boondocking, need help asap....

This is a brochure from progressive dynamic on how long it takes to re-charge a deep cycle battery. I suspect you are no where near getting any charge back into your batteries. This is battery science so there isn't many ways to get around the deep cycle battery charge process. Sorry...

"Progressive Dynamics ran this test on the amount of time it took a PD9155 (55-amp) converter/charger set to three different output voltages to recharge a 125 AH (Amp Hour) battery after it was fully discharged to 10.5-volts.

14.4-VOLTS (Boost Mode) – Returned the battery to 90% of full charge in approximately 3-hours. The battery reached full charge in approximately 11 hours.

13.6-VOLTS (Normal Mode) – Required 40-hours to return the battery to 90% of full charge and 78-hours to reach full charge.

13.2-VOLTS (Storage Mode) – Required 60-hours to return the battery to 90% of full charge and 100-hours to reach full charge."

The bottom line here you need to have a 14.4VDC voltage charging source with a minimum of 20AMPs capacity per battery to be able to charge a standard deep cycle 12VDC battery to its 90% state of charge in as little as three hours time. If you don't ever get the deep cycle batteries back up to their 90% state of charge then they will not perform as specified.

Please note on the brochure how long it takes a 13VDC source to re-charge a deep cycle battery... The other problem is your solar source is only 45WATTS which relates to around 3AMPs of available power. This is a good trickle charge unit for being connected to your your battery when parked at home and the rest of the trailer disconnected.

Also all trailers have a parasitic drain associated with them such as monitor broads, propane monitors, etc which by them selves will discharge a fully charged deep cycle battery in a few days if left connected. My battery system see around 1AMP of this type of parasitic drain. The way around this problem is too install a battery disconnect switch or just remove the negative battery terminal when not in use.

You should also purchase an inexpensive multimeter from WALMART-LOWES that only costs around $7-$15 which will give you exact battery terminal readings. The percent reading most trailers come out with do not do very well reading what you actually have.

just my thoughts

Well hopefully some smarter than I will chime in. Not a lot of info. 50 watt is rather on the small side for two 12v batteries, hard to imagine that batteries ever get 'fully' charged.
However it sounds by description precieved 'something' -other than stuff on- is draining batts once charge source gone (sun). The panles themselves can 'use' power-but most have internal diodes to prevent this.
The controllers do just that-control how much and when charge is sent to batteries-more like regulates charge source so doesnt overcharge the battery.
When charging removed the batteries WILL drop and stabalize back to 12.4-12.7 or so depending on charge. If your controller has LVD (low voltage dissconnect) it could be as low as 11 somthing volts, which is a discharged battery before it shuts off.. Also depending how its wired -that may/probably doesnt dissconnect camper from batteries-only the 'load' ouput of controller.

If you have NOTHING on, (but your camped?)refer board-parasitic (radios tv safety sensors) and your batteries drain there is a problem.
But it honestly sounds like batteries start not fully charge-normal in use being taken down untill indicator shows red-I dont know what the set points are on controller-.
COuld be a lot of things, like battery not holding charge-age?

Here is some reading on batteries, charging, charge levels, etc

The 12 Volt Side of Life

Measure the actual battery voltage so we know how bad is bad and how good is good.

Remove a battery cable to verify no load and voltage dropping steadily that could indicate a bad battery.

Almost 13 volts is not charged. For full charge on solar you need to see 14+ volts before it drops back to ~13.4. Under 13 while solar is producing is not near charged.

Batteries are a year old. When it says full charge (green) on controller, voltage reads almost 13v. Is that a full charge?
What would the test be disconnecting the controller? What would I look for?
thanks!

The controller is not the likely suspect.

If your batteries are old they will self-discharge more rapidly. Also, 55w is not much, and it's not likely in my estimation your batteries are getting fully charged. A voltage reading is not a very good indication of a full charge.

As a test you can simply disconnect from the controller and see what happens.

I have nothing on! I wouldn't be asking for help if I had stuff on and knew I was running it down.

As soon as sun starts to set voltage starts dropping,need to find out why. Thought that is what the controller should control, right? So why isn't it?

Moved to Tech Issues.

Wayne
Moderator

what do you have on?