Urgently need a mobile mechanic who can help

[Roxylass]

I have one of those red removable ones what type would you recommend Tony

[Tony Brooks]

34 minutes ago, Roxylass said:

I have one of those red removable ones what type would you recommend Tony

 

Something marketed by a proper marine supplier, like Blue Sea, Victron etc. Certainly nothing from Ebay/Amazon unless it is from a reputable UK supplier. In the very worst case a cheap master switch could cause a fire, but not likely on a start battery, far more likely on the domestic circuit feeding a large inverter.

[Kingdom Isambard Brunel]

I have used several of these     https://www.temu.com/uk/cut-off-power-kill-switch--killer--switches-12v-24v-1000amp-heavy-duty--tractor-battery-isolator-g-601099594402980.html?      and have never had a problem even with big inverters drawing many hundreds of amps.