Locally I’m seeing (second hand, allegedly new in box consignments so no warranty)
Epever 4215BN <$80
Victron 100/30 <$90
MidNite MNKID-B <$160
Panels are often in partial shade, under cloudy skies, and cold (vehicle mounted 3x 80w CIGS).
Victron proprietary Bluetooth coms for similar prices, sometimes lags, flimsy and puny connections for my nominally 10awg wiring (5.2mm2 stranded). User reports here and elsewhere, plus Victron docs confirm, their controllers shut down or fault <1v from rating (like a 99.xV "high voltage" lockout requiring a power cycle). Graciously, I’ll hope this sensitivity stems from their MPPT algorithm prioritizing precision over forgiveness, unlike MidNite's 150V-162V HyperVOC non-op / standby buffer or Epever's simpler 150V cutoff. Everything’s a trade-off. Victron's fast tracking come with less headroom, might benefit my setup though.
For my setup at 71.4V Voc (3S) or 23.8V (parallel), in theory, the 75v models work but their programming implies I should step up to 100v in case panels are -20°C. I won't trip it probably, and might connect a portable panel (likely only in parallel) sometimes, but it's a quirk to note despite this possibly being the best choice.
Epever PWM Concern
PWM Mode: Seems their stuff, including the 4215BN, drops to PWM at low PV-to-battery voltage delta (e.g. 19.6V to 15V in 4s charging scenario)-less efficient (130W vs. 160W MPPT) in my scenario under some conditions. Kinda wastes potential of those beefy connections they’ve got. "Stuck" reports are real-design flaw, manual reset via MT50/serial is PITA. Linux scripting might help, but it's a hassle. Manufacturer reps claim it’s intentional, won’t fix. Meh.
MidNite has more headroom for adding or replacing panels in future — panels don’t last forever. I also don’t fully understand their timer load features, yet I like the idea of not wasting idle draw (theirs is pretty low, think <.25w, maybe tad higher than EPEVER) — load timers are useful work, consolidating to one box, but not critical here. The bulk allows for a nice interface too, so factoring that in to size / weight.
Anyway, despite their defects and differing yet poorly documented design intents, I like these (and other) controllers — from afar. Any updated real-world experiences to break the tie? For instance, did EPEVER ever get their firmware more customizable or easier to program or Victron stop pretending protocol obscurity provides security?
Edit: I love the idea of an inverter-charger baked in, I’ll add AC battery charging soon anyway, but the trade offs for what I’ve found are unbearable in this application. Details at your leisure!
Epever 4215BN <$80
Victron 100/30 <$90
MidNite MNKID-B <$160
Panels are often in partial shade, under cloudy skies, and cold (vehicle mounted 3x 80w CIGS).
Victron proprietary Bluetooth coms for similar prices, sometimes lags, flimsy and puny connections for my nominally 10awg wiring (5.2mm2 stranded). User reports here and elsewhere, plus Victron docs confirm, their controllers shut down or fault <1v from rating (like a 99.xV "high voltage" lockout requiring a power cycle). Graciously, I’ll hope this sensitivity stems from their MPPT algorithm prioritizing precision over forgiveness, unlike MidNite's 150V-162V HyperVOC non-op / standby buffer or Epever's simpler 150V cutoff. Everything’s a trade-off. Victron's fast tracking come with less headroom, might benefit my setup though.
For my setup at 71.4V Voc (3S) or 23.8V (parallel), in theory, the 75v models work but their programming implies I should step up to 100v in case panels are -20°C. I won't trip it probably, and might connect a portable panel (likely only in parallel) sometimes, but it's a quirk to note despite this possibly being the best choice.
Epever PWM Concern
PWM Mode: Seems their stuff, including the 4215BN, drops to PWM at low PV-to-battery voltage delta (e.g. 19.6V to 15V in 4s charging scenario)-less efficient (130W vs. 160W MPPT) in my scenario under some conditions. Kinda wastes potential of those beefy connections they’ve got. "Stuck" reports are real-design flaw, manual reset via MT50/serial is PITA. Linux scripting might help, but it's a hassle. Manufacturer reps claim it’s intentional, won’t fix. Meh.
MidNite has more headroom for adding or replacing panels in future — panels don’t last forever. I also don’t fully understand their timer load features, yet I like the idea of not wasting idle draw (theirs is pretty low, think <.25w, maybe tad higher than EPEVER) — load timers are useful work, consolidating to one box, but not critical here. The bulk allows for a nice interface too, so factoring that in to size / weight.
Anyway, despite their defects and differing yet poorly documented design intents, I like these (and other) controllers — from afar. Any updated real-world experiences to break the tie? For instance, did EPEVER ever get their firmware more customizable or easier to program or Victron stop pretending protocol obscurity provides security?
Edit: I love the idea of an inverter-charger baked in, I’ll add AC battery charging soon anyway, but the trade offs for what I’ve found are unbearable in this application. Details at your leisure!
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