Batteries for Solar/Wind?

[Ireland-or-bust]

all the ads i see say i need DEEP CYCLE batteries for charging and
use with solar/wind.

I heard someone say these were in UPSs ?
But the ones in UPSs are standard sealed lead acid batteries.

Are they the same thing with a different name?
If so, will any NiMH battery be ok if the voltages match etc?
How about Lion batteries?

Any why NOT car batteries?

Thanks,

Mark.

[Muddypause]

These battery FAQs may help

http://www.mpoweruk.com/leadacid.htm
http://www.uuhome.de/william.darden/
http://www.batteryuniversity.com/

[Martin]

"deep cycle" is another of those much-used and abused terms
A car battery is designed to be kept fully charged most of the time, and to be able to deliver high amperage for a short burst for the starter motor - it doesn't need deep-cycle abilities, so for cost reasons, they don't build it in!
For most renewable energy needs, a car battery will last a few weeks at most if "deep cycled" making them hopelessly uneconomic - you do need true deep cycle abilites.
In practical terms, that translates to the most cost-effective being either flooded deep cycle lead acid batteries, or advanced glass mat sealed batteries -
Flooded cell batteries are tolerant of overcharge, but will need topping up from time to time, and are not the best for really deep discharge (I'd never design to go lower than 50% discharge, and then only very infrequently)
Advanced glass mat batteries cost around 50% more, can be discharged down to 20% of their capacity, need no topping up, and will probably last at least twice as long as the flooded ones, but they really dislike overcharging, so you need a very good controller to feed them.
Manufacturers are coy about performance figures, but if you take a standard AGM battery, it will probably claim something like ~"300 cycles to 80% dod" (depth of discharge), which means you can take 80% of the power from it 300 times..........(if that's daily, that's a year!) - at lower discharge levels, the life extends considerably - it's a simple maths thing
300 cycles to 80% dod
or 2400 cycles to 10% dod - and pro rata!
As a rule of thumb, we design systems to take a maximum of 10% of the battery bank's capacity during the average day
Hope that helps a bit - it's actually a fairly complex subject!

[Ireland-or-bust]

Hi,

Thanks for the links and the info.
Having read up a bit it makes more sense.
I see that the deeper cycle batteries have a thicker/wider lead element
to enable it to withstand the hydrogen/oxygen conversion/reconversion.

So that being now said...

Here is what i'm looking at buying..

On ebay i see a 200w at 6/ms turbine.
I can get the full kit inc turbine, controler, tower, guys and a 300w invertor for £300 plus delivery. The convertor is about enough for my
lighting circuit but i'm not banking on using it.
My lighting load for the whole house is now 200w with everything turned on. Applying the law of diversity, i'd say i would not likely exceed 150w.

So my load being 150w at 220v used for say 8 hours per day would take 5.5amp hours. So what would you think i would need battery wise?

And would the turbine be enough?

Mark.

[nick1979]

I found these guys particularly helpful on sealed lead acid battery advice

http://www.thesafetycentre.co.uk/

[iks]

Forget about batteries. We have now a better way to go and its called grid tie inverters.

You don't need those environment damaging batteries. After all dead batteries are more damaging than using energy from the grid.

With a grid tie inverter you just take the wiring to the inverter and plug it in to the wall and thats it.

you can refer to wikipedia for more information.

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

here is a picture of a grid tie inverter

[Odsox]

The only problem is you're comparing chalk with cheese

A grid tie inverter is not a lot of good when the wind doesn't blow or at night if you have PV panels.
Also a complete waste of money if you are off grid as some people are who post here, plus they are hellishly expensive compared to recycled UPS pure sine inverters and need a certified electrician to wire them up.

But I agree it's an ideal "set & forget" system for non-technical people.

[dave45]

And grid-tie inverters usually cut out (for safety reasons) if mains power fails don't they?

so that you don't kill the electricity company's repair guy who is expecting a dead circuit.

[iks]

Odsox I was not comparing. I was just suggesting and alternative different to batteries. Obviously this is not for of for people who live of grid but most of the people uses solar and wind as supplement (or that is the case in US) and batteries are very expensive. Also the grid tie inverter is easier to use and less environmental damaging. Batteries produces toxic fumes while in use that could harm you and when batteries get dead what you are going to do with them?

dave45 what you say is true it is just a matter of safety.