I'm building a sm. tracking solar generator to use w/ my toy hauler when boondocking that can be used in 2 ways.
1)To top off the toy hauler's 12 V deep cycle battery.
2)To charge my LiPoly 12S/20 Ah main pack.
The details of the panels and how the tracking system works I will post later when I have the system up and running, but it will use 2) 50 Watt/12 V panels connected in series as one 24 V panel.
For job 1), the panel will feed a MPPT solar controller, which will function as a "buck" converter, taking the 24 V input down to the RV battery's charge Voltage
For job 2).the panel will feed the second solar controller, which functions as a "boost" converter, taking the 24 Volts up to my 12S charge range(42 V to 49V). For this I will be using this new, inexpensive controller;
https://www.amazon.com/gp/product/B01HC ... UTF8&psc=1
Here I am bench testing it, powering it w/ a 12 V server power supply and using 2) 6S bricks as a load;
As you can see, it's no power house, but it is sm. and weighs nothing . The power supply's 12.48 V output gets pulled down to 12.08 V under load putting 1 Amp (50 Watts) into the batteries. With a 24 V input I should see a 2 Amp output of 100 Watts, (somewhat less depending on the Sun and the panel efficiency. The MPPT controller is very efficient, in the mid to high 90% range).
I understand that at that rate, will take quite bit of time to put back the 10 Ah that I typically use from my main pack, but I don't see any other way to recharge it off the grid. While most of my packs can be broken down and charged using my RC balance charger running off my RV or truck battery, this main pack is built in the bike w/ no way to "break the string".
I could, of course, run the boost controller off one of my batteries overnite @ 50 Watts as the toy hauler requires little power at nite. I will test to see how much that scenario drains the lead-acid batt over an 8 hr. period.
I should have everything together for testing in several days and will relay how this works within the week.