Thanks all for your replies 
The intention of the second battery was to split charge it, so I flattened the extra one with the extra load, but still had the original starting and running the vehicle. Slightly different from the norm as the extra load is there mostly mobile, not just parked up.
Hence the engine is mostly being driven with the load, so no need for a hand throttle.
Anyway, I have given up on the second battery idea, just nowhere simple to place it, but now have the digital voltmeter on the dash. We have a night event week Friday, will see how I get on then, now I will be able to see the state of the battery.
The intention of the second battery was to split charge it, so I flattened the extra one with the extra load, but still had the original starting and running the vehicle. Slightly different from the norm as the extra load is there mostly mobile, not just parked up.
Hence the engine is mostly being driven with the load, so no need for a hand throttle.
Anyway, I have given up on the second battery idea, just nowhere simple to place it, but now have the digital voltmeter on the dash. We have a night event week Friday, will see how I get on then, now I will be able to see the state of the battery.
