Is it practical to use golf carts with a large 15KWh batteries in a home Hybrid Solar system?

[MCJEFE]

I have an unusual question.
Is it practical or even possible to use several very large, 10-15Kwh, 16S LFP golf cart batteries (that I built) interchangeably as part of a Hybrid Solar power system?

My goal would be to both charge the golf cart batteries, and to use the batteries, if not being driven as the energy storage component of a Hybrid Solar system.

I've already made 4+ golf carts with very large LFP batteries, that have Anderson connectors attached. We are typically using only 3 of the carts on any particular day leaving the 4th, usually a 6 person limo cart with a 15KWh battery, sitting idle.

The batteries I made for the available carts are as follows:
a 16S 202ah (51v), a 16S 280ah (51v), a 16S 304ah (51v) and a 24S 202ah (76v).

I live in central Florida with lots of sunshine and lots of batteries already I'm my garage...

Any advice is always.

Thanks!

 

[45North]

Do you want to power your house with them?
Like V2H, or should I say G2H.

 

[timselectric]

It's a perfectly good idea.
Put those batteries to work.

 

[MCJEFE]

Do you want to power your house with them?
Like V2H, or should I say G2H.

That was my thinking.
Currently, I am 100% grid reliant and I'm considering adding solar for emergency backup. But with 40KWh (in three separate 16S batts.) storage capacity already sitting in my garage it got me thinking about the possibility of building a hybrid solar system that would allow for charging of any of the carts batteries as well as allowing any of the carts batteries to power the house as needed. Ideally the grid would only be used to supplement if needed.

 

[timselectric]

That's what I would do in your situation.
The battery is the most expensive part of a system.
You're already ahead of the game.

 

[MCJEFE]

Do Hybrid Inverters allow for plugging and unplugging of different batteries from the system without changing settings on the inverter?

 

[ChrisG]

I set something up similar a few years ago with FLA batteries in my ClubCar. Just used some heavy Anderson connectors to disconnect the cart from the the other packs. Worked great.

 

[timselectric]

Do Hybrid Inverters allow for plugging and unplugging of different batteries from the system without changing settings on the inverter?

Any battery inverter will work, fine. As long as you don't use closed loop communications.
Do you need a hybrid? Are you planning to export to the grid? If not, I wouldn't spend the extra money for that feature.

 

[MCJEFE]

I set something up similar a few years ago with FLA batteries in my ClubCar. Just used some heavy Anderson connectors to disconnect the cart from the the other packs. Worked great.

I already use Anderson connectors on all the packs I build.

 

[exmarkretired]

Like the idea. Considering the same, as it would also help justify purchasing a golf cart. Any concerns I should be aware of ? i.e. How would you handle connecting batteries with different SOC ? Large resistor to limit current ???

 

[jberger]

They don't need to be the same SOC to connect, they just need to be the same voltage.

 

[Delmar]

I already do this with the unknown-age FLA batteries for grid-down power. I back-feed my breaker panel that is conveniently located in the garage.

 

[exmarkretired]

They don't need to be the same SOC to connect, they just need to be the same voltage.

Apologies, I should have written voltages.

 

[Barbar0ssa]

I already use Anderson connectors on all the packs I build.

I know this is an old post but your battery packs are a work of art!

 

[Vigo]

How would you handle connecting batteries with different SOC ?

It was already pointed out that similar voltages within a tenth are probably no cause for concern. BUT already at two tenths, depending on the wire in between, you might get some serious currents. I would say the only SAFE but passive/'dumb' way to handle that is to size your pack leads/connectors for the large currents you might get. I can't ID the bigger andersens with my eyeball caliper, are those the ~175a size?

I hooked a ~13kwh lifepo4 to a large lead acid bank at a much lower voltage but the crappiness of the conductors between throttled it down to a measly 80a or so. If you have large low resistance paths between the paralleled packs they really need to be sized for the possible currents (and perhaps they already are?).

 

[n2aws]

I kinda like this idea. I wonder if I could buy a golf cart, convert it to 48v, and then buy 2-3 more of my current batteries to use in it.

 

[Delmar]

I kinda like this idea. I wonder if I could buy a golf cart, convert it to 48v, and then buy 2-3 more of my current batteries to use in it.

Almost all modern carts are 48V = six 8V lead batteries. My Yamaha AC motor cart is. Electrical inspector is in the background.

 

[Vigo]

If a cart is already 48v that's all well and good, but what i did was take a 36v cart with a mechanical speed control (no electronics, just puts large resistors in series with motor based on pedal position) and fed it 48v. That combined with larger diameter tires means it will now, just barely, do wheelies. It does better wheelies if you are going uphill, have cargo in the back, or slam yourself backwards in the seat while flooring it.

 

[JoeHam]

That combined with larger diameter tires means it will now, just barely, do wheelies. It does better wheelies if you are going uphill, have cargo in the back, or slam yourself backwards in the seat while flooring it.

Pictures please !

Bonus points for a video ?.

 

[Barbar0ssa]

If a cart is already 48v that's all well and good, but what i did was take a 36v cart with a mechanical speed control (no electronics, just puts large resistors in series with motor based on pedal position) and fed it 48v. That combined with larger diameter tires means it will now, just barely, do wheelies. It does better wheelies if you are going uphill, have cargo in the back, or slam yourself backwards in the seat while flooring it.

I was running like that with a 80s EZGo Marathon. I was terrified that the resistors would become a fire hazard at the increased voltage!

The wheelies are terrifying on a 3-wheeler!