Battery testing -- what do you want to know about your batteries?

Apologies for the wall of text. If you were not interested in a bait-and-switch, look for the bold text in brackets.

A few years ago, I started a modest attempt at testing various batteries, looking at the different characteristics between the many, many chemistry make-ups, designs, and the general tendency of particular manufacturers to either undersell or oversell their batteries specifications (as you might expect, I often couldn't reproduce too close to what they advertised). The most frequently purchased batteries, small alkalines, generally don't have even the most basic of information on their labels, though this may be due to their linear voltage dropoff, where they perform relatively well in low-drain applications with a generous operating voltage range, and poorly in high-drain, precision applications. The market in general is goofy, where nobody seems to care about specs, but are rather interested in whether their battery is heavy-duty, super-duty, or super-heavy duty - whatever the fuck those mean - and few realize how many batteries they thought were alkalines actually turn out to be ZnC. It's especially common on sites like Amazon, which do practically nothing to moderate their battery sellers who apparently have no qualm selling "new" 3-year-old lead-acid batteries with little to no useful information in the product description. In general, I think the consumer battery market is unusually ignorant and too exploitable by vague marketing, which I'd like to help correct.

I ended up too busy and set the project aside not terribly far in. My methodology was garbage, with a BS meter for testing. I'm intending to resume the project within the next year with better equipment, better control (and measurements of relevant conditions like temperature), and more relevant stats on the batteries operating results. I feel I'm a good bit closer to knowing what I'm doing. I'm doing this as a "casual consumer watchdog" venture, mostly just because I enjoy doing it (there are explosions!). While I was originally just looking to familiarize myself with different types and get a feel for how bullshit the marketing is, only looking at LR6, I'd like to include car/cart/motorcycle/boat batteries, LiFePO4 (and inferior) batteries for banks with regards to home (or SMB) energy production, UPS batteries, hobby car/boat/plane/whatever batteries, as well as restarting testing for "normal" consumer batteries. I think any market where you need to go to a B&M and talk to an "expert" on the

[Relevancy to OP starts here]
What I looked at previously was:
*Watt-hours (along with amp-hours, which battery packaging usually advertises even though it's an incomplete picture)
*Graphed voltage and watt output by amount of discharge (some batteries output a consistent voltage until it's fully discharged, others linearly discharge and could theoretically, if a 1.5V alkaline battery, still output enough amperage to power a device at, say, 1V output, and some others have really goofy curves and random-seeming dropoffs).
*Amp output over time.
*Cost per battery, $/Ah & $/Wh, Ah/g & Wh/g
*#times a rechargeable battery must be recharged to recoup costs compared to "best non-rechargeable" in the category
*Theoretical (manufacturer-claimed) cycle-life & theoretical degradation over time
*Environmental concerns (not experimental, obviously)
*Safe operating ranges with regards to temperature (experimental! Hooray, explosions!) -- additionally, testing at up to seven different temperatures to measure performance (below minimum rated temp, minimum rated temp, freezing, room temperature, hot (~125*F), max rated temp, above max rated temp)
*Effects of recharging a non-rechargeable battery (this is particularly fun, both for the explosions and unexpected results)
*Whether or not non-vented batteries of the particular type are safe to use under max load (they often are not, which I've repeatedly learned with cell phone batteries!)
*How to "clean" the battery in case you have undesirables "gunking up" your battery's internals
*"Battery's future" (heavily speculative, going over whether or not the technology's mature and what kind of projects are going on to improve key specs or reduce costs, talking to available experts, yada, yada, yada)

Really difficult stuff to put out which I'll think about:
*Redneck battery-venting (I'm pretty sure this isn't reasonable in any scenario, but who knows...)
*Experimental number of charges and discharges before "useless," as well as a chart going over degradation by time (this'd have to be far-future... I'm not dedicating $200-700 in equipment testing a single battery over 6 months of unrealistically constant charging and discharging.)

If you're interested in something else, do please let me know.
[Relevancy to OP ends here]

For keeping the project financially afloat, I'm interested in forming relationships with reputable manufacturers to lower or eliminate the cost of actually buying all these batteries (as well as getting a direct line to an engineer or few to talk to - though I'm leery about becoming "overly-involved" with a corporation), non-obnoxious referral links (both for consultancy and battery purchases), and creating a sister site dedicated solely to displaying video footage of batteries exploding (high FPS camcorder essential) which'll feature slightly more obnoxious and generalized advertising.

Initially, the goal is to grab ad revenue and a repeat user base with "tabloid" data collection/publishing which goes over exotic designs, earlier-mentioned explosions, and goofy/"innovative" ways to use batteries (maybe an article on... Idunno, building a steampunk electronic coffee maker with no IC, only supercapacitors, a heating element, and mechanical buttons). Ideologically, the end-goal is to have a search engine made for humans to use when they need a battery -- you could select a power-user search engine which assumes you can "build around the battery" and are just looking for "hard data" rather than whether the battery uses an F1 or F2 terminal or if it'll fit in the mounting brackets you have: what are you looking to power, voltage input requirements, "normal" temperature range and max temperature range of where the battery is expected to operate, etc -- it'll then give you a list of batteries with a full list of relevant experimental data and claimed specs for batteries which meet your demands and - this is what I'm really interested in - which battery is most cost-effective and/or hassle-free for your particular use scenario (frequent discharge and recharge, battery types which tolerates full discharge, high-capacity disposables, infrequent discharge and quick recharge, ultra-low self-discharge disposables). That one'd show all the data I've collected, full of graphs which allow even an industrial project to confidently figure out their "what ifs" without in-house studies and best guesses (while I'd be quite proud of this, I don't want to move to a paywall model and would be eminently surprised if a corporation gave a tip, so I'm unsure if there's any way to not be a martyr in offering this). You could also use a more hand-holding kind of search engine: what are you looking to power (if applicable, questions like "how large is the engine?"), voltage requirement, physical size of current battery, terminal size, if applicable, etc. - and this would spit out a good bit less information without charts, but still going over which battery type is likely most cost-effective and hassle-free. With many resources invested, this could become as simplified as "make & model of car," then giving the correct batteries and a general assessment on whether or not the person should consider a Li-ion instead of SLA or AGM, with relevant generic data on all the types, of course.