Battery Question for Winch

[rolli]

cheers dave....

back on topic. As mentioned, if you are that concerned (which you should be for 'long' use of a winch under load) go the second battery option. And good isolator.

The alternator is never going to keep up with the high demands of winching, and while the load on the winch (which will mean current draw) will vary over any winch for longevity of your battery - a second high cca deep cycle will help you no end.

[Tonto]

Originally Posted by davidd

a deep cycle can be drained and recharged time after time without proble, most will take 300 full discharges and about 1000 half discharges.

That seems to quite the contrary to what I've been reading about deep cycle batteries in general recently ... it's been suggested you shouldn't take them below 50%; that doing so will significantly shorten their life.

I presume you're talking about AGM batteries specifically, not just your typical 'wet' lead acid deep cycle?

[davidd]

tonto you're quite right. if you keep the discharge to 50% you maximise the life of the battery. the few that i have dealt with (not an expert on this ) have stated that the battery should not be flattened below 80 % if possible and will give approx 300 cycles at 80% discharge and will give approx 1000 cycles at 50% discharge. if you get a very large battery and only draw the top few percent it will cycle thousands of times. so yep don't flatten it and it will last longer. if you take say a 115ah battery at $200 and take 80% draw it will cycle in theory 300 times or 66c per cycle and battery is stuffed. cheap fridge power or winch or whatever. but to maximise life keep to 50%. i have a 115ah trojan lead acid to run my fridge and it will in theory run my fridge 3 days. have never drawn down on it more than 2 days, many short draws, just over night. extended holidays, short bbq runs and weekends away. used it to keep shopping cold so i can go off visiting before going home. still going strong, holds charge well and checked water levels a week ago and it is still on max water level. so not flattening it has certainly ben good for ir. should last many years.