Formula for charging time of 12v battery

I have a Powerpack 300, which is a 12v battery at 12Ah.

Using the AC adapter with the house outlet (20amp at 120v) it takes 17 hours to fully charge the battery. How would I calculate the (approximate) time it would take to charge the battery, using a solar panel that draws 1amp at 15v (DC)?

"Northern Night Sky"

Any such predictions would have to involve detailed knowledge of the local weather, cloud cover and solar illumination levels.

Wouldn't it ?

.... Phil

The specs give a max expected charging time of 24 hours with nominal wall voltage and the supplied AC adapter. Since it looks like the adapter puts out DC and also that the charging circuit is a "smart" charger, then the time using the solar panel would be similar.

You still can get an approximate time of how long it would take to charge the battery, giving the variables I've provided...Duh! If I get 5 hours of sunshine/day, then I'll do the math in consequence. I'm still interested on getting the FORMULA, as per my original question.

"Northern Night Sky" "Phil Allison"

You still can get an approximate time of how long it would take to charge the battery, giving the variables I've provided...

F*ck off, imbecile.

.... Phil

cal

The 12Ah is the capacity of the battery. 12 amp x hours. So if your solar charger provides 1 amp, then it will take about 12 hours. (Assuming the battery is fully discharged at the start.) What was the current rating on your AC adapter that took 17 hours?

george h.

cal

wow, what a typical answer from a Google Group! Your first answer was passive-aggressive, at best. Then, your second is even worst. Instead of telling me WHY it cannot work and educate me, you thought it was a more logical and rational ideal to tell me to "f*ck off". I don't think you know nearly as much about the subject, as you claim.

If the Maximum charging power is 1amp at 15v, on a 12Ah battery, I'm sure you can calculate the charging time.

Maybe I should go to some place more professional!

ar

local

THANK YOU George! The specs of my adapter are:

Input: AC120V 60Hz 16W Output: 13.5VDC 500mA

on 10/02/2011, George Herold supposed :

The charger according to the sales blurb supplies 500ma. The 20 amp 120 volt house outlet is useless and probably wrong information. Is not the normal US outlet limited to 15 amps?

"Northern Night Sky"

local

ur

I neglected to consider the adapter rating. You're right, it's a 15 amp outlet, in a 20 amp circuit.

This a Usenet newsgroup, not a 'Google Group'. Just because you access it through Google doesn't make it theirs.

Phil is mentaly ill, but once in a while he's right to tell people off.

Not necessarily. You can't just stuff a constant current into a lead-acid battery and expect it to be happy -- the usual method is to charge it at a constant current (depending on the charger's capabilities) until the voltage rises to about 2.4V/cell (with the exact amount depending on the battery and the ambient temperature) then holding the voltage constant and allowing the battery to accept as much charge as it can at that voltage.

Actual charge time then varies with both the charger's ability to deliver high current at first, and the battery's ability to absorb it later.

I assume you mean that the solar panel _delivers_ (not draws) 1 amp in bright sun. If so, it can probably deliver 6 - 8 Ah on a sunny day.

If the battery is 12 Ah, and fully discharged, it will require about

"Peter Bennett"

But the OP is a pig and deserves only swill.

.... Phil

es 17

olar

e local

ur

No problem, At 1/2 an amp times 17 hours you put a bit more than

Phil A, knows a lot more than I do about electronics, but he's a bit.....

George H.

local

ur

er.

d text -

Thanks Tim, I didn't know that. I figured his charger would take care of the messy details.

George H.

local