Charging Boat Batteries with MorningStar ProStar-Mppt
A few weeks ago, I had this “epiphany” that was going to solve a major convience project that I wanted to do for years. I have a covered boathouse sitting over the edge of a lake having a couple of boat slips with a contiguous decked “social” area. I’ve always wanted to be able to charge the trolling motor batteries and have nighttime lighting via PV solar panels, but where/how to house (and maintain) the equipment and batteries was more of a problem than I was willing to try to solve. Not to mention the cost. But things change. I’m getting older and lugging 60# batteries for a 1/4 mile puts a real bummer on the fishing experience. So now, I’m also a bit bummed-out with using my Honda 1000 generator to charge the batteries at the boat dock until the fuel runs out every time after I go fishing.
I now have a small aluminum pontoon boat that runs entirely off of 12volt battery power. The trolling motor will pull about 55 amps full-wide-open thus the marine battery currently on-board get to a fairly deep SOC in short order. I’m looking to mount a couple of 6v golf cart batteries to upgrade. The “epiphany” was that I would use the pontoon battery bank to power both the boat as well as the LED lighting.
After a rather awkward start with receiving damaged solar panels, the installation is pretty much complete - I’m waiting to receive a few odd ball type 10awg 3/8” stud connectors to hook-up the battery bank charging terminations.
did not didBefore I get to my questions, I want to comment on the service and reliability that the NAWS host for this forum provided on this particular solar installation. I’ve done business with NAWS over the last 5 years and have used their technical expertise in refining PV design and then providing most all the parts and pieces on two (2) fairly large off-grid solar installations on my property. The first was a 4.6kW (expanded to 6.1kW) and the other was 8.2kW. They were very helpful and professional every step of the way. On this current installation, the panels I received (2 ea- 320w) were damaged by the shipper and was unknown at the time we unloaded them. NOTE: In spite of all the flags, all the numerous highly visible warning labels on the packaging, the e-mail notices insisting on inspection, we failed on our end to comply with the instructions. I did not know the panels were damaged until after almost 4 weeks after receiving them, right before I was ready to mount on the roof pole. I called NAWS and within a couple of days they shipped me replacements for only the cost of the freight. They weren’t the same panels I originally ordered, but they were the same total wattage/type and I was more than pleased with this exchange. I will continue to do more business with NAWS in the future.
Now my concerns and questions. As usual for me, as I was reading the fine print on the MorningStar PS-MPPT installation/owners manual in preparation for the system start-up, I ran across a statement that read something to the effect: “before disconnecting the battery source, disconnect the PV array FIRST or serious damage could occur to the charge controller”. If this is the case, I will not be able to have a simple process of disconnecting the battery (via locking socket on 10awg cable tether) and casting-off into the wild blue. My questions are: anybody on the forum have any idea what the potential damage would be that concerns MorningStar? Is it the shut-down sequence? What if the battery disconnect is only for milli seconds as it transfers to another 12v source? I have designed a “switching box” to select between two battery banks (regular 12v marine battery) and anticipated switching to the other source when out on the pontoon boat.
System 1: PV- 410w Evergreen, Mppt- Blue Sky Solar Boost, Batt - 225ah Deka AGM, 12v led house lighting,
System 2: PV- 215w Kyocera, PWM - Morningstar PS30, Batt- 225ah Deka GC's, 12v led house lighting, Dankoff 12v water pump,
System 3: PV- 1.5kw Kyocera, Grundfos 11 SQF well pump, 3000 gal above ground water storage, dom water & irrigation,
System 4: PV- 6.1kw Kyocera, Mppt- Outback FM80-2ea, Inverter- Outback FX3648-2ea, Batt- 804ah GB traction, Grundfos BMQE booster pump 240v, Mitsibushi mini-splits 240v, 18k and 15k