Only a short or a high charge rate could cause a fire, providing a degree of common sense is applied it is perfectly safe to charge a battery in sittu.
The alternative to crockodile clips attached to the battery is a power socket fitted to the car (like the cigarette lighter socket) attach a trickle charger to the adaptor and you do not need to lift the bonnet.
Glyn
The alternative to crockodile clips attached to the battery is a power socket fitted to the car (like the cigarette lighter socket) attach a trickle charger to the adaptor and you do not need to lift the bonnet.
Glyn