Really wish I could find the u27-36xpd for £90 each at the moment.Yeah £500 each is way over the top but hey they are yours to do with as you wish , I got mine on eBay at a very keen £90 a battery I bought 10 , I wish I’d have bought more but I wasn’t sure if they would be useful at the time of purchase.
Are yours the u27-36xp batteries ? Fancy putting up a picture or two ?