maxingout
Adventurer
Every time I prepare a Defender for expeditionary travel, I always have to decide how I am going to create my dual battery installation. I look at the expensive fancy systems designed for dual batteries, and I ask myself whether this time around I am going to go fancy or go basic.
I see the benefits and convenience of the fancy systems, and I am tempted to move into the twenty-first century and install the electronics associated with a modern dual charging system.
I have had six Defenders, and in each truck I opted for a basic system without any electronics. I keep my expeditionary vehicles as simple as possible, and I avoid electronics whenever I can get away with it.
My dual battery system is the essence of simplicty. I place a high amperage switch between the two positive poles of the batteries, and that switch regulates whether one or both batteries are charging or discharging. When the switch is in the on position, both batteries are charging or discharging. When the switch is in the off position, only the "house" battery is discharging, and the engine starting battery is isolated from the current draw associated with the accessories that I run on my truck.
I run battery cables from the positive poles of each battery to a switch that can handle 500 amps of current. The switch has only two positions. It is either on or off, which means the batteries are either connected or disconnected through the switch.
The battery box in a Land Rover has enough room that the batteries can move around slightly even when clamped in position with the tie down clamp. To stop the batteries from small movements, I place 3/4 inch plywood inserts next to the battery so that the battery has no place to move when travelling on uneven terrain or with sudden stops. I mount the dual charging switch on the plywood so that the switch is securely fixed in place, and there is no chance of the switch shorting out against the metal of the battery box. I place a couple of globs of silicone under the plywood inserts so they are glued securely in place.
This system is not very convenient, but it is secure. It has never failed me in my six Defenders. When I want to change the position of the switch, I open the battery box and flip the switch. In practical terms that means I turn the switch on connecting both batteries in the morning, and before I go to sleep at night, I move the switch to the off position where the batteries are disconnected from each other. Although most people would not want to enter their battery box twice a day, when I am on an expedition, I don't mind the extra work. I want to look at the batteries twice a day to make sure everything is in order. I also want to discipline myself to be sure that I have disconnected the batteries from each other at night. That way I know I will have power to start the car in the morning.
When we did expeditionary travel in the Arabia Desert, we checked our batteries, our oil, our coolant and radiator cap as part of our routine daily vehicle checks before we headed off for another day of desert exploration. Those checks kept us honest and out of trouble. Flipping a battery switch twice a day was a routine part of our daily checks, and it did not seem onerous. It's simply what you should do if you are doing deep desert exploration.
If my Defender was only used for touring in the USA, I might consider the fancy electronic system, because if it breaks down, help usually is not too far away. But for deep desert trips in remote locations outside the USA, I don't want to have to deal with electronics that might fail at an inconvenient time, and I don't want to face any diagnostic dilemmas with the electronics of a dual charging system. I have only one switch to consider, and if it fails, then I will simply join the positive poles of the two batteries with a single cable.
None of this is rocket science. It is keeping things simple on an expeditionary vehicle. I know that when I am in Bongo Congo, I won't have to worry about my dual battery system.
I see the benefits and convenience of the fancy systems, and I am tempted to move into the twenty-first century and install the electronics associated with a modern dual charging system.
I have had six Defenders, and in each truck I opted for a basic system without any electronics. I keep my expeditionary vehicles as simple as possible, and I avoid electronics whenever I can get away with it.
My dual battery system is the essence of simplicty. I place a high amperage switch between the two positive poles of the batteries, and that switch regulates whether one or both batteries are charging or discharging. When the switch is in the on position, both batteries are charging or discharging. When the switch is in the off position, only the "house" battery is discharging, and the engine starting battery is isolated from the current draw associated with the accessories that I run on my truck.
I run battery cables from the positive poles of each battery to a switch that can handle 500 amps of current. The switch has only two positions. It is either on or off, which means the batteries are either connected or disconnected through the switch.
The battery box in a Land Rover has enough room that the batteries can move around slightly even when clamped in position with the tie down clamp. To stop the batteries from small movements, I place 3/4 inch plywood inserts next to the battery so that the battery has no place to move when travelling on uneven terrain or with sudden stops. I mount the dual charging switch on the plywood so that the switch is securely fixed in place, and there is no chance of the switch shorting out against the metal of the battery box. I place a couple of globs of silicone under the plywood inserts so they are glued securely in place.
This system is not very convenient, but it is secure. It has never failed me in my six Defenders. When I want to change the position of the switch, I open the battery box and flip the switch. In practical terms that means I turn the switch on connecting both batteries in the morning, and before I go to sleep at night, I move the switch to the off position where the batteries are disconnected from each other. Although most people would not want to enter their battery box twice a day, when I am on an expedition, I don't mind the extra work. I want to look at the batteries twice a day to make sure everything is in order. I also want to discipline myself to be sure that I have disconnected the batteries from each other at night. That way I know I will have power to start the car in the morning.
When we did expeditionary travel in the Arabia Desert, we checked our batteries, our oil, our coolant and radiator cap as part of our routine daily vehicle checks before we headed off for another day of desert exploration. Those checks kept us honest and out of trouble. Flipping a battery switch twice a day was a routine part of our daily checks, and it did not seem onerous. It's simply what you should do if you are doing deep desert exploration.
If my Defender was only used for touring in the USA, I might consider the fancy electronic system, because if it breaks down, help usually is not too far away. But for deep desert trips in remote locations outside the USA, I don't want to have to deal with electronics that might fail at an inconvenient time, and I don't want to face any diagnostic dilemmas with the electronics of a dual charging system. I have only one switch to consider, and if it fails, then I will simply join the positive poles of the two batteries with a single cable.
None of this is rocket science. It is keeping things simple on an expeditionary vehicle. I know that when I am in Bongo Congo, I won't have to worry about my dual battery system.
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I appreciate the education!
