Cheap battery in the UK that fits and works, so far

After another genuine Apple one lasted well under 400 cycles over 18 months, and with them costing £109 here, which feels high, and is maybe 1/3 the value of the computer... I took a punt on a 3rd party replacement.

GRS battery A1151 A1189, Apple MacBook Pro 17

Mine was sold directly by Amazon, so I'd no concerns about easily returning it for a refund if it was rubbish.

These are early days, but it seems very good so far, fitting quite well (slightly shallower than the real thing) and functioning entirely as expected.

There are certainly bad ones out there, and a sample of one isn't the least representative... but it's worth considering.