Off Grid Golf Cart Charging Station

[Alex_alvar]

I am trying to design an off-grid golf cart charging station. I am using PVsyst to help me design the system. My preference is not to add batteries to the system
The load:
(8) 6v battery trojan t-105
It connects to 220v AC source
The car has an onboard AC/DC charger
I will be using around 12 PV 300 watt solar panel and 3kw inverter with AC input range from 120
My questions are :
1- I would assume the inverter will regulate the voltage to 230vac but the current will drop when a cloud pass by. Will that affect my load? Do I need a battery to buffer and regulate that?
2- Which kind of inverter I could use? I am using Symo 3.0-3-S which is a grid tied inverter
3- What happen if I connect my load after 4pm when the output of the solar panel around 500 watt, will I be able to charge my golf cart on a slower rate
I would like to hear your thoughts. Thank you

[LETitROLL]

Get a good Solar charge controller that will charge a 48v battery directly, no need for the inverter or the onboard charger, much simpler.

[Mike90250]

Do you have Grid Power nearby ?

Do you Golf at night ?

Batteryless AC inverters, only exist for Grid Tie systems

You can charge a golf cart with DC directly to the batteries from a MPPT solar charge controller. But only in the daytime (10am-2pm)

12 panels * 300w =3600w / 56v = 64 charging amps

If you have a fleet of carts, each one gets a $500 charge controller installed, and an Anderson 100 connector.
Drive the depleted cart into the 12 panel solar carport and hook up the connector to the PV. Wait 6 solar hours and drive a filled up cart away

[Alex_alvar]

Do you have Grid Power nearby ?

Do you Golf at night ?

Batteryless AC inverters, only exist for Grid Tie systems

You can charge a golf cart with DC directly to the batteries from a MPPT solar charge controller. But only in the daytime (10am-2pm)

12 panels * 300w =3600w / 56v = 64 charging amps

If you have a fleet of carts, each one gets a $500 charge controller installed, and an Anderson 100 connector.
Drive the depleted cart into the 12 panel solar carport and hook up the connector to the PV. Wait 6 solar hours and drive a filled up cart away

I believe there are new inverters which have energy management system which has zero current injection check this one: UNO-DM-3.3/3.8/4.6/5.0-TL-PLUS-US
I believe i can use it without a grid.

I like your idea of using charger controller, i thought about it but i am not sure how i am gonna achieve that, i am an electrical engineer but i am not an expert installation guy.
Will you please explain how would you connect from the charger controller to the batteries , how would you bypass the current on board converter.
what i understood so far, you would want me to attach the charger to the car then somehow run a wire to the batteries terminals which i am i am afraid will leave some wires exposed.

***12 panels= 3600/48 = 75 , i am not sure why you divided by 56

I really appreciate your input!

[ButchDeal]

I believe there are new inverters which have energy management system which has zero current injection check this one: UNO-DM-3.3/3.8/4.6/5.0-TL-PLUS-US
I believe i can use it without a grid.

You believe wrong!
That is not what zero injection means.

I like your idea of using charger controller, i thought about it but i am not sure how i am gonna achieve that, i am an electrical engineer but i am not an expert installation guy.
Will you please explain how would you connect from the charger controller to the batteries , how would you bypass the current on board converter.
what i understood so far, you would want me to attach the charger to the car then somehow run a wire to the batteries terminals which i am i am afraid will leave some wires exposed.

There are battery connectors that can safely be used but yes you would connect the charge controller to the battery directly.

[Alex_alvar]

You believe wrong!
That is not what zero injection means.




There are battery connectors that can safely be used but yes you would connect the charge controller to the battery directly.

I live in a country where net metering is not yet established. what makes me wonder is i know plenty of projects where they installed over 20kw solar system and they installed like manual transfer switch. the project feed air condition loads and lighting. they used a normal grid tied inverter. they didnt use any kind of batteries i wonder how did they achieved that.

to conclude again, i guess i will install a charger controller by the carport area, and then i will run wire directly to the batteries positive and negative terminals with the connectors. I am just thinking how can i make it looks genuine not having random wire coming out without outlet and sockets.

