I wouldn't want to make a battery!
I fear that it’s already a battery Dave.
Unlike the Ford donor cars that use the Duratec engines, I think our trads have a little extra 'electrochemical activity' occurring in the cooling system.
I’ve always had a thing about those large factory fitted stainless coolant tubes that runs across the top of the engine and also at the front. Why didn’t they use ali tubes... and it would have been cheaper too? Introducing stainless steel with an ali engine/rad is not great for longevity, the materials aren’t close on the nobility index, the ali bits are going to get eaten sooner. And any corrosion inhibitors in the coolant will have to work harder and probably degrade sooner too. We do see reports on here of aftermarket ali rads that have leaked after they have been installed for a few years.
Regarding the coolant, other than changing say once a year I’m not sure what else you can do to mitigate, even waterless can absorb water over time. I’m way too lazy to change the coolant that often so my latest harebrained plan is to incorporate a sacrificial zinc anode into the radiator plug at the next coolant change.
I do like the Focus tank, a good investment. I guess you could always add a dip stick to the cap to check the level. The plastic ones look so tatty after a year or so and you can’t clean them.
