While sailing this weekend using gps,autopilot, refrigeration - these items drained a fully charged battery after about 4 hrs. Is that normal? Is it the autopilot that is a big drain?
autopilot battery drain
- Thread starter jonfreiden
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Yes, the AP can be a major factor. It is one of those things that should be in your electrical usage spreadsheet. Do you have a way to measure the amps? I have watched the AP while sailing on my Link 2000. It is hard to average while watching. But you will get some idea. Of course the fridge ranks up there too.
When I installed my Simrad wheelpilot I intentionally set the bias so that it doesn't constantly "hunt". It goes off a course a couple of degrees and then brings it back. Not real efficient for getting from A to B maybe but much easier on the batteries.
When I installed my Simrad wheelpilot I intentionally set the bias so that it doesn't constantly "hunt". It goes off a course a couple of degrees and then brings it back. Not real efficient for getting from A to B maybe but much easier on the batteries.
Like all things electrical (except reefers)
it depends.
If the waves are not too contray then an autopilot does not draw much current. If you see it making a lot of steering imputs the the AH do go up a good bit.
A reefer can really suck the life out of a battery banks though if you don't have good insulation or your freon charge is low or it is just hot outside. GPS and instriments don't draw much at all. (less than an amp with all turned on)
I have a 400 AH bank and the reefer draws 7 amps at almost 100% duty cycle in the heat of summer. that is 7*24=168 AH a day or just a little over a day before I get to 50% on the bank. even less after a few days of crusing as I don't leave the motor running to get a full charge. Course in the fall and spring it hardly comes on at all.
it depends.
If the waves are not too contray then an autopilot does not draw much current. If you see it making a lot of steering imputs the the AH do go up a good bit.
A reefer can really suck the life out of a battery banks though if you don't have good insulation or your freon charge is low or it is just hot outside. GPS and instriments don't draw much at all. (less than an amp with all turned on)
I have a 400 AH bank and the reefer draws 7 amps at almost 100% duty cycle in the heat of summer. that is 7*24=168 AH a day or just a little over a day before I get to 50% on the bank. even less after a few days of crusing as I don't leave the motor running to get a full charge. Course in the fall and spring it hardly comes on at all.
You have one battery of undefined capacity which makes giving a definitive answer impossible but presuming it is rated at 100 amphr, you have 50% or 50 amps available at a full charge. In other words, it's impossible to envision "draining" the battery in 4 hours regardless of what autopilot you have. There has to be another issue at play here.
Sounds like you have a weak battery. We are consious of power consumption aboard and there are a few things that we do to help conserve. If the refrigerator has been off we pre-cool it on shore power for a couple of days before going out. If just going out daysailing well use a cooler and ice. A full refrigerator works more efficiently than a partially full one. The autopilot we only use when needed, meals, bathroom breaks, radio operation, repairs and streching breaks. A well trimmed and balanced boat will use very little AP power as the rudder corrections will be light and short. I'm of the school that as long as you have to stand watch you may as well steer the boat. When we motorsail we may engage it more often as the batteries are receiving charge from the alternator.
I agree with Don and Benny, sounds like you've got a real bad battery. I've used AP, instruments, refrig., stereo, etc. for extended periods of time and never come close to draining the batteries and this was with old batteries that came with the boat when I bought it.
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