Precision 7530: help me choosing the right battery

Hello,

I am going to purchase a Precision 7530. However, 3 different batteries are proposed by dell in Belgium:
-lithium-ion / 4 cells / 64 Wh+ExpressCharge - base price
-lithium-ion / 6 cells / 97 Wh+ExpressCharge - +16,25€
-polymer lithium-ion long-lasting / 6 cells / 97 Wh+ExpressCharge -+20,01€

1. Does any of the 97 Wh cells prevent the installation of a second HDD?
2. Does ExpressCharge really shorten the charge time? How much?
3. What does "long-lasting" mean: does it mean the battery keeps the charge for a longer time? How much longer, then? Or does it mean the battery will have a longer life globally?
4. Is it worth to take the option of the extended battery life with either type?

Thank you in advance.

 

1. This system supports 4x M.2 SSD drives, or 3x M.2 SSD with 1x 2.5" SATA drive. With the 97 Wh battery, you cannot install a 2.5" SATA drive. You can still install four drives, but they have to be all M.2 drives.
2. Yes, ExpressCharge does shorten the charge time (cut in half, about?) but I believe it will also wear out your battery faster.
3. It seems that the battery is the same; they just take away some options (like ExpressCharge) and grant you a longer warranty. It does not mean that your battery will last longer on a charge. That it totally determined by the Wh spec.

 

Thanks a lot for the... ...precisions!

 

This might not apply, but if you got the UHD screen -- Dell has been shipping 7530s around spring/summer of this year with a bad lot of SHP1430s. Manufacture date week 36, 2015.

They had an UHD shortage -- not enough screens to supply the 7530 and 7540 -- and instead of pulling the option from the 7530's config earlier (last I checked, they finally did remove the UHD) or telling buyers 'whoops sorry' they started shoving defective 4+ year old screens into new 7530s.

I am weeks into this with Dell's Round Rock USA staff; first they told me there were no complaints about it, then they told me there are no current complaints, and now they've really torqued me off.