# MPPT for charging from truck? **URL:** \ **Category:** DIY\ **Tags:** beginner\ **Created:** [17 January 2025 04:17 UTC](https://community.victronenergy.com/t/mppt-for-charging-from-truck/18950 "2025-01-17T04:17:16Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Stephen](https://avatars.discourse-cdn.com/v4/letter/s/96bed5/32.png) [@Stephen](https://community.victronenergy.com/u/Stephen)\ **Post date:** [17 January 2025 04:17 UTC](https://community.victronenergy.com/t/mppt-for-charging-from-truck/18950/1 "2025-01-17T04:17:16Z")
I have a 24V truck and a house built inside a semi-trailer, the house is set-up on 24V 240AH AGM batteries. I have previously asked about adding solar to this but this concerns charging the house batteries from the truck alternator when driving, DC to DC. Am I able to use an MPPT to control the charging from the truck in the same way is it controls the charge from solar panels? If so, am I able to run both solar panels and the truck charging through the same MPPT? From what I can see, the alternator output is 24V, 40 or 50amp. Many thanks for your thoughts. ---
**Author:** ![pwfarnell](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/pwfarnell/32/2341_2.png) [@pwfarnell](https://community.victronenergy.com/u/pwfarnell)\ **Post date:** [17 January 2025 09:12 UTC](https://community.victronenergy.com/t/mppt-for-charging-from-truck/18950/2 "2025-01-17T09:12:15Z")
Is the alternator charging a 24V starter / engine / chassis battery. If so then you need to have a DC to DC charger such as a Victron Orion 24/24/17. [dc-converters/orion-tr-smart-non-isolated](https://dc-converters/orion-tr-smart-non-isolated) ---
**Author:** ![Stephen](https://avatars.discourse-cdn.com/v4/letter/s/96bed5/32.png) [@Stephen](https://community.victronenergy.com/u/Stephen)\ **Post date:** [17 January 2025 09:22 UTC](https://community.victronenergy.com/t/mppt-for-charging-from-truck/18950/3 "2025-01-17T09:22:26Z")
Yes, that is the case. Thanks for your help 🙂 ---
**Author:** ![Stephen](https://avatars.discourse-cdn.com/v4/letter/s/96bed5/32.png) [@Stephen](https://community.victronenergy.com/u/Stephen)\ **Post date:** [17 January 2025 14:50 UTC](https://community.victronenergy.com/t/mppt-for-charging-from-truck/18950/4 "2025-01-17T14:50:09Z")
Follow-up question. How do “isolated” and “non-isolated” converters differ? Oops, found this: This article answered my question. > **[Victron DC to DC Orion Chargers. Isolated or Non Isolated ? Which is right ?...](https://blog.voltaconsolar.com/2021/12/23/victron-dc-to-dc-orion-chargers-isolated-or-non-isolated-which-is-right/)** > > Victron Energy Orion-Tr Smart DC-DC Chargers The Victron Orion-Tr Smart DC-DC chargers are DC to DC adaptive 3-stage battery chargers. The “smart” units have a Bluetooth connection for faster and easier set up directly from a mobile phone. They are... I will need isolated, I think, because the truck and trailer are completely separate units. ---
**Author:** ![pwfarnell](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/pwfarnell/32/2341_2.png) [@pwfarnell](https://community.victronenergy.com/u/pwfarnell)\ **Post date:** [17 January 2025 15:16 UTC](https://community.victronenergy.com/t/mppt-for-charging-from-truck/18950/5 "2025-01-17T15:16:24Z")
On non-isolated the input and output negative connections are common inside the unit. The negative connection is then made to one of the batteries or chassis. The starter and domestic batteries need to have a common negative, either directly connected or both connected to the chassis. This is the route the charging current takes. The isolated version has independent negatives for input and output. Some vehicle builds keep the domestic negative separated from the chassis. In this case you need the isolated version. You can use an isolated version if the domestic is connected to the chassis, it is not usually done because they cost more. ---
**Author:** ![Stephen](https://avatars.discourse-cdn.com/v4/letter/s/96bed5/32.png) [@Stephen](https://community.victronenergy.com/u/Stephen)\ **Post date:** [17 January 2025 15:35 UTC](https://community.victronenergy.com/t/mppt-for-charging-from-truck/18950/6 "2025-01-17T15:35:29Z")
To the best of my knowledge the truck and trailer are completely separate units. The trailer is protected with its own RCD and the truck negative goes to the truck chassis. ---
**Author:** ![system](https://europe1.discourse-cdn.com/victron/original/1X/21a9a7b5db7c6339715f993568736a7053199995.png) [@system](https://community.victronenergy.com/u/system)\ **Post date:** [31 January 2025 15:36 UTC](https://community.victronenergy.com/t/mppt-for-charging-from-truck/18950/7 "2025-01-31T15:36:02Z")
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