Blue smart ip 22 parallel

Been thinking about this setup a lot lately, after having a similar head-scratcher on my narrowboat last winter.

I've got a Victron Blue Smart IP22 (30A, 3-output) handling both my house bank and starter battery, and honestly the way people wire these up varies wildly depending on what else is in the system.

The bit that tripped me up initially was the battery selector switch. When you've got a manual selector in the circuit alongside a smart charger that expects to "see" both banks independently, things can get a bit murky. The IP22's multi-output is brilliant in theory — it prioritises the main bank and trickle-charges the secondary — but if your selector switch is configured to combine both batteries, you risk confusing the charge algorithm altogether.

What I ended up doing:

• House bank wired directly to output 1
• Starter on output 2
• Selector switch left in the "both" position only when running the engine, never when on shore power

That separation made a real difference. The charger could do its thing properly without me second-guessing it.

Anyone else running an IP22 on a boat with lead acid across multiple outputs? Particularly curious whether anyone's gone down the route of adding a battery-to-battery charger on top of this for the alternator side — feels like that might be the cleaner long-term solution rather than leaning on the selector at all.

Would love to know what setups others are running, especially if you've got a mix of starter and leisure banks.

@LisaKelly66 been down this exact rabbit hole with my van setup — the IP22 in parallel works but Victron themselves will tell you each charger needs its own dedicated battery connection (not daisy-chained) otherwise you're essentially playing "guess who's doing all the work" and spoiler: it's always the one nearest the battery 😅 — use the VE.Direct ports to sync them via VictronConnect so they negotiate charge states properly, otherwise you'll have one sat in absorption while the other's still hammering away in bulk like it didn't get the memo.

@LisaKelly66 funny you mention the narrowboat — I ran into something similar when I was setting up emergency backup for my shepherd's hut last year.

The bit that caught me out: even when two IP22s do sync properly, they're sharing the same algorithm assumptions about battery state. If your house bank and starter battery have different histories, one charger ends up fighting the other's conclusions.

What actually sorted it for me was treating each bank as entirely independent — separate charger, separate sense wires, no heroics. The IP22 3-output is genuinely brilliant for one bank with multiple outputs, but that's subtly different from what you're describing.

Worth jumping into VictronConnect and checking whether your units are actually seeing identical charge states before committing to the parallel route.

Had this exact debate when I was wiring up the motorhome last spring. The thing that settled it for me was just ringing Victron's UK distributor directly — got a straight answer in about ten minutes that saved me weeks of forum rabbit-holing.

What I'd add that nobody's mentioned yet: if you're running separate outputs to separate banks, the charge profiles matter as much as the current capacity. My setup has a lithium leisure bank and a separate AGM starter — the IP22's individual output programming was the actual feature I needed, not the parallel question at all.

Might be worth stepping back and asking whether parallel is genuinely solving your problem @LisaKelly66, or whether the 3-output version is already doing the job you're imagining two units would do.

@LisaKelly66 the bit nobody mentions about parallel IP22s is the firmware version mismatch — pair two units that shipped six months apart and they'll argue like siblings in the back of a Volvo. Victron Connect will show both charging, technically correct, practically a mess. Spent an embarrassing amount of time on this with my shepherd's hut emergency backup before realising one unit was on v3.26 and the other v3.31. Update both to identical firmware before you even think about load-sharing. The VE.Smart Networking also needs enabling on both simultaneously, not sequentially — the order matters more than the manual implies.

@Geordie ringing Victron support is solid advice, though you'll occasionally get wildly contradictory answers depending which day you call.