Current Surge on Shore Power Trips Breaker

Ikanizer · October 2025

Maybe someone can explain this. I have a 2023 400 with 3 x Battleborn lithium batteries. I haven’t modified anything electrical except adding two batteries and a smart shunt. When batteries are not full and I plug in shore power I see a spike in current that sometimes trips the push button breaker with the yellow flipper next to the battery switch. I have had to reset that thing multiple times on occasion all the while wondering if I was risking burning something up. Does this breaker need to be bigger or is something else wrong.

Here is a screen shot of what happened recently when I plugged in after a couple months of no activity.

rfuss928 · October 2025

What is the current rating on the circuit breaker that is tripping?
You current is spiking well above 40 amps in the example provided. I think the 400's converter is rated at 55 amps output. It seems like the breaker (and maybe wiring) may be underrated for the application..

pthomas745 · October 2025

The newer 400's with the "4 battery lithium" setups all were updated to 50 amp breakers.

Ikanizer · October 2025

pthomas745 said:

The newer 400's with the "4 battery lithium" setups all were updated to 50 amp breakers.

Thanks. I think the 4 battery setup was an option on my 2023 model. So do you think it’s safe to assume a 50 amp breaker would solve my problem without risking anything?

Bill&Suze · October 2025

pthomas745 said:

The newer 400's with the "4 battery lithium" setups all were updated to 50 amp breakers.

@pthomas745, do you happen to know what the wire gauge is on the newer 400's, now that breakers were updated to 50? Is battery wiring perhaps heavier than earlier models? @Ikanizer's 2023 T@B may have lighter gauge wiring not suitable for a higher rated breaker.

pthomas745 · October 2025

There are threads that go into great detail on these installs and wire gauges, etc. This thread has an early look at the first trailers with the "4 lithium with Multiplus" factory installs in the 400. I just ran through this quickly again, and what I noted was the original "4 battery" setups had the 40 amp Gloso in a comment from early 2023. Another owner, in a comment from April, 2023, shows a 50 amp breaker. So, obviously, it seems that NuCamp learned something in that build process.https://tab-rv.vanillacommunity.com/discussion/16379/2023-400-with-the-400-ah-lithium-mod-victron-inverter/p1

There are examples of other owner's lithium upgrades, and discussions about wire gauges in that thread, also.

Current Surge on Shore Power Trips Breaker

Comments

Categories