So now that I have a Tacoma ('99 V6 TRD extra cab), I have started building a camping system for the back while I look for a topper. One thing I want is a second battery under the sleeping platform to run lights, an electric blanket etc for the camper without having to worry about running down the main battery. I have read volumes here and elsewhere about dual batteries and battery isolators, and have decided on a fairly simple solenoid/relay based system. I will be installing two identical diehard platinum's, so I am not so worried about charging in parallel. I also like the control of having a three way switch on the dash which can isolate or connect the aux battery or have it switch in with the ignition. I have attached a (super nerdy) schematic of how I am going to wire everything.
One question I have is about fusing for a battery in the bed. I had planned to put a 100 amp fuse in series with my isolation relay. This would protect the cable running under the truck back to the bed. However it occurred to me that I need to fuse it from the other end as well as the rear battery is just as dangerous. The problem with this is that if I want to self jump, I will likely blow the fuses on the main cable. On the engine bay side of things I was thinking of putting a heavy duty battery isolator switch that bypasses the relay and the fuse. I guess I would also need one to bypass the fuse in the bed as well, or do I? Is there such thing as a slow-blow automotive fuse that will allow 10 seconds of cranking current but blow at a constant draw of 100 amps or so?
In a previous life I was an electrical engineer, however for me 3.3V and 100mA was 'high power' so working with a current source than can provide 5000amps is pretty scary.
One question I have is about fusing for a battery in the bed. I had planned to put a 100 amp fuse in series with my isolation relay. This would protect the cable running under the truck back to the bed. However it occurred to me that I need to fuse it from the other end as well as the rear battery is just as dangerous. The problem with this is that if I want to self jump, I will likely blow the fuses on the main cable. On the engine bay side of things I was thinking of putting a heavy duty battery isolator switch that bypasses the relay and the fuse. I guess I would also need one to bypass the fuse in the bed as well, or do I? Is there such thing as a slow-blow automotive fuse that will allow 10 seconds of cranking current but blow at a constant draw of 100 amps or so?
In a previous life I was an electrical engineer, however for me 3.3V and 100mA was 'high power' so working with a current source than can provide 5000amps is pretty scary.
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