Complete Magnum 48V Off-Grid System – (2) MS-PAE 4448 Inverters + AGS + Router – Fully Working

Interesting setup — Magnum doesn't get much love over here in the UK since it's predominantly a North American brand, but those MS-PAE units are genuinely solid bits of kit. The stacked 48V configuration giving you effectively 8.8kW of continuous output is no joke, particularly if you're running anything with a hefty startup surge.

Couple of things I'd want to know about a setup like this:

• What's the battery bank? AGS suggests it's probably paired with a generator rather than a pure solar arrangement — curious whether it's running AGM or lithium
• The router inclusion — is that the Magnum ME-RTR? If so, worth noting that the monitoring software is fairly dated compared to what Victron offer with VRM, but it does the job
• Transfer switch capacity — the PAE series handles 60A AC input if I recall correctly, which is decent for generator integration

My own setup is Victron-based (Multiplus-II 48V 5000VA) on a static caravan, so a completely different scale, but I've always been curious how Magnum compares in real-world use. The inverter efficiency curves on the Magnums are reportedly very good at partial loads, which matters enormously when you're running overnight on batteries.

Anyone else on here actually running Magnum equipment in the UK? Parts and firmware support could be a pain given the lack of local distributors — that'd be my main hesitation if I were considering picking up a system like this secondhand.

What's the asking price looking like?

@BayJason you're right that Magnum is a rare sight over here — most people go straight to Victron without even considering the alternatives. The MS-PAE series does have a decent reputation for robustness in the North American RV and off-grid scene though.

My concern with picking up something like this secondhand would be firmware support and sourcing replacement parts — Victron's UK distributor network makes that side of things straightforward, whereas with Magnum you're potentially looking at grey imports or waiting on shipments from the States.

For a shepherd's hut or cabin build where you want something you can just trust long-term, that parts availability question matters quite a bit. What's the asking price? Might still make sense depending on condition and age of the units.

Magnum's like that one American cousin who's actually competent but nobody invites to the party because Victron brought nicer brochures.

@TID_Electric that's a fair analogy honestly.

Curious about the practical side of running stacked inverters — does the AGS (auto generator start) on this system respond well to multi-inverter loads, or does it struggle to determine the correct trigger threshold when both units are pulling simultaneously? I've got a single Victron Multiplus-II on my static caravan and the AGS logic took some tuning to get right even on a simple setup.

Also wondering about spare parts availability in the UK if something goes wrong with a Magnum unit — that's always my hesitation with North American brands. Victron's dealer network here is fairly solid, but who do you go to for a Magnum repair or replacement board?

@RetiredEngineer61 stacked inverter setups are genuinely interesting to run — the two units split the load across phases, so each inverter handles one leg. The AGS (Auto Generator Start) module is the bit that makes it practical for off-grid use; it'll fire the genny automatically based on SOC thresholds or voltage drop rather than you babysitting it.

The main gotcha with stacked Magnums is that the communication cable between units is absolutely critical — lose that connection and you're back to single-phase only, which on a 48V PAE system at 4400W per unit means you've halved your available capacity overnight. Worth having a spare comms cable physically taped to the units.

On narrowboats specifically, the vibration environment can work those connectors loose over time. Victron's parallel/three-phase setup uses similar inter-unit comms and has the same vulnerability honestly.