Off Grid Battery advice

[Optimystic]

Hi all..

Having absolutley no idea about electrics.... am I correct in thinking i can get a 12V car battery, a Power Inverter and a Solar panel trickle charger and be able to run small appliances?.. How big an appliance could you run? Microwaves? Fridges? Laptops?.. etc

Hope this makes sense

[Justin Time]

Yes you are right. with 1 battery and 1 solar panel you'd only be able to use small appliances. It also matters if those appliances are AC or DC (an inverter is needed for AC appliances)

The power (rated in Watts) that you will need take from the battery for your appliances will determine not only how many batteries you need but also how many solar panels you'll need to recharge your battery(s). Batteries are rated in Amp hours (Ah), that is the the amount of sustainable current they will provide over a period of time so the better quality battery you get, the more power you can take from it.
A small setup to begin with and a little experimentation is easy to do as these systems are very modular, you can add more bits any time you like.

heres a quick read for you Optimystic.
http://overlandresource.com/what-is-an- ... y-capacity

[Malamute Mitch]

Yes you are right. with 1 battery and 1 solar panel you'd only be able to use small appliances. It also matters if those appliances are AC or DC (an inverter is needed for AC appliances)

The power (rated in Watts) that you will need take from the battery for your appliances will determine not only how many batteries you need but also how many solar panels you'll need to recharge your battery(s). Batteries are rated in Amp hours (Ah), that is the the amount of sustainable current they will provide over a period of time so the better quality battery you get, the more power you can take from it.
A small setup to begin with and a little experimentation is easy to do as these systems are very modular, you can add more bits any time you like.

heres a quick read for you Optimystic.
http://overlandresource.com/what-is-an- ... y-capacity

Hi some of this info is right but some wrong, the Ah of a battery ie a 75amp hour battery will theoretically give 1 amp for 75 hours or 75 amps for one hour. However as I said this is theoretically, as very dependent on the 'type' of battery and the 'type' often is reflected in the price, generalizations on type (very over simplified) would be car battery and deep cycle battery.

Now again this is a generalization but the maximum amperage you can take out of a car battery without damaging it is about 10% about 7.5 amp for a 75 amp hour battery, this is why they are also rated in cca cold cranking amps, as they are designed to give out a high amperage over a short period of time. (but not exceed about 5% of total capacity ). But are not designed to give sustained amperages over a much longer period of time. When charging car batteries like high amperage charging if they are less than 10% depleted.

Deep cycle batteries are very different. They can use 30% of there charge without damage, so for a 75amp battery you can use 22.5 amps. (x3 more) but they don't like fast/high discharge or charging.

On top of this there are many hybrid s of these especially for renewables the best being 2volt batteries. So in all I've now caused total confusion but maybe an idea a long term viable system which does not see people wasting money on something that ultimately won't work is quite complicated and takes much research. I will try in the coming weeks to do a few more posts and break it down in blocks.

Umm as to website to learn more please subscribe!! yeah right

[itsybitsy]

heres a quick read for you Optimystic.
[url]http://overlandresource.com/what-is-an- ... y-capacity[/url
Umm as to website to learn more please subscribe!! yeah right

I didn't have to subscribe to the website to view the articles - if you are referring to the link posted above?

[Justin Time]

I must admit to not being an expert but yes MM, deep cycle batteries are best for solar powered setups. I've been learning what I can about the subject but it can get really boggy with maths and formula and theory...
Probs the best thing to do here for Optimystic is an example system.

Maybe start with a 100W solar panel
A 75Ah deep cycle battery
1000 Watt inverter

the maths: Power (Watts)= Voltage X Current (Amps)
1000=12X83.2

How am I doing so far? (be gentle)

[Orange5]

The maths may be right but remember a fixed solar panel will only kick out its theoretical full power for three hours a day. You could spend on a sun tracker to extend the amount of power you will get from the solar panel but these are dear. The inverters take power as well and can be quite greedy. To run a 50 watt device through one could use upwards of 100 watts. Dont forget cloudy days when your panels will only produce a quarter of its full power as well.

[Optimystic]

ur doing better than I am Justin.. i was lost at the word amp!..lol

What is a deep cycle battery?..

[Justin Time]

As Mitch said, a normal car battery is made to give a very high current for a very short amount of time, ie, to work the starter motor of your car which takes a lot to turn the engine.
Deep cycle batteries are made to do the opposite which is supply a certain amount (nowhere near a car battery) of power, depending on the Ah for the particular battery, for sustained longer periods which means they are more suited to powering our gadgets.
I guess when Mitch comes on he'll tweak the maths above and hopefully a better understanding of what 1 solar panel can achieve.
Got a feeling that that 1 x 100 watt panel defo won't sustain a 1000 watts inverter for very long obviously depending on the load (amount of gadgets), Is that the microwave out the window I wonder

[nickdutch]

The power from the solar panel should go into a solar power charge controller (you need a different kind of charge controller for wind) and then it branches off one way for a battery and another way for a "load" which is where the power goes when the battery is full.

make sure you use a charge controller. I also used blocking diodes to make sure the power wouldn't go back into the panels and torch them.

However I have to get my panel repaired as it has a solder break. i will need to be in a mental place of calm to do that.

You can then use an inverter to step up the voltage and give you the AC you need for normal appliances.

[Optimystic]

Eek.. ya knwo when sometimes theres a subject that no matter how its explained it just doesnt compute in ya brain?..lol. Thats me with this kind of thing... ill read up some more till i 'get it'! or till i can find a 'geek' willing to show me!..lol