New to forum. 150 Golf Cart Batteries solar setup midwest

[keeko785]

So here is the scenario

I am in the midwest near the canadian border. I don't plan to ever use XCEL energy again. I already disconnected the main leads coming in from the power company(into my panel)

The building is a commercial building that I basically use for storage and hobby use ect. About 3500 sq ft building.

I have a boat load of 12 volt LED lights and a boat load of 120volt LED lights.

Heating is by means of firewood.

I have about 150 golf cart batteries that are 6 volt (deep cycle) Brands include trojan, energizer and interstate. I have been playing around with a 1.5 watt solar panel, 3 watt solar panel and a 7 watt solar panel.

I have 4 inverters, 300watt, 800 watt, 800watt and 800 watt.


I have been wiring these in series so I have 12 volts coming from each set of batteries, I then have been hooking up my batteries to an inverter when I decide to do some work in the shop, to power lights, radio ect...

Now I understand light output in my area during the winter is poor, but the 7 watt solar panel charges the batteries very well.

My questions are as follows
1 how should I be charging them? Should I charge each 6 volt battery individually till it reaches correct voltage, or should I keep them wired in series and charge them till they reach 12 volts(or slightly higher).

Or should I bite the bullet and buy a xantrax 36 or 48 volt charger/inverter and hook that directly to my electrical panel on the wall giving all outlets in the building 120volts...

I really don't want to spend thousands of dollars to accomplish this as its only a hobby shop and I am just avoiding paying xcel for monthly service especially in the months when I hardly use the shop.

I don't run fridges, washers, dryers or even a water heater. Highest output appliance is a radio or 18volt cordless drill charger.(maybe a sawzall) so 1500 watts on 1 circuit is at most. The lighting is again all LED so it draws nearly nothing.

I have all the existing wiring from the golf carts so I can wire them all together to achieve the 36 volts or 48 very easily.

I understand the basics of solar, knowing a charge controller, and temp sensor is important. This is in a shop setting that nothing can catch fire, but I would like to be safe and have this done right without spending $1500 on a inverter.

I have wind power available to me during the summer months but the winter months is slightly different. So far I have powered everything in my shop area for 60 days with only 18 batteries(never recharging them)(this is because i only had a 1.5 watt charger and it wasn't able to put any type of charge on the batteries. Now that I Have purchased a 7 watt solar panel it charges a 6 volt battery in no time.

What are my options to make sure I am not causing harm or shortening the life of the batteries.(I understand I don't want to undercharge or overcharge them)

[Sunking]

Time to break out the popcorn.

[Mike90250]

Time to break out the popcorn.

We need a map, to watch the fire trucks.

Welcome keeko785. Do you want your back rubbed, or do you want an honest evaluation of what you have built ?

[keeko785]

We need a map, to watch the fire trucks.

Welcome keeko785. Do you want your back rubbed, or do you want an honest evaluation of what you have built ?

So I think you guys must be confused

I got the 150 golf cart batteries for free. There for I would like to utilize them. I understand if I had $15,000 to spend on batteries 6 volt golf cart batteries might not be the best idea.

However here we are, 150 free batteries. No public use of solar system and workspace) (I don't have to worry about an inspector but I would like safe to use disconnects and I have a very expensive system that is used to fill the batteries with filtered water(made for golf cart batteries)).


I have not wired them in 36 volt or 48 volt banks because I haven't purchased any circuit breakers yet. I had an electrician help me out thus far but he said he has no idea on the solar side so he requested I resort to the internet.

[russ]

So I think you guys must be confused

Nope - You are the confused one - your electrician is trying to tell you no way I suppose.

You have no idea how nice of a bomb you are working on.

[keeko785]

Nope - You are the confused one - your electrician is trying to tell you no way I suppose.

You have no idea how nice of a bomb you are working on.

In my first post I put "So far I have powered everything in my shop area for 60 days with only 18 batteries"


So this tells me with minimal solar panels I only need to utilize 10-20 batteries to accomplish my goal. I am not simply stacking 150 batteries and hooking them together. I plan to put the other batteries on the opposite side of the building with a trickle charger so they will stay charged, desulfate and maintain properly.

