Long run times with SLA?

[psykosonik]

Guys,

Looking for a descent amp that will happliy run 2x10-60w bookshelf speakers which are rated at 85db@8ohms. Using no bigger than a 7.2Ah 12v SLA for around 10 hours.

The primary application for this amp is playing outdoors listening at low levels for camping.

I am looking at purchasing the Trends TA-10.1 AMP but its rated at 12v, 3A. but would only run for 2.5 hours using the formula Ah=ampxhrs.

I have searched everywhere and couldnt find a solid answer to which amp would be suitable. Can provide some reference to the ampre readings of tripaths?

I think something with efficientcy around 400-700mA would be great

Thanks in advanced!

[DcibeL]

Originally posted by psykosonik

I am looking at purchasing the Trends TA-10.1 AMP but its rated at 12v, 3A. but would only run for 2.5 hours using the formula Ah=ampxhrs.

Hehe, this is not Class A...12V@3A for the Trends amp is what the power adapter is rated for, not the continuous power draw. Power consumption will be dependant on power output, ie how loud you crank it. Under normal listening conditions, expect only a few Watts into your speakers, a few watts plus some more from the power supply due to efficiency of the amp. Also note that the lower the output power, the lower the efficiency because idle current starts to dominate the power consumption of the amp.

Also look here for further information on understanding battery life expectancy. This was the first link I found with a simple google search (remember that "have you searched?" button you checked when posting? ).

[psykosonik]

Thanks Dcibel,

Yup I did search and read how to calculate how long a battery would last, but what I didnt know was the power draw from the various tripath amps.

I got confused as some amps like the SI amp could run off batteries for a long time and other amps specs were higher (not knowing that they were rating the power adaptor.)

So you think I should be fine choosing any Tripath amp and expecting them to draw around 200-400ma @ low volumes?

p.s I just realised I need more sensitive speakers... bummer!