Master Power Control
The bum finger is still slowing me down. The rain too. So, more little projects indoors. The rust will have to wait.
I wanted to make a few changes to my two-battery charging setup. Part 1 was to get rid of the dual-diode setup. It worked fine, but I figured I’d switch to a beefy relay-based system so I can charge just a little bit more efficiently and eliminate the ~1V diode drop. I also wanted to put in a low voltage cutoff on the radio, fridge, and inverter lines. We ran down the 2nd battery more than a few times and it’s just not good. Then, tie in the solar charge controller like before. And, a new aux charger that will automatically top-up the 2nd battery and run all the above stuff any time we are plugged in. This is just a 150W voltage-selectable power supply. I could have gone bigger, but it was only 5 bucks on ebay. I may need to put a heat sink on the lone diode, but I’ll wait and see.
Hi Jason,
What’s the lone diode doing? Are the relays to switch accessory loads from aux battery to the main when the engine is running? Just trying to wrap my brain around the design in case I ever go beyond yelling at the kids and carrying jumper cables as my camping battery solution.
Chris – I’m currently nursing yet another Red Beard-inflicted injury, but will post a circuit diagram when I can. The lone diode is between the universal power supply and the aux battery. It’s probably not necessary, except that my supply is 15V, so this drops it to 14V – just the right value for charging without some other power regulator.