Can anyone post something constructive so I can achieve my goal?

Again I am using an electrician for all the 120 volt parts of the plan but he said he can do the math if I provide him with the proper materials but he has no idea where the real world result will be because he guarantees the math will not be perfect given the variables.

[Sunny Solar]

I have been playing around with a 1.5 watt solar panel, 3 watt solar panel and a 7 watt solar panel. There is some possibility you may undercharge them with any of those panels.
On second thoughts im sure you will..

150batts 6v into 3 strings would give you a nice 300vdc. Now you just need to buy an industrial inverter to convert that to 230vac. And while your shopping look for a solar charger that can handle 300v.

Now I suggest you may need upgrade the 3 solar panels you have to something larger..Something like this..1000x200w panels.As you need about 750a at about 10% to charge the batteries..

Now you may find those three items are going to be a bit expensive??

Alternative....Sell 140 of the batteries "as is where is" This will give you some coin to buy a 24v solar charger and a 24 v 1500w inverter.

[keeko785]

Sunny, I have been playing around with a 1.5 3 and 7 watt because those are ones I use to maintain my lawn equipment that sits outside during the summer.

I like to play around with things that cost 10-30 so that I can learn more about how they work and I love working with a multimeter.

So now that I have the basics figured out I would like to move forward with figuring out how to safely charge, and use 10-20 batteries(However I would like keep the 130-140 batteries maintained with a 120 volt trickle charger.

Since we are going 24 volt why wouldn't you just wire the batteries so they are 24 volt battery banks and buy a 24 volt 600watt wind generator and a good inverter/charge controller(24 volt of course)

Again I have wind at my disposal. Since I am not discharging the batteries hardly at all(being its a hobby shop for myself) I don't think I need 1,000 solar panels?

[Mike90250]

OK, so here's the deal.

150 free batteries, are just simply un-manageable. Way too many interconnect wires to buy, and maintain. Same with pulling battery caps and adding water on a monthly basis - thats 150 x 3 = 450 caps to check.

More than 2 batteries or strings in parallel, becomes problematic to keep charge and discharge balanced.
see : http://www.smartgauge.co.uk/batt_con.html

Charging - the troubles of large batteries and small PV charging, was tried in solar's young years, and it was found that the massive parallel bank, eventually could not be charged, and the cells had sulfated.

And your 20 watts of solar is, essentially, nothing for recharging batteries. 5 watts is a trickle charge for a car battery, that's the size of panel VW plugs on the dashboard for overseas shipping of new cars. So you would need 750 watts just to maintain a trickle charge in 150 batteries.

But if you are sure this is going to work, keep us posted in 6 months, that's about how long the factory charge will last and keep the LED's going before the cells die completely.

There is just no useful way to even buy the clamps, fuses and cables to interconnect all these.

[Naptown]

Your best shot at this is to start right off with a 48V system. This will allow you to use 8 or 16 of your batteries for the electric in the shop.
I say 8 or 16 in that more than 2 strings of parallel batteries are almost impossible to balance and charge / discharge equally and they will die a rapid death.

You need in the worst way to calculate energy use in the shop (use a Kill a watt meter)

thee is an off grid calculator in my sig line. use that to determine the amount of solar you will need based on usage.
For the primary bank you will need at a minimum 200 watts of solar to maintain them.

The problem is going to be maintaining the other 100+ batteries.
You are correct in putting them on a float charger when completely charged up. However you say this is to be 120V. Since the grid has been disconnected where will this 120V come from? you will need to calculate multiple chargers (50+) and what they will use in the equation.

[keeko785]

OK, so here's the deal.

150 free batteries, are just simply un-manageable. Way too many interconnect wires to buy, and maintain. Same with pulling battery caps and adding water on a monthly basis - thats 150 x 3 = 450 caps to check.

More than 2 batteries or strings in parallel, becomes problematic to keep charge and discharge balanced.
see : http://www.smartgauge.co.uk/batt_con.html

Charging - the troubles of large batteries and small PV charging, was tried in solar's young years, and it was found that the massive parallel bank, eventually could not be charged, and the cells had sulfated.

