Help with batttery system

[Sunking]

I am in the process of replacing my higher usage items with lower wattage replacements. By my current calculations I think I get by with about 110 amps at 12v per day. I

That does not make any sense. Do you mean 110 Amp Hours per day?

Amps is a measure of current flowing at any specific moment. It has no time associated with it. Like watts, it is just measure of rate of power being used at any moment in time, it does not tell you how much energy you are using over a period of time which is Watt Hours.

If you are only using 110 Amp Hours per day at 12 volts, you are likely drawing very small currents. example 4.58 amps x 24 hours = 110 Amp Hours, and at 12 volts is only 55 watts x 24 hours = 1.3 Kwh per day. Well unless you are pulling 110 amps x 1 hour in a day.

[lkruper]

Yes, but if you need 4/0 you should not being using 12 volts. Cable Shops, electricians, Marine Shops, RV Shops, online, and even golf cart shops can make up cables. Even some of the Solar distributors sell them.

I am in the process of replacing my higher usage items with lower wattage replacements. By my current calculations I think I get by with about 110 amps at 12v per day. If I put in solar I would need to cable of about 20 feet from the panels to the battery and another 20 feet from the battery to where the power is being consumed, but if I put a transfer switch in I estimate 10 feet from the battery to the panel.

So I don't think I need 4/0, however even so, if I could buy pre-made cables I think it would be worth it for me. Perhaps I can plan to hire an electrician with solar experience and get the cables made up when I put in the transfer switch.

If I wanted to be 100% on the up and up permit-wise, could I add the batteries, inverter and ground mounted solar panel without another permit and inspection in most places?

[Sunking]

That does not sound like something I really want to tackle myself. Can cable be purchased pre-made at specified lengths so that a novice could connect then without needing to make their own crimps?

Yes, Solar distributors sell them.

[lkruper]

Just to be clear, since only UL Certified recommendations are allowed here. Crimpers were dicussed before as being certified. It is not the crimper, it is the LUG and Crimper combination that create a UL certified crimp. The Lug has a specification as tested by UL or ETL or CSA.

This is a specification :

MagnaLugs are listed by UL/CUL (UL STD 486A), when applied with Quick Cable Quick Crimp tools 4255, 4255R, 4255MR and 4255M.

http://www.quickcable.com/products.php?pageId=79

Yes, I was warned by Sun King and Russ about talking about Chinese crimpers, The problem is they are no better, no worse if you do not follow the combination as prescribed in the specification above as the crimp will fail the UL certification. So posting about a $5,000 battery operated crimper is bogus when it's not listed in the specification of the selected Lug.

A good Battery Cable would also have adhesive lined heat shrink and the AHJ ends up having the ultimate requirements as to Wire type, Welding Cable or MTW since both can have a UL certification, but not for the same use.

That does not sound like something I really want to tackle myself. Can cable be purchased pre-made at specified lengths so that a novice could connect then without needing to make their own crimps?

[Willy T]

Just to be clear, since only UL Certified recommendations are allowed here. Crimpers were dicussed before as being certified. It is not the crimper, it is the LUG and Crimper combination that create a UL certified crimp. The Lug has a specification as tested by UL or ETL or CSA.

This is a specification :

MagnaLugs are listed by UL/CUL (UL STD 486A), when applied with Quick Cable Quick Crimp tools 4255, 4255R, 4255MR and 4255M.

http://www.quickcable.com/products.php?pageId=79

Yes, I was warned by Sun King and Russ about talking about Chinese crimpers, The problem is they are no better, no worse if you do not follow the combination as prescribed in the specification above as the crimp will fail the UL certification. So posting about a $5,000 battery operated crimper is bogus when it's not listed in the specification of the selected Lug.

A good Battery Cable would also have adhesive lined heat shrink and the AHJ ends up having the ultimate requirements as to Wire type, Welding Cable or MTW since both can have a UL certification, but not for the same use.

[Willy T]

For FLA batteries a charging system that cannot deliver at least C/12 (125A for 1500AH) when needed is not likely to keep the battery electrolyte from stratifying, regardless of how little of the battery capacity you use. That requirement can, however, be met using the generator and a separate AC charger rather than the panels alone.
It is correct that the Absorb stage current will not need to be that high as long as the demand is low.

The other thing the Dereck is cautioning about is that if you put a high load on the inverter of a 12V system you will be pulling a lot of current and safely wiring that up on the DC side will be difficult for many people. If you have a welding supply shop nearby, you will find somebody with the tools to put proper terminations on 4/0 cable. If you do not, the cost for tools will be very high. (Do not count on Harbor Fright crimpers!)

Well said 1+

The cables could be a problem for some. Using the cost of 24 batteries ( 2v @ 48 ) vs the cost of custom UL quality cables make them reasonable. The specification of the crimper is designated by the Lug manufacturer and the lug that is used. Some crimpers are reasonable. I have borrowed one back in the day before I bought my own. If you want to use MTW wire then that is what should be used if required. A quick Google search shows a few custom cable makers.

Every system needs be designed for it's intended use and load size, no matter what the voltage is.

[inetdog]

Because you can, if your only pulling it 25-30 % it"s easy. 15% of the daily recharge is non MPPT anyway. 150 amps your talking about is way overkill. Thats why they build generators and 4/0 cable.

