That volt meter is backlit, but is not as bright as it looks in the photo. At present it is just connected via the cigarette lighter socket. At some point I'll wire it in permanently. It is large enough that I can read it clearly through the rear window, which turns out to be useful, as I can tell from the voltage roughly what the state of charge is (whether it is trickle charging or whether it is still bulk charging.)
You will notice the spare charged battery in the passenger foot well. I'll carry that around for a while yet, until I'm fully confident of how deeply I can discharge the main battery. The main battery is a 90Ah AGM battery by the way. It is heavy, and was the biggest I could fit in the existing battery tray. AGM batteries can be safely discharged and recharged by at least 50% daily without ill effect. The battery came with a no-quibble 4 year warranty. I was quite up-front with the seller about what I was going to do with the battery and he said, "Yup, that's a 4-year no-quibble warranty. If it fails within 4 years we'll collect the old one and give you a new one at no charge."
Eventually, I will run an extra cable through a grommet in the firewall in the passenger footwell and fit a mains socket there, so I can plug in a 1kw fan heater to run in parallel with the pre-heater to defrost windscreens on cold mornings.