And your 20 watts of solar is, essentially, nothing for recharging batteries. 5 watts is a trickle charge for a car battery, that's the size of panel VW plugs on the dashboard for overseas shipping of new cars. So you would need 750 watts just to maintain a trickle charge in 150 batteries.

But if you are sure this is going to work, keep us posted in 6 months, that's about how long the factory charge will last and keep the LED's going before the cells die completely.

There is just no useful way to even buy the clamps, fuses and cables to interconnect all these.

Now were getting somewhere.

Ok for the sake of argument the other 140 batteries do not need to be checked every single month(filled ect..) They are simply in a constant temp environment and are not being put under a load, so yes your right to a degree but Im sure I can just check them every 2-3 months for level and fill if necessary.

I have a few hundred cables all of which are the exact same length, so my intitial idea was to put all of these batteries in 36 volt banks on pallets.

So that would put 6 batteries on each pallet, wired together, that leaves 25 pallets in my shop area. Each pallet has a 36 volt battery charger/charge controller(golf cart battery charger)
When the wind blows I can simply hook up my xantrax inverter to the wind generator, hook up that inverter into my 36 volt battery charger and recharge the batteries.

So to summarize I have 25 pallets, 150 batteries, 25 36 volt battery chargers and hundreds of 3/4 inch nuts and hundreds of equal length wires(with eyelets) to connect the batteries together.

I haven't purchased the solar panels that I plan to use yet(i will use this forums help to point me in the right direction)

One of the posters suggested selling the batteries, these batteries are worth $15,000 retail, if I sell them off to people I will probably net $5000-7000. To loose $8,000 to $5000 in the first week of this project sounds like a horrible idea(granted I didn't pay $15,000 for them but that is technically their value). Keep posting guys were going in the right direction.

[keeko785]

OK, so here's the deal.

150 free batteries, are just simply un-manageable. Way too many interconnect wires to buy, and maintain. Same with pulling battery caps and adding water on a monthly basis - thats 150 x 3 = 450 caps to check.

More than 2 batteries or strings in parallel, becomes problematic to keep charge and discharge balanced.
see : http://www.smartgauge.co.uk/batt_con.html

Charging - the troubles of large batteries and small PV charging, was tried in solar's young years, and it was found that the massive parallel bank, eventually could not be charged, and the cells had sulfated.

And your 20 watts of solar is, essentially, nothing for recharging batteries. 5 watts is a trickle charge for a car battery, that's the size of panel VW plugs on the dashboard for overseas shipping of new cars. So you would need 750 watts just to maintain a trickle charge in 150 batteries.

But if you are sure this is going to work, keep us posted in 6 months, that's about how long the factory charge will last and keep the LED's going before the cells die completely.

There is just no useful way to even buy the clamps, fuses and cables to interconnect all these.

Mike, thanks for your input, But I already have the cables, nuts so that cost will not be involved in this scenario.

ALSO I should state, that I have 3 inverters already(these I do not plan to use on the setup, they are simply inverters I already own, they are for vehicles but I have been using them to light up my tools and lights while im organizing this bomb.

[russ]

Now were getting somewhere.

One of the posters suggested selling the batteries, these batteries are worth $15,000 retail, if I sell them off to people I will probably net $5000-7000. To loose $8,000 to $5000 in the first week of this project sounds like a horrible idea(granted I didn't pay $15,000 for them but that is technically their value).

Those are presidential economics! You can't bank value until a transaction takes place.

[Mike90250]

.... Ok for the sake of argument the other 140 batteries do not need to be checked every single month(filled ect..) ....

Ah, but you do need to maintain them, Monthly, they need a top off charge. The loose 10% charge a month, and if you don't top them off, they will sulfate and die.
When in service, being charged and discharged, the consume water, and you need to check it.

[FloridaSun]

Those are presidential economics! You can't bank value until a transaction takes place.

..and the longer he holds on to those batteries the less they are worth. Better to dump them now instead of selling for scrap value in a year or two. Storing 150 batteries sounds more like a liability than an asset. 'Free' sound like used/useless to me. I'd take them tho at $5-$10@ scrap value.