I have just tossed some of my old Eneloop and bought a couple new.
These new ones show a manufacture date of October 2019, so they are 3years old minus a month.
Should I keep them or send them back?
Also is this ok to be sold that old, I can’t say I am happy to see I got 3yr old cells, but maybe it’s the norm to not be fresh.
I order from Amazon and they always give within 6 months.
You didn’t even come close to answering the questions. For myself OP, I don’t know. Given that Eneloops are suppose to hold a good part of their charge for 10 years, it likely does not matter.
My Eneloops have easily lasted over ten years, and are still going strong.
I don't understand how Eneloops could only last six months. 
...
Where did you get yours, Hikelite?
I think I would return the Eneloops if they were about three years old and sold as "new."
I mean, Eneloops last a long time, but three years old isn't very fresh.
They’re probably ok but I would still return them out of principle. If I’m paying for new products then I expect to get new products.
I don’t think anyone other than the manufacturer knows how Eneloops age in the package so there’s no sense in taking the chance of getting even slightly degraded batteries since they’re easily returned.
I will return them, actually I wanted to return them instantly since the 3yr old manufacturing date felt like getting old products, not new, especially with regards to cells.
My guess is it wouldn’t make a bit of difference . You may need to cycle them a few times since nimh can go to sleep . I’d cycle them and do an internal resistance test before making any decision . Also probably depends on what you paid for them too.
They here sealed, I could only return if unsealed.
Gotcha … I was thinking Amazon
I have in use white eneloops manufactured in september 2006… Manufactured 3 years ago are new for me, if genuines. 
If returns aren’t easy I think I would contact the seller and express your concerns. Ask them if they will accept a return just in case the cells aren’t in the best health. 3 years isn’t terrible but NiMh do like to stay charged up, and you have no idea what their storage temperatures were like during that time period after manufacture. Are you seeing the copyright date on the packaging or is there actually a manufacturing date that’s visible to you? If it’s just the copyright, it’s normal for those dates to be used/printed for a few/several years before updated.
Some years back I got two 4-packs of orange-wrapper Eneloops that seemed to be five years on….one of the eight was a lower capacity by about 400mAh. I was able to return that pack and get a replacement from the seller even though they were open. But most likely they’re just fine.
Meant to say manufactured within 6 months.
Okay, that make more sense.
I should have been able to figure that one out. 
I agree, should be < 3 months old when you buy them.
As OP stated, he purchased new and they were three years old. He is not asking how long eneloops last or what is your oldest eneloop.
I wouldn’t give them a second thought - I bought a whole bunch off a sun baked close out rack that were made in June 2006. They were all still at 60% charge (which is probably the shipping charge) when I opened them and they’re charging and running as if they were made yesterday. We run them mercilessly in everything from cameras to blood pressure cuffs, where they outperform alkies by 2:1.
If you dig through my post history you’ll find a big long thread about them. Those things are bullet proof.
They’re fine.
I bought two 8 packs of Eneloop Glitter 5th Anniversary Eneloops, date stamped 9/2012, in 2015 and they’re still at 100%, 10 years later.
Nothing burger.
Chris
Personally…… If they were regular Eneloops I would absolutely keep them.
But I would absolutely send the “PRO’s” back.
They were Eneloop Pro.
Interesting I have asked some other store about the date on their Eneloop Pros and they only said, old do not buy if you think that is not ok.
I assume probably also 2019-2018 as if I would have to guess no on would say old if they were only manufactured 1year ago, again I guess.
Are PROs not manufactured anymore? Or they are way less purchased that regular ones and it’s full of old stocks at this point?
The fact that old batteries purchased still work as new has nothing to do with the fact he purchased old batteries. Now if you told me he got them for 50% off because they were old stock is a completely different story.