The charity my wife is helping has been donated a bunch of middle age Dell laptops (E6440s) but without any batteries. Whilst I know they can run without the battery they would like to fit some before they are distributed to the people who need them. Dell want to charge a small fortune so a compatible make looks like best value for money. Does anyone have first hand experience of brands that aren't likely to explode? A quick Google shows they can be found from £25.
I don't have experience to draw on, but if I was keeping an eye on it whilst charging (and it was backed up/non-vital/remote access for work only anyway) then I'd certainly be prepared to try one or two at a time and see how they go. I need to replace my own and was thinking much the same; only reason I haven't yet is because it's not on the priority list.
I've bought cheap Dell laptop batteries and battery packs in the past, none lasted more than 1 or 2 recharges. The last one I took apart contain recycled (completely knackered) used 18650s batteries.
I've bought non-OEM cheapest well reviewed batteries from Amazon for Lenovo T420 and 2010-ish Dell Inspire. All worked fine as far as I can tell. Though both machines were used on AC power at their dedicated workspace most of the time, so were not under heavy daily use as one might expect from a laptop.
There appears to a few "branded" non-oem manufacturers. I assume at least some of them will be okay because there must be a large aftermarket need for laptop batteries. Just trying to avoid the stuff made of only hopes and dreams!