Battery charging

Multi-stage chargers will start at bulk charge, where they are usually current limited. Once the battery voltage reaches the absorption level (in the 14.6 to 14.8 volt range, the charger should switch to voltage limited, and monitor the current being absorbed by the battery. Some chargers will just set a timer and run at the absorption voltage for a couple of hours. Smarter chargers will watch the current until it reaches a pre-programmed level (to indicate the battery is "full".

Once that level has been reached, the charger should switch to float level, which is going to be in the 13.5 volt area.

You can calculate the power of the WFCO charger by multiplying the maximum current (55 amps), by the peak voltage at the end of the bulk cycle (~~ 14.7 volts). That is about 800 watts.

I sometimes use my camper for extended living, and/or traveling. I want AC when I need it. I have two Honda generators. Problem solved.

Originally posted by Olddawgsrule Well, I'm so far past this now (this was back in 2017) and never did buy a 'geeny', I've had no need. Between the solar I added and the DC/DC charging (from the TV). Good power management, solid quality batteries have done it for us!

Jato, just a comment, take it or leave it.

I don't think you will like the deep cycle golf cart batteries. They will need more charging over the winter (higher self discharge rates) and won't last anywhere near as long as what youre replacing (higher internal corrosion rates).

I recommend the deep cycle golf cart batteries for most folks who aren't paying close attention to their battery state of charge because they tolerate low SOC well. But you watch your batteries like a hawk and don't have that problem.

So my recommendation is to stay with what has been working well for you for the past 10 years. Just my $0.02.

I get the idea of using heavier batteries to increase tongue weight.


Good questions.

I'll refer you to Trojan's maintenance instructions for self discharge and frequency of recharge. They're saying 4-6 week intervals but it might be longer for you because of your cold storage conditions. Google "Trojan battery users guide" and download the PDF.

For cycle life vs depth of discharge take a look at the curve in the attachment from Northern AZ wind and Sun. This is generic but should be ok for pretty much any GC deep cycle battery

Bear in mind that just because you shallow cycle a GC battery doesn't mean you'll actually get thousands of cycles out of it as the curve indicates. That's because it is running down it's clock on shelf/corrosion life at the same time as it's running down it's cycle life. Whichever runs out first, that's the end of life. In other words, I doubt you'll get more than about 5 years of life out of GC batteries even if you don't cycle them at all, and probably not even that long. It's all really a trade off between cycle and shelf life.

cycle life