I'd run a 10 or 15 amp circuit breaker on hot wire from factory battery to aux so it doesn't kill machine but does recharge after big load is over. I'd love to see the plow in action, I just got a v plow on my pickup and it's impressive to me. Hard to justify in illinois though as we rarely get snow.
If the momentary load exceeds the amp rating of the breaker, it will trip the breaker and stop charging the secondary battery. If the breaker doesn't trip, you still have the exact same problem. The only way to eliminate the problem is to verify that the plow does not have an electrical issue, and then install an ACR (easy)to manage current draw and charging of the second battery, or, reduce the power consumption (not easy) of the accessories. Adding bigger, or more battery capacity may hide the symptom for a little longer, but it will not
solve the problem. It's very easy to install an ACR. Another advantage of the ACR, is that it will keep the primary (starting) battery fully charged. Here's why it's important to keep the primary battery charged: When your starting battery/batteries become partially discharged, all of the electrical devices that are designed to operate on 12v-16v, draw
more than their
rated amount of current (amperage). . As voltage drops, the amps required go up. . Higher amperages cause heat, burning of relays, early failure of starter motors, fuel pump, and winch motors etc., etc.. . The engines computer, ignition system, fuel pump, injectors, are all designed to run within an expected range of voltage- which is why, the engine stalls, or weird shifting, erroneous display info, etc, happens when winches or other high electrical loads are placed on the already struggling charging system, as they momentarily pull voltage below minimum operating threshold. It's important to know how much power all of your accessories are using if you want to keep your machines dependable.. and safe.. . Very important formula: Volts X Amps= Watts. Look up what the charging system output is for your machine, and do the math. . Note that the manufacturer will show Maximum Charging system output at say 3500-5000rpm, you can figure about 25-35% of that at idle. So let's say that the machine is rated at 25 amps of charging output at 13v. 25amps X 13volts = 325watts.
Maximum. Now multiply that number by .25:.. 325w X .25 = *81w at idle.....
! If you convert everything to watts, it's easier to see how much power you actually need. If the winch requires 30amps at 13 volts (390watts) and the battery voltage is actually only 11volts, it still requires 390 watts, so the Amp draw will then increase to 35.5 amps, but in reality, if it's stalling the engine, the voltage is probably dropping below 9 volts. (390w/9v = 43.3Amps)! and poof goes a 40amp fuse, or conversely, the electric motor in the winch will start to overheat, and it's power requirement will go even higher!
So other than the annoyance of stalling engines, erratic shifts etc.,
low voltage dramatically reduces the life of all the electrical components on the machine.
Sorry for going on and on, but this is important stuff to understand if you're adding accessories and want the machine to remain dependable and safe!
