Forum Discussion
mike-s
Jul 17, 2016Explorer
Just to back that up with documented, authoritative facts: Exide(1), for all lead acid battery types, specifies not only a voltage limit but also a current limit for trickle charging ("charge maintenance during extended storage"). That limit is 0.4 the I20 rate. For an 80AH Group 24 dual purpose battery, which is quite common on small TTs, that limit would be 1.6A @ 13.5V. Trojan, a well respected maker of high quality deep cycle batteries, specifies a float voltage of 13.2 V for a "12 V" system.
Zamp doesn't publish IV information for their panels, but the specs(2) for a typical 50W panel (Renogy RNG-50P) show that it puts out peak power at 17.8V/2.84A. This is under ideal conditions but it would easily be able to exceed the battery limits even under typical conditions.
Claiming a 60W panel doesn't need a controller is simply irresponsible.
(1) Exide battery charging and storage guidelines
(2)
Zamp doesn't publish IV information for their panels, but the specs(2) for a typical 50W panel (Renogy RNG-50P) show that it puts out peak power at 17.8V/2.84A. This is under ideal conditions but it would easily be able to exceed the battery limits even under typical conditions.
Claiming a 60W panel doesn't need a controller is simply irresponsible.
(1) Exide battery charging and storage guidelines
(2)

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