question

cstenger avatar image

How to switch off the MPPT with ignition on

Currently I have my 75/10 MPPT and Orion 12/12-30 wired up in parallel to the battery, which is totally fine. But I recognized that with alternating Solar input whilst driving (shaded by trees, bridges etc.) the voltage is jumping and when starting the car after the engine was off and the MPPT took over, it takes a while for the Orion to realized it should start working. Sometimes it doesn't even put out any voltage/current until the solar panels were shaded for a longer period of time.

I want to avoid this by switching off the MPPT when the ignition is on.

How can I manage this, what cables and components do I need?

MPPT - Solar Charge Controllerorion-tr smart
2 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

1 Answer
pau1phi11ips avatar image
pau1phi11ips answered ·

Just use a relay powered by the ignition on to break the remote contact on the MPPT.

3 comments
2 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

I'd like not to use a relay, at least no mechanical. Do you know a MOSFET relay with an NC contact?

cstenger avatar image cstenger Matthias Lange - DE ♦ ·

But: I would like to switch the MPPT off with ignition on. From the examplary applications shown with the inverting cable it seems it switches an inverter on (red and black contact closed) when load output is on.


I need it the other way round: ignition (cable input) ON, cable output OFF (open contact)


My interpretation of the non-inverting VE cable is, it pulls up the RX pin to +5V. I'd need pull down of the RX pin to GND. As I do have Micro JST PH 2.0 connectors here, I could use the regular non-inverting cable to DIY a cable myself, right?

Or buy the non-inverting VE cable and interchange pins: +5V to GND (hoping that the circuit under the shrink tube doesn't need the +5V to work, which I'm afraid it does).