For FLA batteries a charging system that cannot deliver at least C/12 (125A for 1500AH) when needed is not likely to keep the battery electrolyte from stratifying, regardless of how little of the battery capacity you use. That requirement can, however, be met using the generator and a separate AC charger rather than the panels alone.
It is correct that the Absorb stage current will not need to be that high as long as the demand is low.

The other thing the Dereck is cautioning about is that if you put a high load on the inverter of a 12V system you will be pulling a lot of current and safely wiring that up on the DC side will be difficult for many people. If you have a welding supply shop nearby, you will find somebody with the tools to put proper terminations on 4/0 cable. If you do not, the cost for tools will be very high. (Do not count on Harbor Fright crimpers!)

[Willy T]

Well I agree with Sunking that if your needs are less than 1kWh per day you can build a system using a 12volt battery.

What I was saying is why would someone build a 12volt 1500Ah battery system? That makes no sense because you need 150amps of CC, extremely large wires and fusing. There are also more losses when using a lower voltage than a higher.

Because you can, if your only pulling it 25-30 % it"s easy. 15% of the daily recharge is non MPPT anyway. 150 amps your talking about is way overkill. Thats why they build generators and 4/0 cable.

[SunEagle]

That was the question for Sun King, he came up with the 1 KWH a day , was all a 12 v system was capable of, guess he pulled out of his hat or somewhere else.

Well I agree with Sunking that if your needs are less than 1kWh per day you can build a system using a 12volt battery.

What I was saying is why would someone build a 12volt 1500Ah battery system (6 x 2volt 1500Ah that you mentioned)? That makes no sense because you need 150amps of CC, extremely large wires and fusing. There are also more losses when using a lower voltage than a higher.

[Willy T]

Why would anyone purchase a 1500Ah 12volt battery system to just run 1kWh a day? You would also need a solar array that will produce (after loses) 150Amp to keep that 1500Ah battery happy.

Talk about over kill to cover 1 kWh per day or about $0.12 for me.

That was the question for Sun King, he came up with the 1 KWH a day , was all a 12 v system was capable of, guess he pulled out of his hat or somewhere else.

RV and small boats where less than 1 Kwh per day is required.

[SunEagle]

.....
Where does the 1 KWH a day come from ?? I am guessing you'v never seen a 1,500 amp hr bank of 2 v, l16 batteries on a 12 v system ??

Why would anyone purchase a 1500Ah 12volt battery system to just run 1kWh a day? You would also need a solar array that will produce (after loses) 150Amp to keep that 1500Ah battery happy.

Talk about over kill to cover 1 kWh per day or about $0.12 for me.

[Sunking]

But wait, you did mention the batteries are golf cart batteries? If I remember right the golf cart batteries are hybrid and can take higher charge and discharge rate? Well Dereck can you please confirm this?

Correct Golf Cart Batteries are hybrid and can easily handle 40 amps or C/5 charge currents.

Another thought if used as a an Emergency Stand By systems use what industry uses, Rectifiers. They are Float Chargers and there are thousands of them available salvage operators that buy from Telephone and CATV industry. In 24 volts anywhere from 10 to 1000 amps. They are designed to last 50 years and tough as heck. They have 3 setings.

Float Voltage
EQ Voltage
Current Limit.

Made to work with any battery type. Ebay, ham radio sites, and dozens of salvage operators can be easily found.

[Sunking]

He continually hurls insults about people that have a 12 volt system

Tough talk for someone who calls themselves a professional and does not even have a basic fundamental knowledge of the subject. Especially ironic you have been warned by the mods for suggesting UNSAFE and UNETHICAL practices. That is not a Pro. You got what you asked for.

I take time to explain detailed theories, principles and why's with a priority on safety and professionalism. I even go the extra mile and make detailed drawings and get thanked daily for my time and help. I have saved may folks thousands of dollars by preventing them from making the 12 volt mistake. 12 volts has it place low power very small systems like those used in RV and small boats where less than 1 Kwh per day is required. Otherwise they are too dangerous and expensive. If you really knew the physics, understood the principles. and a professional you would know that. Fact is you do not know it and call yourself a pro.

[paulcheung]

I (OP) haven't vanished, I'm just keeping my head down till the pissing contest has settled down.

I haven't been able to find anything resembling a "60 amp float charger". So the Iota DLS and Iota IQ4 3-Stage Battery Charger Module seem to be what would work just fine. My question is 25 amp or 40 amp? I do plan to get some panels some day, allot of folks on the island I live on have PV solar systems. I appreciate the help from both you guys.

If you use 225 AH FLA battery in series. the 25 amps model for you, the 40 amps model is for 320 to 480 Ah batteries unless you use AGM or other battery chemistry.

But wait, you did mention the batteries are golf cart batteries? If I remember right the golf cart batteries are hybrid and can take higher charge and discharge rate? Well Dereck can you please confirm this?

[stevo]

I (OP) haven't vanished, I'm just keeping my head down till the pissing contest has settled down.

I haven't been able to find anything resembling a "60 amp float charger". So the Iota DLS and Iota IQ4 3-Stage Battery Charger Module seem to be what would work just fine. My question is 25 amp or 40 amp? I do plan to get some panels some day, allot of folks on the island I live on have PV solar systems. I appreciate the help from both you guys.