Solar Charge Controller

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Does it have adjustable voltage set points? Does it have a temperature sensor on the battery bank? Those two items are important, if not essential especially for an upgrade.

mlts22 wrote:
What voltage is the panel?

Around $140 on Amazon gets you a ZAMP ZS-30A, a five stage PWM charge controller with a decent display. $280 gets you a Blue Sky MPPT controller with similar functionality.

TomG2 wrote:
I realize that 400 watts or more is preferable, but it would seem to me that us folks with the smaller systems need to know our supply and demand as much or more than the folks with hundreds of watts at their disposal. We really need to manage our usage.

Perhaps you would be better off with a battery monitor that keeps track of battery usage with a number of displays including SOC.

About $200. Mine was free considering I moved it from the last rig. :B

So invest in a volt meter and an ammeter. Far cheaper than a controller.

TomG2 wrote:

pianotuna wrote:
Upgrading the controller to have a display is not terribly useful. With a 100 watt panel ...snip......

I realize that 400 watts or more is preferable, but it would seem to me that us folks with the smaller systems need to know our supply and demand as much or more than the folks with hundreds of watts at their disposal. We really need to manage our usage.

What voltage is the panel?

Around $140 on Amazon gets you a ZAMP ZS-30A, a five stage PWM charge controller with a decent display. $280 gets you a Blue Sky MPPT controller with similar functionality.

I am a fan of MPPT controllers, but the ZAMP is good enough to be stock in almost all Winnebago installs.

The main reason I recommend MPPT controllers is that if you have a panel under the recommended voltage for charging, a PWM CC won't charge the batteries well since it can't boost the voltage. If you have a panel that has 24 to 48 bolts, a PWM CC will "lop off" all the voltage it doesn't need, so in theory, a 100 watt, 24 volt panel will be turned into a 50 watt panel. A MPPT controller can buck or boost as needed. However, the downside of MPPT controllers is the cost.

pianotuna wrote:
Upgrading the controller to have a display is not terribly useful. With a 100 watt panel ...snip......

I realize that 400 watts or more is preferable, but it would seem to me that us folks with the smaller systems need to know our supply and demand as much or more than the folks with hundreds of watts at their disposal. We really need to manage our usage.

Upgrading the controller to have a display is not terribly useful. With a 100 watt panel even in the best part of the year you will be in a deficit situation. The system may nicely recharge the battery bank between trips--which is a definite plus.

If you do upgrade, make sure to get a unit that has a temperature sensor on the battery bank and adjustable voltage set points.

hall effect thread, amp & volt meter
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/28836478.cfm

controller
VS1024BN or VS2024BN