Been reading about batteries.

[Electron Pump]

  Up to this point I skimmed over seeing this abreviation. Now I am tring to get a more technicial understanding of batteries. I've been reading from the Battery University. I am gathering that it is to do with the amount of charge/discharg. I am afraid I am missing something important here.

[mettleramiel]

C rating refers to how many amps the battery can continuously discharge. If a battery is rated at 20ah and has a c rating of 1, then you can continuously discharge 20 amps without any ill effects. If it had a c rating of 2, you could draw 40 amps. This rating is mostly used in Lithium based batteries where it's important to know if you can have large draws for different lenghts of time. Here, everyone's using Deepcycle Lead-acid batteries which generaly shouldn't have more than 10%-20% of the ah rating drawn through them.

[Electron Pump]

  Very Good then, I appreciate your comment. You've helped me out in my studies.

[fungus]

That's not how I've known it ..

Usually it's written C/20 or C/10, say you have an Ah rating of 100Ah at C/20, that means that if you're discharging it with 1/20th its capacity, ie in 20 hours it will be able to supply 100Ah .. but that same battery discharged to zero in 10 hours will be able to deliver less energy with a higher discharge rate .. might be (say) 90Ah ..

[mettleramiel]

I know what you are talking about, however, I've never seen it written like that. When I see it, it's always written as "100 AH / 20H"

Well, regardless of which one it means, neither definition really aplies to solar or wind that much, since everyones generaly gets huge banks where both the draw and charge put on them are rather small.

[Bruce S]

Electron Pump;

Sorry for coming to the party so late:-) work gets in the way from time to time.

The "C" rating is actually for ALL types of batteries, and refers to both charge & discharge ratings. For charge, it's how much of a Max charge they can take before heat becomes a real factor. NiMh can take a 1C charge, but will quickly heat up.

Think of the "C" rating as the divider if your trying to "use" a battery, best not to discharge it any faster than the "C" rating; if you're trying to recharge a batt best not to try and force a charge more than "C" rating.

Keep reading on the website of Batt. U. They are so good at what they do, we bought the best 'tester' they had, and it's saves us $$$$$ each year. Came with the book too,:-).

Keep Smiling;

Bruce S

[Electron Pump]

  Thankx Bruce. I'm going to keep up the studies.