( 24V OCV/18V Mppt) at 26"x57" or 1 Santan 60 cell 245W (37V OCV/30VMppt) 39" x 65" haven't measured the roof to see what will fit but both are voltage too low to charge the 48V packs. Any experience or knowledge here?

3. I'd like to be able to take this to our place in WV which is not flat. Never messed with electric before so we will see if it as enough ground clearance or stamina to climb the hills.

 

[DENWA]

here are the pictures!

 

[littleharbor2]

Possibly you could locate some 72 cell 175 - 185 watt panels. Some used Sunpower 220 watt panels are similar size
. They tend to be around 32" x 65". Two in series will give you 48 volts nominal voltage. This is the smallest configuration giving decent output I can think of. Don't expect any rapid charging with this configuration but given the limited space available that is about the best you'll get. Maybe you can get creative with the mounting so as not to be sticking out so much beyond the roof lines. Definitely have some form of plug in charger if you don't already as this is where the bulk of your charging would have to come from.

 

[DENWA]

We measured the roof this morning:

Top is ~65"x45" and the Frame that holds the top is ~39"x51"

Doing the research on what the options are to purchase a panel but otherwise I'm thinking the 2 grape solar 180W we have with a boost controller might be the way to go.

Also has anyone tried one of these balancers for 4x 12V?

https://www.amazon.com/Fdit-Equalizer-Balancer-Lead-Acid-Batteries/dp/B084NYBZSP

 

[Delmar]

Great project! The HiQ batteries seem too good to be true, please keep us posted. Edit: my cart draws ~130A while accelerating or climbing hills. the battery 100A max discharge may pose a problem.

Also have a Yamaha AC motor cart where the battery set powers my 48V UPSverter and back-feeds my breaker panel during grid down. However my cart has six 8V batteries.

I edge-bolted four HQST 100W 12V nominal solar panels with PVC pipe tilt-mount to get sufficient voltage. They hang over the roof about 6” but is not really a head-knocker. More than enough power to keep the cart charged, and supplements during grid down. You can read more about my conversion here.

 

[jberger]

Just an FYI, the BMS on those batteries is going to limit your starting and hill climbing since it's just 100a.
Don't try to stop and start on a hill and you should be ok.
You need to work out a way to "restart" the batteries when the BMS turns them off in these situations. Even if just one of the BMS's were to trip into protection, you would be stuck since you need all 4 working to get 48V.
In some cases you just need to turn off the load for a specified period of time, in other cases you might need to apply a higher voltage (like a charger) to get the BMS to turn back on.
I'm just trying to call out what might get you stuck, so you can test and plan BEFORE that happens.
Sounds like a great project, have fun!

 

[DENWA]

Updates:

1. replaced Pb acid with 4 x of the HiQ batteries $259 each. They were so small the standard battery hold downs were way too big--My initial review of them on this forum. https://diysolarforum.com/threads/h...-store-my-initial-thoughts.52921/#post-674866

2. Added an active battery balancer for $50 off of eBay but the batteries haven't needed them so far!

3. 450W ECO Worthy Boost controller-- Not had enough sun yet but so far I'm not impressed $60 on eBay

4. 2x 120W( 28V OCV) Flexible soldier portable solar panels. The 150W will fit but the 180W were a little too long and hung off the front. --These are panels we make at work and are not available to commercial market. The grape solar were perfect voltage wise but just too big as I confused the dimensions.

Tomorrow we will update panels with a PVC Frame and of course clean up the wiring a little.

 

[DENWA]

Oh yes my son wanted to point out the cell phone holder!?

 

[OzSolar]

This is great. I never found a project I could get my kids involved in and I tried them all. You've got yourself quite a victory there whether you realize it at this moment or not.