What should I use?

[who8myrice]

hello everyone,

I apologize for asking so many obvious questions (obvious for you that is) but I really need to know. What should I use as battery connectors? should I use a car jumper? should I just by heavy duty copper wire? i checked eBay and Froogle and i found nothing useful.

Also, whats a good charge controller for a 9 amp/hour, 12volt, 100watt wind generator?

Again, im sorry for asking so many questions, but im new to this stuff and I dont want to waste money, or have a crummy set up.

[who8myrice]

Oops, forgot to ask how heavy duty (what kind) of wire i should use to run the line from the genny to the charge controller

again, srry for the questions :/

[henjulfox]

The short answer to what size wire to use is the largest you can afford.

http://www.powerstream.com/Wire_Size.htm

This link goes to a nice chart of wire size and the recomended amp capacity. If you try to save money by getting wire that is too small you will waste generated electricity in the wire and potentially create a fire hazard.

Batteries in a RE system typically charge at a slow rate for a long period of time and discharge at a high rate for a short period of time. Therefore smaller wire can be used for the charging circuit (wind gen to battery) but larger wire must be used for the output (battery to inverter).

If you think 100 Watts at 12 volts is the most your generator will produce, the answer is that it would be moving 8.3 amps which calls for 12 guage wire. I've had good luck with low voltage outdoor landscape wire from the local home improvement store. If you attach a 300 watt inverter to the battery, it will pull 25 amps which calls for 8 guage wire. I would go 6 or 4 guage to handle surges and upgrades. This is common battery cable size, available at the local auto parts store.

Make sure your wire connections are solid. No wrapping around the terminal and hope it stays. Crimp lugs are great, mechanical lugs (screw to hold the cable) work well for their flexability. I suggest spending a few extra bucks at the auto parts store on getting cables that have the correct connectors already attached.

I strongly recomend reading prior postings on this site. A search on the word "battery" will give you plenty to read. At first it's overwhelming but if you keep at it the info starts sinking in and it all makes sence.

By the way, in this project, either the RE bug will bite you or it won't. If it dosen't, you will learn a lot, have some fun, and what you put together will end up in the back of the garage. If it does bite you, you will learn a lot, have some fun, and what you put together will end up in the back of the garage as you improve and upgrade your system! Therefore what's important is that you learn and have fun.

-Henry

[who8myrice]

thanks a lot henj, and when you said that a 300 watt inverter would pull 25 amps, does that mean it will pull 25 amps per hour?

[richhagen]

An amp is a unit of current measurment equal to one Coulumb of charge per second.  A single electron has a charge of minus 1.602 times 10 to the -19th Coulumbs.  Thus the current in amps is a rate of movement of the electrons.  As such, it would be analogous to a water flow rate in gallons per hour.  If you are running 25 gallons per hour of water and you leave the tap open for an hour, 25 gallons will flow.  The term used for the quantity of electrons moved that would be analogous to the gallon term for the water, would be the term amp-hour.  So, to answer your question, if you left a device connected that allowed 25 amps of current to flow through it for an hour, you would have used 25 amp hours.  One other thing to note is that the amp hour rating you see on a battery is usually the amount of amp hours that can be pulled out of it new over the course of 20 hours.  If you draw the current out quicker you will probably get fewer amp hours before the battery is dead.  Also, the deeper you discharge the batteries, the fewer charge/discharge cycles you get out of them before they are ruined.  See the battery facts page linked to from the front page of this site at www.otherpower.com.  Just as the amps is analogous to the flow rate in a water system, the voltage is analogous to the pressure.  The power is watts equivelant to the current in amps multiplied by the voltage in volts.  If you inverter is pulling consuming 300 watts to put out on the AC line (ignoring any inefficiencies which mostly show up as heat in the inverter for now) then the battery must be supplying 300 watts divided by 12 volts, or 25 amps of current.  Hope this helps, Rich

[richhagen]

OOPS, the sentence "The power is watts equivelant to the current in amps multiplied by the voltage in volts." near the end should start "The power in Watts is equivelant to"  sorry, Rich

[mikeyduk]

Try here http://www.futurenergy.co.uk/products.html

600v 75Amp cable

If anyone looks,any opinions on the blades and genny on the same page ?

Mike

[veewee77]

Yeah, too many blades. . .

Look at the big boy's units. . . they all have 3 blades. . . must be a reason for them so spend millions on units with only three blades instead of 5. . .

Doug

[ghurd]

I like the marine style battery terminals. They are usually painted red and black.

The kind that have a place for a main wire, and a smaller wire or 2.

Some are fancy...

http://www.cabelas.com/cabelas/en/templates/purchase/products-found.jsp?_requestid=12877

I often use jumper cables a wire source. The cables ($4 for 10') are cheaper than the wire ($1 / foot) around here.

G-

[who8myrice]

thanks a lot rich, it did help a lot

[who8myrice]

you use the jumper cables to interconnect the batteries? are they efficient?

[ghurd]

I don't usually use the jumper cable clamps except for smaller (3 to 6A) solar systems.

It is OK for the solar I usually do, because if it is poorly connected, or becomes disconnected from the battery there is no problem.

There will be a problem if a windmill becomes disconnected from the battery!

So do NOT use jumper cable clamps with a windmill.

I often need short flexable black and red married cable for 5 or 10 or 20A.  The #10 jumper cables provide it cheap, and easy to get.

I like the wire fine for battery connection or interconnection (as long as the amps are not too high).  Some other wire types have insulation problems from the acid vapor.

I solder the fine strands into a solid before they get put into the terminal device.

[richhagen]

Hmm, I have seen those before.  I prefer a three blade unit because, under ideal conditions, for the same diameter and operational tip speed ratio range, and given a relatively standard airfoil, the cord width, depth and angle will be greater for the three blades than for 5 or more, and if similar solid materials are used, should result in more structurally sound blades.  

If you stay away from the theory which would have you building thinner blades and build thicker blades like the first three, then while you may add more starting torque, once the additional drag of the extra blades starts increasing as the blade speed up towards the cut in speed, the actual speed of the blade set will be lower.  

If you have a formula to model the ideal blade angle and chord for a set turbine parameters that allows you to change the number of blades, you can plug in a different number of blades and see how the chord width and angle changes as you increase the blade number.  Hugh Piggot did have such a formula on his web site at one time, I do not know if it is still there.  Rich

[fred480v]

I have 300 new champion battery cables in different lenghts & wire sizes. check e- bay auctions or contact me fred480v@sbcglobal.net & this will work well for you at a very low price    fred480v