HueyPilotVN
Well-known member
Mobile Auxiliary Battery Bank
This post is long, I think it is interesting but it is long.
This is a new project but I have been working on it on and off for a while. I even asked Lou about it a couple of years ago.
I carry around 16 batteries, but six of them are in a Golf Cart. I also have about 1500 watts of solar panels between the coach and the Stacker. I am sure that much of the time the charging electricity from the solar panels is not going anywhere because the batteries are full.
So I came up with a very easy method of increasing the size of the battery bank by double or even triple the capacity using the golf cart batteries.
The challenge in using the 660 amp hours of capacity has been that the golf cart is wired in series to provide 36 volts and what I need to attach the batteries to either of my RV battery banks is 12 volts.
Now if I had all the time in the world while boondocking I guess that I could rewire the batteries in an hour or so. I wanted a very quick and easy way to switch from 36 to 12 volts and back in seconds, not hours.
The solution involved using the quick disconnect switches that many of us use to manually disconnect a battery in storage. These switches have a plastic key. When you insert the key and turn it right the connection is made and the switch is closed. If the key is removed the switch is open and no current flows thru it.
This was a perfect method for allowing me to safely reconfigure the wiring with only six switches. Starting by making sure that no keys are inserted all six switches the golf cart are open, battery banks configuration is three 12 volt batteries that are not connected in parallel. If you put in only the two red keys and close only the two red switches the factory wiring is restored and you have 36 volts of power to use the golf cart as a golf cart.
If you put in only the four green keys and close only the four green switches then you have the functional equivalent of a very large series/parallel 12 volt battery with 660 amp hours of storage capacity.
Never put all six keys in and turn them. Either two red for 36 volts or four green for 12 volts. Using the configuration this way is perfectly safe. However turning all switches on will cause shorts. If you do this then you need to understand how this works.
By using the heavy duty connecting cables rated for 175 amps as shown in the pictures to hook up in parallel you can convert a typical battery bank of 4 T-105s with a capacity of 440 amp hours into a 1.1K amp hour bank that has a 250% higher capacity.
I now have these 4 battery configurations in both the coach and the stacker. By having the connector plugs, (similar to a heavy duty version of the typical winch plug) I can choose to more than double either of the battery banks.
I can also benefit by using the 1500 watts of solar to also charge my golf cart even if I do not need it for increasing the RV bank capacity by just switching it to 12 volt mode.
Here are some pictures.
This post is long, I think it is interesting but it is long.
This is a new project but I have been working on it on and off for a while. I even asked Lou about it a couple of years ago.
I carry around 16 batteries, but six of them are in a Golf Cart. I also have about 1500 watts of solar panels between the coach and the Stacker. I am sure that much of the time the charging electricity from the solar panels is not going anywhere because the batteries are full.
So I came up with a very easy method of increasing the size of the battery bank by double or even triple the capacity using the golf cart batteries.
The challenge in using the 660 amp hours of capacity has been that the golf cart is wired in series to provide 36 volts and what I need to attach the batteries to either of my RV battery banks is 12 volts.
Now if I had all the time in the world while boondocking I guess that I could rewire the batteries in an hour or so. I wanted a very quick and easy way to switch from 36 to 12 volts and back in seconds, not hours.
The solution involved using the quick disconnect switches that many of us use to manually disconnect a battery in storage. These switches have a plastic key. When you insert the key and turn it right the connection is made and the switch is closed. If the key is removed the switch is open and no current flows thru it.
This was a perfect method for allowing me to safely reconfigure the wiring with only six switches. Starting by making sure that no keys are inserted all six switches the golf cart are open, battery banks configuration is three 12 volt batteries that are not connected in parallel. If you put in only the two red keys and close only the two red switches the factory wiring is restored and you have 36 volts of power to use the golf cart as a golf cart.
If you put in only the four green keys and close only the four green switches then you have the functional equivalent of a very large series/parallel 12 volt battery with 660 amp hours of storage capacity.
Never put all six keys in and turn them. Either two red for 36 volts or four green for 12 volts. Using the configuration this way is perfectly safe. However turning all switches on will cause shorts. If you do this then you need to understand how this works.
By using the heavy duty connecting cables rated for 175 amps as shown in the pictures to hook up in parallel you can convert a typical battery bank of 4 T-105s with a capacity of 440 amp hours into a 1.1K amp hour bank that has a 250% higher capacity.
I now have these 4 battery configurations in both the coach and the stacker. By having the connector plugs, (similar to a heavy duty version of the typical winch plug) I can choose to more than double either of the battery banks.
I can also benefit by using the 1500 watts of solar to also charge my golf cart even if I do not need it for increasing the RV bank capacity by just switching it to 12 volt mode.
Here are some pictures.
Attachments
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r original wiring.jpg226.5 KB · Views: 50
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r factory wiring.jpg115.9 KB · Views: 42
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r final wiring solution chart.jpg112.6 KB · Views: 32
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r chart easier to understand.jpg99.7 KB · Views: 22
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r final wiring solution.jpg202.6 KB · Views: 38
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r battery switch.jpg171.7 KB · Views: 31
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r switches close up.jpg212.7 KB · Views: 34
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r switch keys.jpg114.6 KB · Views: 25
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r connectors 175 amp.jpg244.5 KB · Views: 29
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r solution without moving batts.jpg127.4 KB · Views: 24
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r 175 amp connectors.jpg164.6 KB · Views: 33