# Negative AC output power, and false DC power, only when charging **URL:** \ **Category:** DIY\ **Tags:** multiplus-ii, vrm, diy\ **Created:** [2 October 2026 20:14 UTC](https://community.victronenergy.com/t/negative-ac-output-power-and-false-dc-power-only-when-charging/63473 "2026-10-02T20:14:40Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![mtnbrit](https://avatars.discourse-cdn.com/v4/letter/m/ce7236/32.png) [@mtnbrit](https://community.victronenergy.com/u/mtnbrit)\ **Post date:** [2 October 2026 20:14 UTC](https://community.victronenergy.com/t/negative-ac-output-power-and-false-dc-power-only-when-charging/63473/1 "2026-10-02T20:14:40Z")
Hi I notice when my MP2 is charging from shore power, the AC output chart shows negative power, and also the DC system (smartshunt) chart shows a spike of extra load that isn’t real, ie my DC loads dont change during this charging period, but it measures more like 200-250W instead of the normal 50W-60W. When charging stops, it goes back to normal. Could this be some kind of wiring error? ![image](https://europe1.discourse-cdn.com/victron/original/3X/a/1/a1a97ceaf8317ab19c4ec36e28654179ee11d86c.jpeg) ---
**Author:** ![lxonline](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/lxonline/32/25567_2.png) [@lxonline](https://community.victronenergy.com/u/lxonline)\ **Post date:** [3 October 2026 13:45 UTC](https://community.victronenergy.com/t/negative-ac-output-power-and-false-dc-power-only-when-charging/63473/2 "2026-10-03T13:45:05Z")
> [@Negative AC output when connected to shore power](https://community.victronenergy.com/t/negative-ac-output-when-connected-to-shore-power/6237): > > I have a Multiplus ii 12/3000/120-50. There is a transfer switch for shore power / generator. The Multiplus has been working flawlessly for about 6 months but suddenly with shore power plugged in the connect app is showing 0 watts ac input and negative output which seems to be the wattage being used to charge batteries. The app also shows it is in charger only mode but the ac system in coach is electrified. I’ve updated firmware but no change. ---
**Author:** ![mtnbrit](https://avatars.discourse-cdn.com/v4/letter/m/ce7236/32.png) [@mtnbrit](https://community.victronenergy.com/u/mtnbrit)\ **Post date:** [3 October 2026 15:46 UTC](https://community.victronenergy.com/t/negative-ac-output-power-and-false-dc-power-only-when-charging/63473/3 "2026-10-03T15:46:41Z")
My MP2 doesnt have the 3.5mm jack. Also I dont think this matches my scenario, the issue only happens during charging and includes the odd DC system load. ---
**Author:** ![lxonline](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/lxonline/32/25567_2.png) [@lxonline](https://community.victronenergy.com/u/lxonline)\ **Post date:** [3 October 2026 16:39 UTC](https://community.victronenergy.com/t/negative-ac-output-power-and-false-dc-power-only-when-charging/63473/4 "2026-10-03T16:39:02Z")
Are you using an external CT at all? ---
**Author:** ![mtnbrit](https://avatars.discourse-cdn.com/v4/letter/m/ce7236/32.png) [@mtnbrit](https://community.victronenergy.com/u/mtnbrit)\ **Post date:** [3 October 2026 21:20 UTC](https://community.victronenergy.com/t/negative-ac-output-power-and-false-dc-power-only-when-charging/63473/5 "2026-10-03T21:20:24Z")
No external CT. The jumper block is in place. ---
**Author:** ![mtnbrit](https://avatars.discourse-cdn.com/v4/letter/m/ce7236/32.png) [@mtnbrit](https://community.victronenergy.com/u/mtnbrit)\ **Post date:** [8 October 2026 00:29 UTC](https://community.victronenergy.com/t/negative-ac-output-power-and-false-dc-power-only-when-charging/63473/6 "2026-10-08T00:29:45Z")
Would love some further input on this issue if anyone has any ideas how the MPII could be reporting negative AC output power, but only while charging. Here are some screen grabs of dbus-spy readings taken while charging. Any other parameters I could be monitoring? ![image](https://europe1.discourse-cdn.com/victron/original/3X/2/9/29295ac8d1f7f0353e18eaa4ac94d79cce52b38c.jpeg) ![image](https://europe1.discourse-cdn.com/victron/original/3X/8/0/80284a35acff65e85bb066b47c55dda3fc135d01.jpeg)