I recently purchased a new Spark "Fly More Combo" from an authorized online distributor.  I was disappointed to find the unit was manufactured in July 2017.  So first off, the batteries are the old style before the upgraded latch.  Besides that they've been sitting on a shelf for over 18 months.  One of the batteries would not take a charge at all.  
The distributor has a 'any reason' return policy.  I contacted them and told them I was unhappy about getting such old stuff, and received return authorization for both batteries.   I was lead to believe they replaced them with new batteries.  But when I got them back I got my old 'good' battery back and another battery that was manufactured in August 2017.  Both batteries are fully charged now.

I've yet to activate my Spark.  The controller did take a charge.
I'm considering sending it back and getting a refund then purchasing elsewhere to get fresh hardware.

What are your thoughts?  How long can I expect these batteries to last?  Am I being a jerk or am I justified to feel like I'm getting ripped off?

Thanks

If stored with the proper charge (about 60%) and at the right temperature a battery should have a shelf life of several years and good for over 200 discharge/charge cycles.

ssylca44 Posted at 1-18 14:47
If stored with the proper charge (about 60%) and at the right temperature a battery should have a shelf life of several years and good for over 200 discharge/charge cycles.

Does sitting on a shelf for 18 months while 'new' before being sold adversely affect the battery life?

gscott Posted at 1-18 15:21
Does sitting on a shelf for 18 months while 'new' before being sold adversely affect the battery life?

The typical estimated life of a Lithium-Ion battery is about two to three years or 300 to 500 charge cycles, whichever occurs first. One charge cycle is a period of use from fully charged, to fully discharged, and fully recharged again. Use a two to three year life expectancy for batteries that do not run through complete charge cycles.
Hope this helps , but I gotta say I wouldn't like thinking I paid full price for something that was out dated either

I'm still flying with my Mavic Pro battery that came with it in jan 2016 and still getting 18 mins of flight time.

Woe Posted at 1-18 19:50
I'm still flying with my Mavic Pro battery that came with it in jan 2016 and still getting 18 mins of flight time.

It gives us hope!

It really is determined by the level of discharge you fly down to. If you go below 40% you are reducing the number of cycles thee battery can provide.

Remember you must fully discharge and recharge every 3 months to allow the Smart battery technology to determine the watt hours the battery can hold at its current age. Otherwise the "fuel Gauge" will be wrong.

Hello and good day gscott. Thank you for the inquiry. The DJI intelligent battery’s life depends on many factors. Normally, the battery can be charged or discharged 400 times. Thank you.

gscott Posted at 1-18 15:21
Does sitting on a shelf for 18 months while 'new' before being sold adversely affect the battery life?

Not really getting an answer to my question.     Does sitting on the shelf, NEW, UNUSED, for 18 MONTHS, before I got it and charged for the FIRST TIME, adversely affect the batteries?

i suggest that you buy the dji spark from the actual website but the average batteries last about 16 minutes but i prefer getting the spark from the dji website cuz that's how i got the spark, i will gladly give you the link if you want me to.

Woe Posted at 2019-1-18 19:50
I'm still flying with my Mavic Pro battery that came with it in jan 2016 and still getting 18 mins of flight time.

#metoo. I have 3 Mavic Pro batteries that are 3,5 years old. I treated them pretty good, always stored them around 50%, self-discharge set 2 days. But I do notice an increasingly bigger difference in sport mode, compared to a 4th battery that's newer. They drop faster than they used to, but that's pretty normal.

Bitmaster Posted at 11-17 05:07
#metoo. I have 3 Mavic Pro batteries that are 3,5 years old. I treated them pretty good, always stored them around 50%, self-discharge set 2 days. But I do notice an increasingly bigger difference in sport mode, compared to a 4th battery that's newer. They drop faster than they used to, but that's pretty normal.

....

DJI Stephen Posted at 2019-1-19 15:35
Hello and good day gscott. Thank you for the inquiry. The DJI intelligent battery’s life depends on many factors. Normally, the battery can be charged or discharged 400 times. Thank you.

This is not true at all. The official number of the LithiumPolimer (LiPo) battery charge-discharge cycle is 300 cycles.
High Voltage LithiumPolimer (LiHV) has a lifespan of 150-200 cycles.
The latter is also in Spark. So what you say has to be divided by two and even less (150 cycles) is the probable lifespan.

I purchased a DJI Marvic Are on 2018 with 5 batteries, the last flight was Jun 2020 with total 15 flights. However, on May 2021 I found both the controller and the drone cannot started no matter charged the batteries how many times. The controller and all the drone battery only  flash one time and turned off. If I had have known the DJI battery  can only for two years with 15 flights, I had would not bought 5 batteries and wasted so much moneys!

djiuser_b6vyAxw39HX5 Posted at 2021-6-2 10:57
I purchased a DJI Marvic Are on 2018 with 5 batteries, the last flight was Jun 2020 with total 15 flights. However, on May 2021 I found both the controller and the drone cannot started no matter charged the batteries how many times. The controller and all the drone battery only  flash one time and turned off. If I had have known the DJI battery  can only for two years with 15 flights, I had would not bought 5 batteries and wasted so much moneys!

Most likely it was not the passage of time that weakened the batteries while they were stored after those 15 flights.  Forgetting to periodically charge and fully discharge the batteries at specific intervals would gradually diminish the batteries' capacity to hold a charge.

I bought a Phantom 3S back in 2017, but never found time to fly it until 2019, at which point I found that both the brand new unused batteries I purchased with the drone were ruined because I failed to charge and discharge them during that period of storage.  I wound up buying 3 new batteries that I use to this day.