I appreciate your response

[ButchDeal]

I live in a country where net metering is not yet established. what makes me wonder is i know plenty of projects where they installed over 20kw solar system and they installed like manual transfer switch. the project feed air condition loads and lighting. they used a normal grid tied inverter. they didnt use any kind of batteries i wonder how did they achieved that.

Zero injection or grid zero does NOT mean that you can operate without the grid. It means that you have a grid tie inverter that will regulate its output such that it does NOT feed power back to the grid. This is simple. Working without the grid is complex and requires a different type of inverter.

" and they installed like manual transfer switch." Are you sure about that?
Are you sure it isn't a manual disconnect which is required by code but does not allow a grid tie inverter to operate without the grid either.

To operate without the grid you need a bimodal inverter and batteries. You do NOT need a manual transfer switch, you do need a manual AC disconnect in most place to meet code though.

to conclude again, i guess i will install a charger controller by the carport area, and then i will run wire directly to the batteries positive and negative terminals with the connectors. I am just thinking how can i make it looks genuine not having random wire coming out without outlet and sockets.

I appreciate your response

use something like an Anderson power connector

[Alex_alvar]

Zero injection or grid zero does NOT mean that you can operate without the grid. It means that you have a grid tie inverter that will regulate its output such that it does NOT feed power back to the grid. This is simple. Working without the grid is complex and requires a different type of inverter.

" and they installed like manual transfer switch." Are you sure about that?
Are you sure it isn't a manual disconnect which is required by code but does not allow a grid tie inverter to operate without the grid either.

To operate without the grid you need a bimodal inverter and batteries. You do NOT need a manual transfer switch, you do need a manual AC disconnect in most place to meet code though.



use something like an Anderson power connector

Is it possible to connect to the grid using zero injection inverter, in a country that does not have net metering system? just to get the benefit of having the grid as backup

[ButchDeal]

Is it possible to connect to the grid using zero injection inverter, in a country that does not have net metering system? just to get the benefit of having the grid as backup

YES but you don't have the grid as a backup since solar is NOT the primary power source. You would only have the grid with solar acting as a supply (only when the grid is working).

To have any backup you would need bimodal with batteries.

[Mike90250]

Is it possible to connect to the grid using zero injection inverter, in a country that does not have net metering system? just to get the benefit of having the grid as backup

It IS possible. If it's legal in your country, I don't know. You would shave power off the grid for 5 daylight hours.

[Alex_alvar]

I do undersrand the difference between an inverter with battery or inverter connected to the grid.

alright, i do have a follow up question regarding the golf cart station design. Lets say i have a branch panel connected to the grid nearby. Can i connect the inverter which has zero injection to the branch panel and then connect an AC outlet from there to the AC input of the golf cart?

[ButchDeal]

I do undersrand the difference between an inverter with battery or inverter connected to the grid.

alright, i do have a follow up question regarding the golf cart station design. Lets say i have a branch panel connected to the grid nearby. Can i connect the inverter which has zero injection to the branch panel and then connect an AC outlet from there to the AC input of the golf cart?

if it is legal in your country to use zero injection inverters, then yes.

You would be better off with the grid zero capabilities to the main service panel so that it could offset MORE loads than just the golf cart charging though.
BTW, many grid tie inverters have grid zero or zero injection capabilities.

[Alex_alvar]

I agree with you its better to connect to the main panel. But, just for my knowledge i would like to know if it is possible or no?

Alright, if i decided to go with battery charger to golf car config. Do i need any disconnect or fuses before the charge controller or after ?

[Outdoors]

There's a company called genasun That Enables you to charge your golf cart battery from a 100 W 12 V solar panel

[ButchDeal]

There's a company called genasun That Enables you to charge your golf cart battery from a 100 W 12 V solar panel

it really depends on your definition of "Charge"
Technically you could charge a golf cart battery with a 10w module, just going to take time.