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Old 31-03-2003, 01:32 PM
Martin Brown
 
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Default Solar-powered water features - any advice?



Steve Harris wrote:

In article ,
(Martin Brown) wrote:

The pumps also work well with a 12v lead acid accumulator or any
other 12v DC 2A supply.


How much do the pumps draw?


Depends how much you want to pump. The pump I had stalled on anything much
less than 8v and 1A.

Guess: 50 mA which would require a 40 AH car battery to be charged
monthly. That's a power of 0.6W let's say 0.5W after losses.


I ran mine at 14v 2A for about 10 minutes a day for greenhouse irrigation
from a big water butt.
Roughly 2 months between charging with a 20Ah lead acid accumulator
(I intended to use solar power but it simply wasn't cost effective)

Also you need a deep discharge battery - car batteries are really only
happy kept well charged for starting cars.

Regards,
Martin Brown