Solar battery charger with a remote battery kill switch

[Rifleman]

Okay my question is this, i have installed one of the solar chargers that another member here on S.S. has been selling. What i want to do is install a remote keyed battery disconnect switch to protect my truck from being stolen. Now after i have installed this new battery disconnect switch on the ground cable side of the circuit will my solar charger still keep my battery's charged. Seeing as the ground circuit will now be disconnected when i have the switch turned off because of the new battery disconnect switch?

 

[tbone1004]

it all depends on how you have wired everything.
First question is why are you cutting off the ground? Typically kill switches are wired on the positive side between the positive terminal of the battery and the ignition coil. If you switch the ground side all you have to do is take a jumper cable and ground it that way, positive side is much more difficult.

That is your typical ultra basic wiring diagram with a kill switch. Your battery charger and alternator should be on the same circuit and said circuit should bypass the kill switch going straight to the battery. Kill switch really is just to cut power to the ignition coil. You're running a 5ton, so diesel. In that case, just take that wiring and replace ignition coil with fuel pump. That way you have no power to the fuel pump, and no power to the starter, ergo no start. Not too terribly difficult to bypass, but everything is bypassable if you're motivated enough. You really only need to cut off power to the starter, but most of the solenoids will have a low amp circuit as well as a high amp circuit so you can put the fuel pump on there for added security. Either way, just wire the alternator and solar charger straight to the battery and all will be well

 

[Rifleman]

The reason for putting it on the ground cable is if you disconnect the ground cable that "kills" everything in the truck, no ground, no complete circuit. Also if you should happen to "short" that switch or cables while connecting it using the ground cable you will get no arc or short. Another reason for using the ground, that's what other members here who have installed kill switches recommended and it's also what the switch make recommended when i talked to them too. Now if you have a better idea i am willing to listen.

 

[tbone1004]

If you want to disconnect the negative side of the battery the switch will function properly and that is how some in the race industry do it when they need to kill the engines mid-race, but connecting the hot-side will act as a perfectly good theft deterrent and that is how just about every other keyed automobile works. Plus, if you run it on the ground side you have to use one big ass switch for those grounding cables vs. running itty bitty 10ga or whatever size your harness has for the fuel pump and the starter solenoid.

My M37 has a keyed ignition switch which controls power to the coil and the master battery disconnect is on the hot side of the battery. This disconnects any potential draws from the batteries when the truck is off. The marine industry and automotive industries use switches on the positive side of the battery to disconnect the ignition and fuel systems as well as to truly isolate the batteries, so I see no reason to try to reinvent the wheel.

Now, think about how you're going to connect that solar charger if you have a ground disconnect. You're going to have to wire it to both terminals on the battery to complete that circuit. Now, if that charger is connected and running while someone tries to steal it, they could, in theory have the proper closed circuit they need and you would see arcing on the ground side when that starter turns. It is unlikely, but depending on how you mount that charge panel, the negative side of the panel could ground itself through the mounts creating a frame mount to the battery terminal. This would have insanely high resistance, but it theoretically could work. If you disconnect the positive side there is no risk for this since everything is still grounded, but power is only flowing on the charger side and the rest of the power is cut to the truck. If the switch fails, you obviously have a problem, but if the switch fails on the ground side you still have a problem.

Not trying to be argumentative, but as an engineer you have to think of all potential problems and tailor the solution to your needs, which center around security against unauthorized ignition while still allowing the charging systems to function properly.

 

[JOateyNV]

The easy / short answer to the question is YES. The solar charger will work. It is wired straight to the batteries. If you have any questions about how the Pulsetech Kit should be wired feel free the PM me.