Solar charging Question

[Beach]

Bought a used Hawk last October, with a 50 watt solar system. When the solar panel is charging the house battery(optima AGM) I'm seeing 14.8 - 15.2 volts at the battery terminals mid day. The charge voltage seems a bit high, I thought the charge system was regulated and was expecting to see 13.8 to maybe 14.5 max. Have any of you checked the volt output for this, is this normal?. Thanks

 

[NorCalSteve]

Others probably have more experience than I do but I think that would depend on your charge controller. I have a Mornginstar Sunsaver MPPT controller and I don't often see it above about 14.4 to 14.7 tops. Temperature may also be a part of the computation. 15.2 does seem a little high.

Steve

 

[Wandering Sagebrush]

Bought a used Hawk last October, with a 50 watt solar system. When the solar panel is charging the house battery(optima AGM) I'm seeing 14.8 - 15.2 volts at the battery terminals mid day. The charge voltage seems a bit high, I thought the charge system was regulated and was expecting to see 13.8 to maybe 14.5 max. Have any of you checked the volt output for this, is this normal?. Thanks

Check your settings (and documentation) on the controller. I'm going from memory, but I believe 14.4vdc is an appropriate setting for an AGM.

Edit: two answers here. I checked the Zamp system on my Airstream. It has 14.4vdc for AGMs, and 14.7vdc for flooded batteries. The Morningstar controller on my Granby specifies 14.1vdc for AGMs, and 14.4 for flooded batteries. Interesting differences.

 

[The Next Adventures]

I have a die hard platinum 31m (agm) with a morningstar mppt controller, as I look at my morning star remote meter right now it says my max vdc has been 15.08.

 

[norcalhawk]

I have two, 1 1/2 years old AGM (27 series) batteries wired in parallel inside my 2012 Hawk. Last week, I was camping on the Wild and Scenic Rogue River near Grave's Creek. It was hot with full sun shinning down on me. Thought I would pump up my batteries, so I hooked into my portable solar (80W) system for a few hours. Inside monitor was registering 14.2. After a while, I disconnect my solar and within 30 min., if not sooner, (nothing was on except the refrigerator which I had on propane) my inside monitor was down to 12.7-12.8? Should the charge drop that much and that quickly?

 

[ntsqd]

In order to charge the charging source (alternator, solar controller, etc.) has to exceed the battery voltage in order to 'force' more amps into the battery. So yes, it is normal to see the system voltage drop when the charge source is turned off or disconnected. Your battery's specs should list the voltage for a full charged battery. The battery will need to sit for a while after charging with no load on it before the voltage reading will be an accurate indicator of state of charge.

 

[norcalhawk]

ntsqd, Thank you for your reply. This explains why my battery charge dropped. Guess then my batteries are OK. I am thinking of installing a 80W-100W solar panel on the roof as well. This way my bases are covered.