# BMV relay not working, how to protect it?

**URL:** <https://community.victronenergy.com/t/bmv-relay-not-working-how-to-protect-it/52487>\
**Category:** Q&A and troubleshooting\
**Tags:** bmv, parallel, marine, diy\
**Created:** [30 January 2026 01:03 UTC](https://community.victronenergy.com/t/bmv-relay-not-working-how-to-protect-it/52487 "2026-01-30T01:03:37Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![CombatDiver](https://avatars.discourse-cdn.com/v4/letter/c/65b543/32.png) [@CombatDiver](https://community.victronenergy.com/u/CombatDiver)\
**Post date:** [30 January 2026 01:03 UTC](https://community.victronenergy.com/t/bmv-relay-not-working-how-to-protect-it/52487/1 "2026-01-30T01:03:37Z")

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Hi

I used the relay of the BMV to drive a circuit, when V is more than 13.6 then relay ON, and with this I swtich 12v to the L of a Relay, how is going to drive the L of the big relay connecting service, crank and bow batteries, to keep them at 13.7 during the day

After few years, my solution stop working. The relay now is not working, no enough to drive the L of the external relay. It is a fact that the problem is the relay inside the BMV

My question is , how can I do it to prevent again to broken the relay? Withdraw currrent of the relay could not be reached the 1A limit

Im going to put the clasical PNP txtor, drived by the base with an R by the out of the relay connected to 12v. Also use a Diode parallel to the L

Any advice or tip , better than this solution ?

Is this relay a solid state relay ( silicom) or a real relay?

BTW. I dont want to use the cyrics relay solutions, because I cant control them and besides for certain current, they are too expensive

Thanks

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**Author:** ![CombatDiver](https://avatars.discourse-cdn.com/v4/letter/c/65b543/32.png) [@CombatDiver](https://community.victronenergy.com/u/CombatDiver)\
**Post date:** [30 January 2026 01:13 UTC](https://community.victronenergy.com/t/bmv-relay-not-working-how-to-protect-it/52487/2 "2026-01-30T01:13:59Z")

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Hi again

I saw this

> [@Using inverter / MPPT / GX device programmable relays with higher current, inductive or capacitive loads](https://community.victronenergy.com/t/using-inverter-mppt-gx-device-programmable-relays-with-higher-current-inductive-or-capacitive-loads/99):
>
> Many Victron products have programmable relays included which can be used to send signals between each other or to control small loads. These ae typically rated as for the Cerbo GX as DC up to 30 VDC: 6 A DC up to 70 VDC: 1 A AC: 125 VAC: 6 A There have been many reports within the community from people who have burnt out the contacts or welded the contacts closed in the programmable relays in their systems. This is often caused by connecting the relays to inappropriate loads, sometimes loa…

Can I use the flyback diode is also known as a snubbing diode without the NPN?

Thanks a lot

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**Author:** ![chrigu](https://avatars.discourse-cdn.com/v4/letter/c/ba9def/32.png) [@chrigu](https://community.victronenergy.com/u/chrigu)\
**Post date:** [30 January 2026 05:41 UTC](https://community.victronenergy.com/t/bmv-relay-not-working-how-to-protect-it/52487/3 "2026-01-30T05:41:18Z")

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You should always use a flyback diode when switching a coil, no matter if the switching is done by a physical relay contact or a transistor