A brain storm regarding an extra laptop battery

Hey there, all. I was hoping you might help me overcome my ignorance and get a better idea for the feasibility and obstacles involved in the possible conversion of an xpal XP18000 (universal battery thingy) into a second laptop battery.

Now, I know I just lost about half of you to the thought, "oh good, another cheapskate who thinks he can save a buck with electrical wizardry," but I don't really think that's the case. In truth, I doubt it would be cheaper than just buying an extra battery for the laptop--it just sounds fun and insightful.

Here is what I know to begin with. The laptop is an HP Envy 15 with an internal battery, and tabs for a 9-cell "slice" battery to sit under the laptop (some info on the battery here here). Any ideas what I'm looking at? My assumption is that the battery is a standard-ish Smart Battery Specification 1.1 setup, but I don't actually have any evidence to that fact; maybe wishful thinking.

I'll be thankful for any information you may have!

dilleh

making any thing a laptop battery is bad for your laptop. the battery has controlled voltages and moreover there are many positives and negatives in the battery. even if you make a alike one, it should be a lithium one, coz you need constant voltage and high current. so you must not mess up and experiment. i myself have a business of rebuilding the laptop batteries. if you have problems with your battery then I could rebuild yours too. my cost is $7.5 per cell and guarantee is 1 yr. but shipping is to the customer. so dont mess with your laptop when you have a cheap solution available!!