has been running with a Magnum Energy MS2812 sine wave inverter/charger since last June, and we've been living aboard
since last July, and cruising full time since September. July/August/early September we were dockside, as was most of November and a couple weeks in December (due to an accident
- hit by another boat while at the fuel
dock!). All the rest has been at anchor
, depending on our genset (Westerbeke 7.6 kw diesel) and to a lesser extent an Air Breeze wind generator
. So what follows is not really six months of on-the-hook experience.
Our power requirements are fairly high right now, as my wife works full time - and a laptop
actually draws a bit of juice over time.
So, for now, the MS2812 is working great - while charging
it actually puts out 130A rather than the rated 125A. I have three minor complaints, though:
- While idling in invert mode, it draws ~ 5-7 amps with no AC loads other than an idle microwave (built-in clock) and a clock/radio. It does have a "power search" mode where it will put out AC power in a short burst and monitor if there are any active loads. You can set the threshold at as little as 5W. For us, it's not as great as it seems because of those pesky clocks. If I were to unplug the clock radio and the microwave, the feature would be useful to us.
- I wanted to team the MS2812 with an Iota Engineering DLS-75/IQ4 75A charger in order to blast our 800 amp-hour AGM house bank with 200 amps to cut down bulk charging times, but right now, they don't play very well together. They work ok when on shore power - but that's not when I need that kind of charging capacity. When running both off the genset, if I turn on the breaker for the Iota charger, the Magnum will shut down charging. It used to be worse - before I corrected the wiring done by an ABYC/licensed marine electrician who didn't quite follow my wiring plans, the Magnum would actually go into invert mode, and then shut down. It made it look like there was an AC overload condition, but the Iota charger is on another service leg (the genset is 120/240V split phase). Only when the Iota was turned off would it go back to AC pass-thru mode and begin charging.
- There is quite a bit of RF hash - enough to break squelch on a VHF handheld if it's within 10-12 of the unit. Since I haven't had time to finish the ham and SSB radio installs, I've been ignoring that one (other higher priority boat projects!).
Just today I fixed another minor problem with the Magnum install - the electrician mounted the temperature sensor to the positive battery post on the end of the bank rather than a negative post in the center of the bank. There's a possibility that having 12 volts on that thermistor lead may have been contributing to the dual charging problem - I'll know tomorrow when I charge again!
Another minor problem was that the original and a replacement remote
display died (the original was DOA as shipped), and the controller board in the main unit (manufactured in 3Q07) had an older firmware revision, so I had to send that back to the factory to be updated...
All in all, having dealt with electronics
for over 25 years, the infant mortality rate was higher than expected, but Magnum stood by their warranty. And their tech support is pretty good. They're waiting on me to get back with them regarding the results of their advice on the charging problem.
Don't get me wrong - the Magnum is nice, especially for the price
. I chalk it all up to teething problems.
I looked at the Victron models, but at the time the exchange rate made them prohibitively expensive - the Quattro was more than $4000 USD!
For me, the nice feature is the Magnum's ability to pass through two independent 30 amp service
circuits, but I wish they'd have two AC neutral inputs/outputs rather than one. ABYC recommendations call for boats with multiple shorepower inlets to maintain separate neutrals throughout the boat and all the way back to the shorepower pedestal
. The Magnum doesn't adhere to that...
Finally, Magnum seems to believe in openness, rather than keeping their protocols all locked up like some software
vendors up in there neighborhood in Washington
. They publish their networking protocol, and I'm investigating how much work it would take to write a little translation program so I can have my PC relay the inverter
information out an NMEA