You could thread a piece of test lead wire with two probes through the current clamp if breaking the circuit is not an issue. Typically clamps are used for these kinds of currents. There are some smaller clamps. If you break the circuit, either with a shunt or a loop of wire, don't forget about fusing. Connecting a short across the battery terminals could result in some serious fireworks. You'll need to use a heavier wire gauge, typical test leads are not designed for 30A.