Solar pannel trickle battery charger

[andys15]

I've just bought a solar powered trickle battery charger today. anyone else have tried one of these or has got one of these, how well do they work etc, any pros and cons with them, anything i should know about before installing one, only major thing i can thing of which will be a pain will be disconnecting it each time i want to start the car to rule out getting any spikes from the battery back to the pannel, but it already has a built in diode hopefuly pretecting back charge, but will wait and see and test it out to see what fuses blow etc, any ideas welcome, thanks