Winch and Battery on antique ATV/UTV

[John_Mc]

A question on how the Battery Isolators work:

I assume you guys have your original ATV starting battery hooked up as the main battery, and the larger battery as the auxiliary. I would assume the winch is connected directly to the auxiliary battery.

I'm trying to picture how the isolator operates, particularly when the aux. battery has been partly discharged from using the winch. If I read the isolator description correctly, the aux battery will not be charged unless the main battery has already been topped off. Once that happens, the aux battery is connected. It would seem there would be a heavy draw, both from the alternator and the main battery, sucking down the main battery in the process. Eventually, the aux battery would be disconnected until the main was brought back up to full charge, at which point, the aux would be connected again. If the aux were deeply discharged, this could cause a fair amount of cycling on and off. Has that cycling ever been a problem? Is the heavy current flow from having two unequally charged batteries connected to each other (when the Aux battery is brought into the circuit) likely to be a problem?

 

[jaxs]

Those are all legitimate concurns John but I can't precisly answer them. Until you research it for yourself,I suggest keeping the large winch battery seperate from starting battery. If you plan heavy enough use of winch to require the limited power starting battery offer's,install 2 heavy duty batteries. If you insist on stand alone system where all batteries are recharged from atv,it might be wise to drive an automobile alternator off the engine. Setting it up isn't much more trouble and expense than installing all the necessary provisions to protect atv alternator. The age and brand of machine isn't relavent, research the modern Briggs encine. Research what engine mfgr say's about using large batteries on their engine. Alternatly,see what Honda/Kawasaki say's about their machines. From personal experience,this is what I can tell you. I make every attempt to avoid batteries sitting very long in a state of discharge. I attempt to use smart chargers to replenish batteries with less than 80% charge in them. I NEVER alow strangers to hook booster cables up. If I run winch or dump battery down,I either take time to high idle (alternator charging at less than total capacity) before hitting the road or simply disconnect battery from truck. I have always owned several vehicles (tractors,trucks,automobiles,atv,utv,boat,lawn tractor,dump trailers,rv and motorcycle) at the same time for 50 years. My batteries have always lasted twice as long as the average person's and I rarely have alternators go bad. Here's something you can witness for yourself. Intentionally install a discharged battery on a cold engine then boost it off and bring engine up to 1500-2k rpm. Lay your hand on alternator as it recharge's battery. You will soon understand why alternators are not intended to recharge dead batteries,more so just maintain them. If you tear down a pile of bad alternators,you will find 75% failed because solder holding diodes melted.

 

[John_Mc]

Jaxs - I agree wholeheartedly about keeping batteries charged. I first learned this when maintaining the battery on my aircraft: those suckers cost about $500 a pop, and average life for one in a small piston aircraft is about 5 years IF it is used fairly regularly (they live a tough life: high vibration, temperatures extremes, some go for extended periods without use). I doubled the life of mine by keeping it on a 24V aviation-specific smart charger (BatteryMinder brand). I was so please with the results, that I now own a total of 4 smart charger/maintainers - each with a desulfation circuit. I don't even let my batteries sit at 80% charge level for any length of time if there is any way to avoid it, since spending extended times even in partial discharge can contribute to sulfation.

Unfortunately, I don't have room for two heavy duty batteries. In fact, the one I'm adding will only be installed when I'm likely to need it. The old Coot only has room in the frint tub for a garden-tractor sized battery. I like to keep the rear tub clear for cargo, but that's where the deep cycle battery will go when it's installed. I do have a pull start on the engine as a back up, in case I mess things up.

All this reminds me: I've still got to finish rewiring the Coot and hook the ammeter back up.