Can I also suggest that if you're looking at increasing efficiency, that you err away from the "PWM" variety of solar controllers, and move to the MPPT version? The PWM version basically throws away any voltage above the required charge voltage by using PWM, whereas the MPPT will use a buck-boost approach to keep both the charge voltage at the desired level and the maximum draw current from the panel that it can sustain.
A few years ago I did an uncontrolled test, I had that *exact* PWM controller and a 10w panel, charging an SLA battery. I had a micro hooked up to it, logging the time and battery voltage, and having it burn some power (I had it flashing LEDs). I would monitor the time that the voltage dropped to the point that the solar controller switched it off. The tests were done on days where there was ample sun available - summer in Australia - and I ran it over about 3 weeks to get trends. I then ran the same tests with a similar MPPT controller, over similar length of time, and it was astounding the difference - instead of hitting the low-voltage cutoff at say 3am, it was making it to ~6am which in some cases was all night as the sunrise happened and kicked off recharge.
The controllers I have opted for now are similarly priced (I think). I've been buying the 5A model - on ebay the item number is 261392830593, http://www.ebay.com.au/itm/261392830593?...1439.l2649
[ And as an aside when comparing this stuff to the FO approach - they are extremely frugal with transmits and receives. At startup or when the RX and TX units sync, they get into a known TX/RX pattern. The receiver turns on when it expects to hear from the TX, and then the TX transmits and shuts down, and the RX shuts down even if it doesn't get a signal. By keeping a low transmit rate, and this closely coupled cycle, they keep the power usage extremely low. It would also seem that they have purpose-selected a processor that allows them to run interrupt counting frugally and in low power state. All of these things are possible to replicate but more complex, and usually beefing up the power capacity is an easier thing
]
Oh and another question for Werk_AG, while you're on the roof, can you measure the dimensions of that box ? It looks awesome, and I'm struggling to find one that I think matches - particularly that's UV safe as here in AU that is a real concern. I am almost expecting to pay 10x the price for that than the solar controller !
A few years ago I did an uncontrolled test, I had that *exact* PWM controller and a 10w panel, charging an SLA battery. I had a micro hooked up to it, logging the time and battery voltage, and having it burn some power (I had it flashing LEDs). I would monitor the time that the voltage dropped to the point that the solar controller switched it off. The tests were done on days where there was ample sun available - summer in Australia - and I ran it over about 3 weeks to get trends. I then ran the same tests with a similar MPPT controller, over similar length of time, and it was astounding the difference - instead of hitting the low-voltage cutoff at say 3am, it was making it to ~6am which in some cases was all night as the sunrise happened and kicked off recharge.
The controllers I have opted for now are similarly priced (I think). I've been buying the 5A model - on ebay the item number is 261392830593, http://www.ebay.com.au/itm/261392830593?...1439.l2649
[ And as an aside when comparing this stuff to the FO approach - they are extremely frugal with transmits and receives. At startup or when the RX and TX units sync, they get into a known TX/RX pattern. The receiver turns on when it expects to hear from the TX, and then the TX transmits and shuts down, and the RX shuts down even if it doesn't get a signal. By keeping a low transmit rate, and this closely coupled cycle, they keep the power usage extremely low. It would also seem that they have purpose-selected a processor that allows them to run interrupt counting frugally and in low power state. All of these things are possible to replicate but more complex, and usually beefing up the power capacity is an easier thing
]Oh and another question for Werk_AG, while you're on the roof, can you measure the dimensions of that box ? It looks awesome, and I'm struggling to find one that I think matches - particularly that's UV safe as here in AU that is a real concern. I am almost expecting to pay 10x the price for that than the solar controller !