Looks similar functionality as the ctek there Gary. Got the ctek for £62 off ebayIf your looking for a mains battery charger, I have one these
Ring RSC612 12A Smart Battery Charger. https://www.amazon.co.uk/gp/product/B00S8969OG/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
Seems to do the job.
G.
I would say there’s nothing wrong with that at all Chris. I suppose the only thought I might add which one would probably do anyway would be to switch the charger off before disconnecting the slave battery, perhaps leaving for a few minutes in case there’s any hydrogen around which I would say was unlikely if only on for a short time. I’ve not had a problem yet and have resurrected a really low Varta for the cursed Smart car without hassle.When trying to raise a battery from the dead (which my CTEK does) you can couple another good battery to it in parallel. So if you only have a lower amperage charger slave another battery with jump leads or whatever to effectively 'fool' the charger. Probably the right method but wrong science. Anyway, it works.