Hi Julian

> There isnt a whole load of difference in the price of the SLA batteries as
> you increase Ah (at least to a point), just they get heavier. Depending on
> your situation, if you decide to use the SLA type, you may like to get
> larger ones, for future possibilities too

I have to carry this system with a ribbon over my shoulder for two hours
and around 6-8 kilometers, so "just they get heavier" is definitely a
matter for me ;-)

Do you connect the batteries direct to the -/+12V lines or do you feed
them into the voltage stabilizers (7812/7912) in the power supply

Florian