[jack russell]

Hi Zak

Thanks for the time you took to explain that

I will look at this a bit more closely as i have too give it a go.

with what you said above about ( Ahr) then a typical caravan light12v  or similar will use very little of the power stored in a typical day. for the short period of time you would need an indoor light,  on a dark plot in the middle of nowhere but could power a radio for a few hour while you dig,mmmmmmmmmm it gets better

cheers

jr

[Zak the Rabbit]

thats it, spot on. Lets say its a 12w bulb, that takes an amp, so a typical car battery would last around 30h. But, you may only have the light on for 15min so it would last 120h. During those 120h the generator, although not constant output, lets say gave full output of  1A for 30 of those hours, its more than refilled the battery! in fact, much of the generated energy will have been dissipated without being stored, simply because the reservoir is full!

Im going today to wire up the power feed from my solar panel and 7Ahr battery, to my weather satellite system. The solar panel in summer sun is rated around 6-8W. Should be ample duty cycle for what i need.


Be interesting to know on here if anyone does get a mock up wind genny going

[Axe Victim]

in fact, much of the generated energy will have been dissipated without being stored, simply because the reservoir is full!


...but where does it dissipate? Does the battery get warm and the hydrogen bubble off?...basically it would be getting trickle charged whenever the wind blows...is there some sort of switching device that stops you over charging the battery?

 :?

[Zak the Rabbit]

once a battery is full, it will only draw a low current 'maintenance charge' or trickle charge as its commonly called. The battery determines what current is taken, regardless of what the generator can supply. The excess energy simply becomes heat within the mechanical moving parts and the resistance of the circuit.

As such, the battery can be left to trickle charge indefinately, this in fact is a good idea as it stops the battery from self-discharging (that is, going flat on its own)

A lead acid battery will only become overcharged if it is charged at too high a voltage, hence the use of a regulator to keep the voltage to either 13.8v (trickle) or 14.4v (fast charging, not to be left at this voltage permanantly), if a battery is heavily discharged, it can try to draw a very large current from the charger, and so a resistance is included in the circuit to limit the available current and prevent damage to the circuit in this case.

Of course, with a wet battery (car type lead acid) you should carry out normal maintenance, making sure the electrolyte is topped up etc. Something i hadnt done on my scooter and found out this afternoon when i tried to start it that the battery is flat! :cry:

NOTE : all this about batteries relates to lead acid (car battery) or sealed lead acid (leisure batteries) only - nicads, niMH and LiIon batteries are entirely different!

[Axe Victim]

I had assumed we were all thinking of 'old car batteries' (being tightwads, green, and thinking it was all we could get hold of! )....it's all I was thinking of...simple windmill....dynamo...car battery...power....I had sort of forgotton that technology had moved on.

What would be the simplest, cheapest and most attainable set-up for an old allotmenteer?

 :roll:    :shock:

[denbo73]

My mate down our site has solar and wind power, he runs a fridge,a small tv, a cd player, and two whopping lights, He said it cost him next to nothing to build, so when he gets back from woofing in the derbyshire hills i might have a good look at his set up and get some wind and solar power in me garage, And will get some pics posted with info of course.
P.s he has got a queen wood burning stove to, for his rabbit and pike he likes to cook :roll:

[Eristic]

Does anyone know if the propeller can be made to work efficiently on a horozontal plane?

[jack russell]

hi denbo

ask your mate if i can move in that sounds better than my digs  

nah really, get some pics so we can see his set up sounds very good.

cheers

jr

[Zak the Rabbit]

Does anyone know if the propeller can be made to work efficiently on a horozontal plane?

no, the propeller needs to be vertical to ensure a sufficient volume of air passes it. The only 'horizontal' form that you can use, does rotate on a horizontal plane, but it very tall to get the air volume, they are commonly used as rotating signs outside garages!



anyone know a good cure for laryngitis? :cry:

[MontyTom]

just another thought, going back to the question can u keep the battery on trickle charge without damaging it , would it be possible to run a invertor so now producing 240v and run this on a daily basis without killing the battery?

I would suggest you use a 'leisure' battery (carvan type ones) with a reasonbly high Ah (amp hour) rating, as these seem to handle being charged and discharged far better than a car battery.  I have an 80, and two 40Ah's wired up to my panels.

Life expectancy of a battery will depend on how much you use it really, and what condition you keep it in, i.e. fully charged and fully run down from time-to-time.

[muntjac]

eating half dozen oranges slowly over 24 hours wil fix ya gitus  

[Zak the Rabbit]

Monty is pretty right there, use leisure batteries as these are designed for long charging periods on trickle, and shorter, but still quite long steady discharge. Car batteries are designed to be kept charged by the cars alternator, but discharged only for very short, very deep periods (ie starting). if working properly all the cars electrics are powered by the alternator when the engine is running.

leisure batteries are what i (and the industry) know as Sealed Lead Acids. They come in a huge variety, from the 40/80/120 Ahr big units used on electric vehicles/mobility scooters and big computer UPS's, down to the small ones used in alarm systems, at maybe 6v 2Ahr. I use 12v 7Ahr for my solar kit cos my panel is only small and my radios dont need much.


oh and muntjak, i dont like oranges :cry:  so its been cavonia, menthol, and lemonade, oh and a few black sheep!

[Bigbadfrankie]

I have been looking into wind power to. Its very interesting. Also surprising how little electric a windmill makes even if its windy!!!.

any how another site

http://www.scoraigwind.com/books/  

http://windstuffnow.com/main/


These are interesting if not demoralizing

[Bigbadfrankie]

Does anyone know if the propeller can be made to work efficiently on a horozontal plane?

There is a windmill which work upright (Deralious i think) but it has to be started. The wind will not start it spining but once going its omnidirectional and all the working gizzmos are on the floor. Saves having slip rings or wires wound around the support pole :idea:

[MontyTom]

Just wanted to add that I found a great site for wind/solar stuff called solarwinds.  I have been after a mast for my turbine for ages and they have them there for a reasonable price.