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

Interesting listing — the MS-PAE 4448 is a solid bit of kit, and running two in parallel gives you a genuinely capable system. Magnum has always had a decent reputation in the marine and off-grid world, though you don't see them as commonly here in the UK as you do Victron. Parts and firmware support can get a bit murky this side of the Atlantic, which is worth factoring in if you're considering picking something like this up.

That said, 48V AGS integration is a real advantage if you're running a generator as backup — something I've had to think carefully about on my narrowboat setup. The automatic generator start based on SOC thresholds alone saves a lot of grief.

A few things I'd want to know before getting excited:

• What AGS model is included? The ME-AGS-N and ME-AGS-S have quite different capability sets.
• What's the battery bank it's been paired with? AGM, lithium? Has the inverter firmware been updated to handle LiFePO4 charge profiles properly?
• Hours on the units? Inverter-chargers at this power level can accumulate serious runtime.

The router inclusion is a bit of an oddity — presumably the Magnum ME-RTR for system monitoring and remote panel comms? If so, useful, but not exactly a selling point on its own.

For anyone with a larger off-grid setup or a liveaboard boat wanting serious AC capacity without going full Victron Quattro territory, this sort of system is worth a proper look. Would be curious what others think about Magnum's longevity compared to Victron MultiPlus in real-world UK conditions.

Great spot @DefenderAdventure. The MS-PAE series has proper surge capacity too, which matters if you're running motor loads like pumps or a compressor. Two of those in parallel gives you 8.8kW continuous which is genuinely impressive for a second-hand system.

Worth checking the AGS configuration before buying though — make sure whoever set it up hasn't got it doing something daft with the generator start thresholds. They can be a faff to reprogramme if you're not familiar with the Magnum Remote.

Anyone know what battery bank this was paired with originally? The 48V setup gives you flexibility, but I'd want to know the charge profile history before committing serious money. Lead acid treated poorly can look fine on the surface and then let you down badly within a season.

What sort of asking price are we looking at?

Worth noting that the MS-PAE 4448 runs on 48V nominal, so whoever picks this up needs a properly sized battery bank to match. At 4.4kW per unit you're looking at serious continuous draw capability — two in parallel and you've got headroom for most domestic loads including induction hobs.

My concern with any secondhand Magnum stack is the AGS configuration — if it's been set up around a specific generator, you'll need to remap those thresholds entirely. The Router unit being included is handy for the parallel comms, but verify the firmware versions match across both inverters before assuming it'll just work out of the box.

Also worth checking whether the DC wiring between inverters has been done correctly — Magnum are quite specific about cable length and gauge matching when paralleling, and a botched installation can cause load-sharing imbalance.

@SuffolkCruiser raises a fair point about the battery bank — I learned that lesson the hard way a few winters back when my backup system couldn't handle the draw during a prolonged outage and the voltage sagged badly.

What I'd be looking into with a setup like this is the AGS integration. Having automatic generator start baked in is genuinely useful for emergency backup scenarios — mine kicks the genny on at 20% SOC without me lifting a finger, which during the ice storm of 2022 was an absolute lifesaver.

The routing hardware bundled in is an interesting touch too. Magnum's network monitoring isn't the flashiest interface, but it's reliable and you can actually trust it when things go sideways at 2am. For a turnkey emergency system, that matters considerably more than pretty graphs.

@Frank1969 curious what your setup was when that happened — AGM or flooded?

For anyone considering this for a van conversion, worth flagging that the MS-PAE 4448 isn't exactly compact. Two of them plus the AGS module takes up serious wall space. I had to completely rethink my battery compartment layout when I was speccing a similar inverter arrangement.

That said, for a static off-grid install this is a cracking bundle. The Magnum router integration means you get proper system comms rather than bodging separate monitoring — something Victron does well with their ecosystem but Magnum handles differently.

At 48V you'd want to be thinking minimum 200Ah to get any real performance out of it, ideally 400Ah+. Fogstar or a quality lithium bank would pair nicely here.

@Frank1969 and @RussGreen — the battery chemistry question is worth exploring, but I'd also flag the AGS unit here as a significant consideration. On my narrowboat I run a Victron Multiplus-II and the automatic generator start functionality is genuinely what keeps the system reliable through winter months when solar is poor.

With a Magnum AGS paired to those two inverters, you're getting proper load-based and voltage-based start triggers — that's not something to underestimate for an emergency backup role. The question is what generator you're planning to marry it to, because the AGS comms need to match.

For a UK buyer, spares and support for Magnum kit can be patchy compared to Victron's distribution network here. Something to weigh up before committing.