So, for the past few weeks I’ve been running a Redarc BCDC-1225 solar controller to keep the batteries charged. I initially found I had to make my little power controller back off on the mains charger a bit, but was finally able to prove conclusively that the Redarc was able to operate in both boost and float modes.
In the interests of science, I have plugged the Powertech back in. I have changed nothing else. What I’m interested to see, is if the Powertech in fact behaves itself, or whether it will go back to its usual tricks.
The following is the last 6 hours.
Next week, particularly Thursday and Friday, are predicted to have similar weather patterns to today. Today’s not a good test, since the battery started at a much higher voltage, so I expect that the solar controller will be doing little more than keeping the battery voltage up to the float set-point.
For reference, the settings on the MP-3735 are: Boost voltage 14.6V, Float voltage 13.8V. These are the recommended settings according to Century’s datasheets for the batteries concerned.
Interestingly, no sooner do I wire this up, but the power controller reaches for the mains. The MP-3735 definitely likes to flip-flop. Here’s a video of its behaviour shortly after connecting up the solar (and after I turned off the mains charger at the wall).
Now looking, it’s producing about 10A, much better than the 2A it was doing whilst filming. So it can charge properly, when it wants to, but it’s intermittent, and inside you can sometimes hear a quiet clicking noise as if it’s switching a relay. At 2A it’s wasting time, as the cluster draws nearly 5× that.
The hesitation was so bad, the power controller kicked the mains charger in for about 30 minutes, after that, the MP-3735 seems to be behaving itself. I guess the answer is, see what it does tomorrow, and later this week without me intervening.
If it behaves itself, I’m happy to leave it there, otherwise I’ll be ordering a VSR, pulling out the Powertech MP-3735 and re-instating the Redarc BCDC-1225 with the VSR to protect against over-discharge.
Update 2018-10-28… okay, overcast for a few hours this morning, but by 11AM it had fined up. The solar performance however was abysmal.
Let’s see how it goes this week… but I think I might be ordering that VSR and installing the Redarc permanently now.