Battery charging info
After living on 12 volts full-time for 8 years, I've put together a series of blog posts sharing everything I've learned about battery charging, different kinds of charging systems and the unique quir...
Forum Discussion
Thanks for the links to your good electrical information. I've read some of your blog postings before. Your writing is straight-forward and clear. Good work!
You didn't seem to mention use of AGM RV batteries .... but it's possible I missed it. They act differently because of their low internal resistance. What they do is accept more charging current from whatever charger is used whenever they're at less than full charge. This includes when attached to a single stage converter. Our AGM deep cycle batteries and our Parallax single stage converter play together differently from what your writings describe for wet cell lead acid batteries.
When our AGM batteris are low - depending upon how low - the fixed voltage converter acts as described in it's literature. It can and does supply way more than trickle currents into our AGM batteries ... with it's current flow tapering down as the batteries charge up. The converter can do this at it's fixed 13.6-13.7 volts output due to the low internal resistance of the batteries. Additionally, to prevent our AGM batteries from slowly destroying themselves by releasing their water content through their one-way valves when left continuously connected to the converter while in storage or on full hookups, we chose AGM batteries that had a recommended float voltage of 13.5 volts to 13.8 volts. Thus, our AGM batteries get both floated and charged from the converter's nearly constant fixed voltage. Of course the batteries see high alternator (we have a MH) voltage and currents between campsites, and during these times the AGM batteries absorb up to 50 amps from the alternator for short periods as we drive down the road. Four to five hours of driving will fully charge the two 100 amp hour AGM batteries if they started at no lower than around 50% discharged.
Our dry camping style is not to stay days and days at the same location. The rare times that we do, I often charge the batteries with both the converter and a small higher voltage charger connected to the batteries at the same time. The small charger raises the voltage on the batteries' terminals for even faster charging ... but both the converter and charger outputs are combining to deliver more current than either one does by itself.
If you haven't done so already, you might want to eventually try AGM batteries in your rig to get the fastest charging possible. :)
You didn't seem to mention use of AGM RV batteries .... but it's possible I missed it. They act differently because of their low internal resistance. What they do is accept more charging current from whatever charger is used whenever they're at less than full charge. This includes when attached to a single stage converter. Our AGM deep cycle batteries and our Parallax single stage converter play together differently from what your writings describe for wet cell lead acid batteries.
When our AGM batteris are low - depending upon how low - the fixed voltage converter acts as described in it's literature. It can and does supply way more than trickle currents into our AGM batteries ... with it's current flow tapering down as the batteries charge up. The converter can do this at it's fixed 13.6-13.7 volts output due to the low internal resistance of the batteries. Additionally, to prevent our AGM batteries from slowly destroying themselves by releasing their water content through their one-way valves when left continuously connected to the converter while in storage or on full hookups, we chose AGM batteries that had a recommended float voltage of 13.5 volts to 13.8 volts. Thus, our AGM batteries get both floated and charged from the converter's nearly constant fixed voltage. Of course the batteries see high alternator (we have a MH) voltage and currents between campsites, and during these times the AGM batteries absorb up to 50 amps from the alternator for short periods as we drive down the road. Four to five hours of driving will fully charge the two 100 amp hour AGM batteries if they started at no lower than around 50% discharged.
Our dry camping style is not to stay days and days at the same location. The rare times that we do, I often charge the batteries with both the converter and a small higher voltage charger connected to the batteries at the same time. The small charger raises the voltage on the batteries' terminals for even faster charging ... but both the converter and charger outputs are combining to deliver more current than either one does by itself.
If you haven't done so already, you might want to eventually try AGM batteries in your rig to get the fastest charging possible. :)
