Originally Posted by FamilyFun
Thanks for the responses and your patience with me while i try to understand all this.
Brian, you said the solar regulator looks after the battery charge and not the converter....is this true even you are plugged in to shore power? If so, then I just need to understand how the solar regulator charges the batteries and I can ignore the converter?
I won't go into the details of why I think our batteries aren't getting fully charged since I did this a couple weeks ago in a thread, except to say that our last four trips started after being plugged in overnight or longer, which I would assume would fully charge the battery. After driving about 4 hours and arriving either in deep shade in the evening or at night (and having absolutely nothing turned on in the trailer), the voltage on the solar regulator showed around 12.5v and the charge percentage was 88%. I would think fully charged batteries would stay fully charged while travelling with no load so I am trying to understand what might be happening. I have checked everything that Reace and all of you suggested, but I haven't had a chance to use a voltmeter yet.
Here are some things which I have learned which might help you
(1) The WFCO converter/charger will not charge your battery fully unless the trailer is connected to shore power for quite a long time
-- we keep ours connected at home all the time, and right now the voltage is about 13.8 volts. This converter will not
do a "quick charge" if you connect it for a few hours. This may be a reason that some people have opted to use a different method of charging their battery.
(2) The state of charge shown by the GoPower solar charge controller is based entirely on voltage
. It does not
take into account whether the battery is being charged or discharged and has no way of knowing the amp-hours in or out of the battery. The state of charge indicated will be approximately correct if the solar panel is not charging and the battery has been at rest without any charge or discharge for several hours. This might happen in the evening or early morning when there is no sun and you are not using any power.
(3) You can get a more accurate estimate of the state of charge of the battery is you check the specific gravity of the battery cells with a hydrometer or if you use a battery monitor such as the Trimetric TM2025 which I use. The monitor measures the amperage between all loads and charging sources and calculates state of charge based on the last fully charged event.
(4) There is quite a bit of mystery about the proper charging voltage for deep cycle batteries. According to Bob (the link you provided) it should be over 14 volts to ensure the battery is fully charged. Neither the WFCO nor the GoPower will normally charge at this voltage. Bob recommends a Morningstar solar controller, and a Trimetric battery monitor. So far I've only followed one of his suggestions.
You said your battery didn't appear to be fully charged when you arrived despite driving for four hours. My guess it was not fully charged when you left home
despite what the solar controller told you. The 12 volt connection between your vehicle and your trailer will not fully charge a battery in four hours.
As others have recommended, you can get an Equus battery monitor and make sure your battery is plugged in for a long time before leaving home
and that the monitor shows a voltage of 13.7 volts or more.
If this is not possible or convenient (if you don't normally have your trailer parked close to where you live) you could get an intelligent multi-stage battery charger and use it before you leave to get the battery fully charged.