Spent the last couple of weeks getting the battery rack prepared to take the lithium batteries. First attempt bowed a lot due to only having flat steel bar to support the batteries. I had an idea this would happen, but it was much worse than I expected. I welded some angle to the underside of the flat bars and it is good and strong now.
Mounted everything up and loaded the batteries on. They were a good snug fit and needed "persuading" to get the last battery in. I have painted the rack and welded a couple more brackets on to hold it down as it was resting on them before and was causing a rattle when driving. Now to load the rack back in the car, bolt it down then make a load of connector strips from the copper bar I have. I also need to make the hold down straps to go across the top. I shall use some 25mm angle (5mm thick) to hold the batteries down. I had to get smaller section than the 40mm used on the rack so that it can run between the terminals without any possibility of touching and causing a short circuit anywhere. I shall also use the tie downs to carry some trunking to run wires for the battery monitoring system. Still loads to do.