# When does the trickle charger work? **URL:** \ **Category:** DIY\ **Tags:** trickle-charger, multiplus\ **Created:** [28 February 2026 12:54 UTC](https://community.victronenergy.com/t/when-does-the-trickle-charger-work/54126 "2026-02-28T12:54:24Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![sanderdrupal](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/sanderdrupal/32/47047_2.png) [@sanderdrupal](https://community.victronenergy.com/u/sanderdrupal)\ **Post date:** [28 February 2026 12:54 UTC](https://community.victronenergy.com/t/when-does-the-trickle-charger-work/54126/1 "2026-02-28T12:54:24Z")
Hello, I have a Victron Multiplus 12/1200/50 and I want to use the trickle charger function for my car battery. I wired everything up, following the forum post about the trickle charger ( [How does the Multiplus trickle charger work](https://community.victronenergy.com/t/how-does-the-multiplus-trickle-charger-work/98) ). Leisure and starter battery share a common ground: Leisure battery is connected to smart shunt, and smart shunt is immediately connected to busbar, where there is a cable going to chassis ground of car. Car battery is connected to chassis ground. I’ve measured the current draw on the positive cable from the multiplus trickle charger to the started battery, but there is no current flowing. My started battery is 12.10V and my leisure battery 13.6V. Should the trickle charger always work? Even when the inverted is switched off? Or has the isolated DC-DC converter something to do with it? My schematic is below. You can see the red wire from the multiplus, called “trickle charger”, going to a positive connection point of the starter battery. Thanks! KR Sander ![CamperElectrics](https://europe1.discourse-cdn.com/victron/original/3X/2/c/2c4a681aa220ca75a5a0783d17c8dbfba47bd2fc.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:** [28 February 2026 13:34 UTC](https://community.victronenergy.com/t/when-does-the-trickle-charger-work/54126/2 "2026-02-28T13:34:58Z")
It needs both the positive and the negative connected to the starter battery to complete the circuit. Current cannot flow otherwise. > [@How does the Multiplus trickle charger work](https://community.victronenergy.com/t/how-does-the-multiplus-trickle-charger-work/98/1): > > When the domestic battery voltage reaches 13.2V the starter battery voltage starts to increase (0.3V drop due to the diode). The trickle charger follows the internal battery charge algorithm but trails a small volt drop behind the house battery. ---
**Author:** ![sanderdrupal](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/sanderdrupal/32/47047_2.png) [@sanderdrupal](https://community.victronenergy.com/u/sanderdrupal)\ **Post date:** [28 February 2026 14:18 UTC](https://community.victronenergy.com/t/when-does-the-trickle-charger-work/54126/3 "2026-02-28T14:18:26Z")
My positive wire is connected straight to the starter battery (only a fuse is between it). The negative of the starter battery is connected to the chassis ground I assume. My leisure battery and all other negatives are also connected to the chassis ground. Or do I have to run a seperate negative cable from shunt load side to my starter battery minus? Thanks ---
**Author:** ![chrigu](https://avatars.discourse-cdn.com/v4/letter/c/ba9def/32.png) [@chrigu](https://community.victronenergy.com/u/chrigu)\ **Post date:** [28 February 2026 15:10 UTC](https://community.victronenergy.com/t/when-does-the-trickle-charger-work/54126/4 "2026-02-28T15:10:03Z")
> [@sanderdrupal](#): > > Should the trickle charger always work? Even when the inverted is switched off? Yes, since its a simple diode and current limiter. As long as theres a high enough voltage on the MPs positive terminal then the starter battery should receive a charge. I would also expect the 1.5V to be enough for a current to flow. How does it behave when the leisure battery is being charged? ---
**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:** [1 March 2026 04:52 UTC](https://community.victronenergy.com/t/when-does-the-trickle-charger-work/54126/5 "2026-03-01T04:52:58Z")
Because of voltage drop it may work better if it has a dedicated wire.