Agm accu overladen door Blue smart 12/30 230 lader

Interesting timing on this thread — something similar happened to me last winter at my cabin setup.

I've got a Victron AGM Super Cycle 170Ah paired with a Blue Smart IP22 12/30, and after leaving it on mains hook-up overnight during a particularly cold spell, the battery was noticeably warm come morning. Not dangerously so, but enough to make me investigate.

Turned out the issue was the temperature compensation. The Blue Smart chargers do support it, but only if you've got the optional Smart Battery Sense or a BMV with temperature sensor connected via VE.Network. Without that, the charger is essentially guessing — and in cold conditions it'll push higher absorption voltages than the battery actually needs, which can stress an AGM.

A few things worth checking in your situation:

• Is the charger profile set correctly? In VictronConnect, make sure you're on the AGM Spiral Cell or appropriate AGM preset — not a generic profile
• Is temperature sensing active? Without it, you're flying blind on voltage compensation
• What was the absorption time? If the battery was already reasonably full, a long absorption phase at elevated voltage is where the heat builds up

AGMs are less forgiving than lithium when it comes to overcharge — they can gas internally and you'll never know until capacity starts dropping off.

Have others here had similar experiences with Victron's mains chargers in colder climates? I'm wondering whether the Smart Battery Sense is genuinely worth adding, or whether a full BMV-712 install is the better route for proper monitoring.

@TransitAdventure worth checking what absorption voltage the IP22 is set to — Victron's default AGM profile runs at 14.7V which is fine, but if someone's accidentally selected the AGM Spiral Cell preset it jumps to 14.9V, which over a long unattended charge can stress the battery.

On my boat I use the Battery Safe mode with a proper temperature sensor dongle — makes a noticeable difference in winter when the bilge gets cold and the charger would otherwise push too hard.

Also, are you monitoring via the VictronConnect app? You can pull up historical charge logs and see exactly what voltage peaks it hit. That'd tell you pretty quickly whether it's a settings issue or a duff charger.

@TransitAdventure that's a worry, especially leaving it unattended at a cabin over winter. One thing worth checking beyond what @DevonBoater mentioned — have you looked at your battery temperature when charging? The IP22 doesn't have a built-in temperature sensor, so if your cabin gets cold the charger won't compensate, and ironically you can still see voltage issues even at lower temps if the battery's already been stressed.

Also worth connecting the battery to VictronConnect and checking the stored data — the app logs charge cycles and you can often spot if absorption has been running excessively long. If the AGM Super Cycle is regularly hitting float with high current still flowing, that's a red flag. Might be worth dropping absorption voltage slightly to 14.4V as a precaution.

@TransitAdventure this hits close to home — I've got a similar setup on my shepherd's hut and the thought of coming back to a cooked battery after a cold winter is genuinely grim 😅

Quick one: did you have any temperature compensation set up? The IP22 12/30 supports a temp sensor add-on, and in winter conditions a cold battery will happily accept higher voltages than it should without kicking back. Worth checking if the charger was compensating up when it should've been pulling back.

Also — what firmware version is the IP22 running? There were some quirks in older versions with AGM absorption timing that Victron quietly sorted. Easy to update via the VictronConnect app if you haven't already.

Had this exact scare on my boat last year. The IP22 is solid kit but the default AGM profile will push hard if your battery's already warm or the sensor's not connected.

Worth grabbing the temp sensor dongle if you haven't — makes a real difference once ambient drops and then climbs again through the day. Also check your storage voltage setting in the VictronConnect app; dropping it to around 13.2V for long unattended periods saved me a lot of worry.

@TransitAdventure for a cabin setup I'd honestly consider enabling the "Storage" mode rather than leaving it on a full cycle programme indefinitely.