Is A Dell Precision M4700 9-Cell 97Whr Battery Alternative Available?

Can a Dell Precision M4700 laptop --- that comes with a 97Whr 9-Cell Lithium-Ion Primary Battery with an ExpressCharge feature that enables the battery to recharge quickly --- use an 87Whr 9-Cell Lithium-Ion Battery that does not  have the ExpressCharge feature?  A Dell document (see below) says that the answer is Yes.

But when I search the Dell website's M4700 accessories, the only M4700 battery I find is the same as the 97Whr 9-Cell ExpressCharge capable battery that I already have.

However, I have found an 87Whr 9-Cell Lithium-Ion Battery (Manufacturer Part# : 97KRM | Dell Part# : 312-1176)  that apparently is not ExpressCharge capable, used in Dell Precision Mobile M4600 and M6600 laptops.  I found this 87 Whr battery at http://accessories.us.dell.com/sna/productdetail.aspx?c=us&l=en&s=dhs&cs=19&sku=312-1176

QUESTION:  Do M4600 laptops have the same battery location and connections that M4700 laptops have?  If they do, I am tempted to get the M4600 battery and use it in my M4700, even though the website's Compatibility list does not include the M4700.

[I have evidence that Dell doesn't always keep its Compatibility lists up to date.  Earlier today I purchased an exterior USB (Dongle) Modem (for faxing) for my M4700, even though its compatibility lists included only Latitude laptops.  Yesterday I confirmed with Dell's Technical Support that the modem would work fine with my M4700.]

BACKGROUND:  I purchased my M4700 earlier this year, and am in the process of setting it up.  It will be used primarily in my office, getting its power from the electric company, and protected by an APC Smart-UPS.

In my office my M4700 doesn't need an ExpressCharge feature because when in use it always will be plugged in, and power from the electric power company (assisted by the Smart-UPS) will keep my M4700 fully charged.  So if I can get an 87Whr non-ExpressCharge battery, I will use it when in my office (which is at least 99% of my computer time).

But when I am traveling with my M4700, I will use the 97Whr ExpressCharge battery, because that's when rapid re-charging is likely to be useful.

I got the idea of using different batteries for different situations from a Dell Document, entitled "Dell Precision™ M4700 –  M6700 Technical Guidebook," written by Mano Gialusis, Sr. Product Marketing Manager, and apparently released on 08 August 2012,  Pages 62 and 64 describe batteries for the M4700 and M6700 laptops.  The list includes not only my 9-Cell 97Whr ExpressCharge capable battery, but also a 9-Cell 87Whr battery that is not  ExpressCharge capable.  Both batteries use 3,0Ah technology.

The Guidebook (page 62) says that the 9-Cell 87Whr battery has a 3-year warranty, and "Allows users to use the same battery with longer life span than regular ones. 3year warranty battery can deliver a more consistent runtime after months of use and recharges, which helps to reduce total cost of ownership throughout notebook usage life cycle."

And it says also that "For a battery advertised as having the ExpressCharge™ feature, the battery typically will have greater than 80% charge after about an hour of charging with the system off, and fully charge in about 2 hours with the system off."

Those two statements suggested to me that it would make sense to use a different battery in my office than when traveling.  That thought was reinforced by reading about Boeing's battery fires possibly having been caused by excessive Dendrites, possibly created by too-frequent rapid recharging.

Full Disclosure re the Guidebook:  On many pages, in print so very light that I did notice it until today, the lower left hand corner states "Dell Confidential - NDA Use only."  (I have no idea what NDA stands for.)  I found the Guidebook somewhere on the Dell Website, while looking for information about the M4700 and M6700 laptops.  Unfortunately, I did not keep the website link where I found the Guidebook.  Also unfortunate is that the Guidebook did not include a Manufacturer Part# and/or a Dell Part# for the batteries.

R.N. (Roger) Folsom