Magnum 2812 Inverter/Charger...

I have the Freedom 20 (100 amp Charger with 2,000 watt inverter) and the Link 2000 battery monitor. I replaced my batteries this past March, swapping out 10 Trojan T-105's in the House bank with the identical batteries.

I am concerned that the link monitor is "loosing its way" with the number of amp hours consumed. When I am on AC, and float charge, the monitor indicates a slow battery usage of about 10 amp-hours per day. The system is on "float" charge. Battery voltages indicate to me that the system is charging properly and when I am off-grid, voltages seem consistent with the amps consumed. However, when I go back to charge, it seems the system returns to "accept" and float charge states prematurely, with a residual "negative" amp-hour reading. Because of these concerns I have been careful not to discharge the batteries by more than 250 amp hours (1125 total capacity) and I have been diligent with using the generator twice per day for an hour or two, even though its not the most efficient use of charging with the lower charge acceptance rate.

As the charging system and battery monitors are circa 1998, I'm thinking it is now time to upgrade the setup before the system fails. I met a long time KK 42 owner at the PNW "Krogin" this past week and he is very pleased with his Magnum 2812 Inverter/Charger and the Magnum Energy ERC50 control panel. Also, a brand new KK 44 was commissioned with a Magnum charger (not sure which one) and also the Magnum Energy ERC50 control panel. The control panel displays SOC as well as the usual voltages amp-hours etc.

When I go through this change, I will also reconfigure the cabling to the battery banks to ensure uniform charging across the units. I believe there are a couple of tweaks that can be done here based on recommendations from "Clectric" as well as a marine electrician who was quite helpful.


Thoughts from the group?

You need to get the Magnum Battery Monitor Kit (BMK) to go with it. Excellent gear, and will provide a more accurate ongoing measurement of state of charge than an amp hour meter.

One thing I noticed when I switched my inverter bank to Trojans (4 L16's in my case), it took them a while to "break in". It wasn't until I double checked state of charge with a hydrometer, and consulted with the helpful folks at Trojan that I understood that all was well. This is also covered in their User Manual available here:

http://www.trojanbattery.com/pdf/TRJN0109_UsersGuide.pdf

Thanks George. Yes, I have factored in the Magnum BMK kit into the setup as well. I guess that package includes the "shunt" as well.

Part of this work will be to re-cable the alternator to the house bank buss bar and to ensure that the two boxes of batteries are equally charged, something that needs to be reconfigured from the current setup.

The son of a friend of mine has just completed his marine electricians apprenticeship with a full service marine yard. He has been most helpful and has essentially confirmed what Celectric had already pointed out to me.

Jim

George: I read the link you provided (I had read through a different manual I believe) and I noticed the comment about the break in period of 50-100 cycles. Interesting! Also, I have seen "Table 7" before and I have used that as a guide to confirm SOC, to the extent that can be determined from voltages from a system under active use. I've been perhaps too paranoid about over discharge. Hopefully there aren't issues with charging too soon!

Jim

Two years ago we installed the Magnum 2800 PSW inverter charger, remotes and BMK you are contemplating. Flawless. Also added BMK for engine start batteries.

Took out a Freedom 3000 MSW unit and Link 2000 which were working OK but some issues had arisen with NMEA 2000 and other electrical gear that need a PSW unit.

I have a MagnaSine 2812 in the Californian 45MY I bought a few months ago to live on. The PO installed it in 2009 along with the BMK and the ERC. All my previous inverter experience has been with the old Xantrex mod sine wave Freedom units and with dual Victron Multiplus units (don't EVEN get me started on those!) However the Magnum seemed like a nice unit. Unfortunately, my engine guy left a hose clamp loose after cleaning the heat exchangers and the first time I used the boat (350-mile trip to South Florida), saltwater sprayed all over the inverter. I checked on the engine room just in time to see the MagnaSine releasing some of its magic smoke.

$922 later, it seems to be fixed and working very well.

I'm still reviewing the options here. The current IC is the Freedom 20, which is probably 15 years old. It's a 100 amp charger and 2000 watts on the inverter. Originally I had thought that the Magnum 2812 would be the correct choice with 125 charge and 2800 inverter. However we are mostly a DC boat and presently we leave the inverter "off" unless needed. We don't have home entertainment systems and the fridge and freezer are DC units. We run the coffee mill for perhaps 1 minute a day and some halogen lights some days for at most a couple of hours due in summer evenings, more in the winter but then we are usually on he horse power. The microwave is not currently wired to the inverter circuit, but that is an option. We only use that occasionally. So, why not consider the Magnum 2012 with 100 amps charge and 2000 watt inverter? I do like the additional 25 amps of charge to challenge the generator more, but there are likely some greater wiring requirements for the 2812. Note that I do have to shorten the length of the DC cabling.

Thoughts?


Jim
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Have the Magnum 3112 with remote panel and have been extremely happy with it as an inverter and a battery charger.

Ted