Stacey being heard, some Panama canal backstory, and something from the “war on science” department…
I’m often confronted with the whole “you have to use this expensive marine part” rant and, so much so, I find myself even believing it from time to time. Case in point was yesterday when a connection on a solar controller came undone. My knee-jerk reaction was to think that maybe I should have went with the Victron rather than the Renogy.
As it happens, after a lot of research, I bought three of the $40 Renogy PWM Wanderer solar controllers. For our purposes, they were all we needed and, being more affordable, were budget friendly.
All in all we’ve been very happy with the Renogy controllers with only one peeve: the screw down connections.
I did consider the Victron MPPT 100/30 controllers but I prefer PWM over MPPT, and the high cost of the Victrons (over three times the cost of the Renogy) was a deal breaker. That said, I’ll also point out that Victron has the same dumb-as-a-bag-of-hammers screw-down connectors which pretty much sealed the deal.
Since yet another loose wire on one of our Renogy controllers had me cussing to blue heaven and wanting to replace the Renogys with something that had not-stupid means of connecting cables, I came across the fact that Victron has a line of PWM controllers that are affordable. Chances are it’s just a cheap Chinese brand that Victron is pasting their label on but since Victron is known for its quality, they might be worth checking out. The downside, of course, is that the Victron PWM controllers use the same crappy connection system as everybody else.
Banging head against bulkhead…
It’s not really fair comparing the price of one guy’s apple (PWM) to another guy’s orange (MPPT), but I catch your drift.
Using wire ferrules on your cable ends (if you’re not) will make your loose-wire troubles go away… with the added bonus of making the use of stranded wire in terminals so close together much safer by keeping any strays from wanting to mingle.
The problem with most of the screw down connections is that they are too small for the 10AWG most folk use for their solar wiring. Ferrules would help but they don’t address the fact that the screw downs use crap pot metal screws which can’t be torqued tight without a chance of stripping out the heads or threads.
Of course, I’m opinionated but still think a good solar controller would/should use ring terminals or a reasonable facsimile.
On the subject of PWM/Mppt Bogart has an excellent take on the PWM vs Mppt debate that you might find interesting.
All the best
I understand where he is coming from, and agree that PWM has its place… but he tosses out some dubious numbers: Victron’s 30A MPPT steals less than half a watt in normal use and more than makes up for that in its added effectiveness. His series/parallel debate ignores the greater efficiencies to be found in running higher voltages, and I suspect all of his argument revolves around the fact that he doesn’t have an MPPT to offer and is just standing up for what he has got. Just a hunch.
On boats we are always struggling to find real estate for our solar panels so getting the most out of what we’ve got with a more expensive controller is often the cheapest way to get more watts where they count.
We each have to pick our own priorities, of course!
Do you have a source for that “…steals less than half a watt…” claim? We routinely install MPPT controllers like Victron, Epever, etc and find the heatsinks to run quite hot. Additionally, we have measured the solar side voltage & current and the same on battery side and we do see numbers similarly to Bogart’s claim. BTW, Victron has whitepaper on their website authored by their CTO. On page 8, you’ll see a plot of PWM vs MPPT comparison as function of cell temperatures. The difference between MPPT & PWM is negligible during the popular camping seasons – spring/summer/fall, when panel cell temperatures can reach 60C or higher. I do agree that MPPT’s have certain advantages like simpler wiring but there’s no denying that these come at some price.
https://www.victronenergy.com/upload/documents/Technical-Information-Which-solar-charge-controller-PWM-or-MPPT.pdf