I have since made a few other changes. I had the local emergency exit lighting maintenance contractor come around the office servicing their DC power packs. A few had packs with a battery string that had failed. I asked for the dead battery packs, with the deal that I would pay him the scrap lead value of any I kept. Well, I don't need 24V, and found that in most the failure was down to infant failure of a single battery in the string. So I brought my battery conditioner/charger in and charged up pairs in 12V configurations to see which were still healthy, and which were sulphated, etc.
I ended up with four functional 6v 10Ah batteries all less than 2 years old, that were very lightly used, for $5, and gave the other weaker unti back to the contractor the next day.
I now have the Braun running on 2- 6V10Ah, and 2- 2V 8Ah cells to give heaps of capacity before the need to charge them. I usually stand mount the head firing it into a 24x36 soft box, and hang the accumulator and batteries pack half way up the light stand to stabilize the whole affair. It makes a great light for shooting portraits on location at a theatre during rehersals for head shots of performers. Print of these photos end up being posted on the front of house display board, and scans feed to the program bios area.