battery health

[windspeed]

my 24V 10 ft starts to charge at very low wind, dont know exact speed

on calm days it will put out 1 to 2 A all day

the volts hover between 25 and 26. my controller is a tristar 45

I was wondering does this level of charge do anything for my batteries

another questiom I want to size an inverter for my system I have 700 ah of battery

I would like to heat water via 2kw element I figure the inverter will draw 70 A

how long will I get in real life  at this rate  assuming 90 % inverter efficency

I was thinking 2.5k inverter or higher as I intend to build a 20 ft in time

windspeed

[dnix71]

There are more direct and easier ways to heat water. Storing electricity in a battery to run an inverter is very inefficient for that purpose. Even if you never had sun and had to heat water that way, you would be better off running your water heater as the dump load from your windmill.

Direct solar water heating with a small pump run from batteries is much simpler. If you have an indoor storage tank for hot water you could make enough to last for a couple of days without sun.

http://en.wikipedia.org/wiki/Solar_hot_water

[spinningmagnets]

Cycling your batteries deeper than neccessary, or more often than needed is inefficient. Because you're using electricity for a feature where it's possible to accomplish your goals another way, it will wear out your expensive battery faster.

There's some good ideas over at "builditsolar.com" that show many ways to solar pre-heat water from salvaged junk (even in winter) so the water heater barely runs at all. Whatever you choose, best of luck!

[Flux]

A 10ft machine will do some reasonable heating on a good site on windy days, but on the days when you are producing an amp or so just forget heating. You may make a few cups of coffee a day but that is all.

There is no reason why you shouldn't dump excess power directly to heaters on windy days rather than waste it, but Otherwise heating is not a reality.

Heat is the lowest grade of energy, 24W driving a computer or a light can be very valuable but 24W into a water heating system is lost.

Your machine will gradually charge batteries at 1A or so but with a large battery bank you will largely be replacing the internal losses. 26V is under float voltage . When you see 28v you are coming near a reasonable state of charge.

No real power in wind turbines on calm days, you have to get up to 30ft or more to even see reasonable power in light wind.

Flux

[windspeed]

Thanks to all who replied to my post

all very useful , I cant dump to my my water heater as it is to far away ,80 yards

but I am inclined to agree with your points on water heatig via an inverter,

I was only thinking about doing it in the short term as I am in the process of

buying a German made air to water heating system (anyone have any ideas on these units) I plan to run the pumping loads of my turbine.

 rouhgly how much ah would I need to run a 1kw load for 4 hours every day I have average wind speed of 13.5 mph

thanks ......windspeed