Magnum MMS1012 PSW Inverter Upgrade and Lifeline AGM Batteries Replacement

 

Our 2011 RT Agile came with a Tripp Lite 750 watt inverter/charger from the factory. It works ok for the most part, but the built-in charger has limited charge parameter setting especially for AGM battery which we had.

The factory installed coach batteries (US Battery AGM2000) lasted us about 6 years, until it was “cooked” by the Tripp Lite charger during our recent summer roadtrip. I was able to temporarily replace it with a Walmart battery the following day, and that saved us the rest of the trip.

Right after the trip, I replaced the coach batteries with 2 Lifeline GPL-4CT batteries; I also replaced the inverter/ charger with Magnum MMS1012 1000 watt pure sinewave charger/inverter, a ME-ARC50 remote, and ME-BMK battery monitoring kit (clickable Amazon links). The Magnum ME-RC50 should work well with the MMS1012, I just got a really good deal with the ARC50 so I took that opportunity. I like the button layout or the ARC50 remote but some of its advance settings aren't compatible with the MMS1012.

The MMS1012 inverter/charger has a built-in 50 Amp PFC charger with battery temperature sensor. The charger can be adjusted to correct charging parameters recommended by Lifeline battery, everything is covered in it's manual.

I’ve been planning of replacing the Tripp Lite inverter to a higher output PSW inverter that would run a small microwave, so it's the perfect time to replace it. We use the microwave most of the time and hated the idea of running the propane genset just to use the MW for couple of minutes. I eventually replaced the MW and the 3-way Dometic fridge to AC/ DC compressor fridge, but that would be on my next post.

I run a dedicated 2/0 battery cables from the coach battery to the inverter, that means drilling a new hole into the flooring of the driver seat base. Roadtrek only run a (+) DC wire from the inverter to the coach battery, the (-) DC wire is grounded into the frame of the vehicle. The biggest challenge was the placement of the new Magnum inverter as it is much bigger in size compared to the stock Tripp Lite inverter.

NOTE: Before removing the driver seat and disconnecting the driver seat belt sensor, disconnect the chassis battery from the ground disconnect point located next to the gas pedal.

The new Lifeline AGM batteries (GPL-4CT 220Ah) with custom (+) battery busbar with acrylic cover and battery heat shield. The heat shield was made from aluminum sheet then faced with heat insulation mat.

Custom made (+) battery terminal busbar with clear protective cover.

Close-up shots of the DIY busbar. I use Blue Sea Systems terminal fuse/ fuse block (clickable Amazon links) for the inverter and generator (+) wire.

The busbar is made from pure copper flat bar then tinned, 3 stainless steel bolts were threaded from the bottom of the bar. The bolt heads were soldered into the copper bar to prevent them from unthreading. The bottom and side of the busbar is then encapsulated in a plastic resin for insulation and support. The clear cover is made from acrylic plastic.

The battery shunt shared by Magnum and Blue Sky solar controller. The Magnum BMK monitor is only added for my convenience so I can monitor the battery from the driver seat. The Blue Sky monitor I have can do the same battery monitoring.

Here is another shot angle of the batteries and wirings. I added another heat shield towards the front of the batteries (not pictured). I noticed that the radiator fan blows hot air towards the front of the batteries and the addition of the front shield has significantly blocks further heat transfer into the batteries.

I made a cardboard copy of the inverter and with careful measuring I was able to fit it inside the driver seat base using custom brackets. Magnum manual calls for 2 inches minimum space all around the inverter when it is enclosed. The inverter is mounted at a slight angle with front slightly lower than the back, it would not be ideal to mount it the other way around as the inverter internal fan is blowing from front to back.

Custom mounting brackets for the inverter.

The large aluminum MB module was relocated below the inverter. The black MB module on the bottom left of the picture above was slightly lowered using a fabricated aluminum bracket, this is done to create a slack to its wiring and prevent the wires from chaffing into the inverter brackets.

Close-up view of the DIY MB module bracket.

2/0 battery cables from coach batteries.

It was a tight fit into the seat base with only about an inch of space towards the front and right side of the inverter and about 1 to 1 ½ inch of space towards the rear, but there is enough space under the inverter where the air intake is located. I added 2 vent fans (one intake, one exhaust) into the air intake grill on top of the seat base. The vent fans are temperature controlled and kicks in on a set temp. I manage to salvage the temperature control switch from my old Fantastic Vent fan and used that to control the inverter vent fans.

Made a hole in front of the driver seat base to access the inverter circuit breakers in case it needs to be reset. The manual inverter power button can be reach from the rear opening of the seat base, although it is a tight fit for my small arm/hand. The remote control is all you need to control and configure the inverter, so access to the manual power button is not really needed.

Network wiring to the BMK, remote panel, and battery temperature sensor.

Plastic Velcro is used to mount the BMK unit under the driver side dashboard.

The Magnum remote panel, easy access and monitoring right from the driver seat.

Temperature controlled inverter vent fans. I use this PC fans from SilenX (EFX-09-15 Effizio), it has good airflow and quiet.

Custom inverter vent fan temperature switch. The temp switch was salvaged from an old Fantastic vent fan, I'm sure you can get this type of switch from Amazon. The temp switch is directly wired and fused from the battery solenoid (+) post located inside the driver seat base, the (-) is grounded to the chassis via same ground post used by the inverter.

We recently went to Death Valley and had a chance to test out the inverter. The vent fan works as expected. The 600 watt microwave works really well with the 1000 watt Magnum inverter; occasional use of MW for heating a cup of water or left over food is now a breeze.