I have used several different types of battery on both my bike trailer powering the amplifier and also my pedestrian...
https://www.youtube.com/watch?v=EzmKOMPegII QRP tests between Dave,VK2BSY and G4AKC/Pedestrian Mobile on 20M long-path early morning UK time.
I have been using the MFJ-1979 on my bicycle, back-pack and pedestrian mobile set up's for over 5 years and...