KenO wrote:
Appreciate any recommendations concerning software to test Li Ion
battery packs.

Thanks

Ken
You need to be much more specific about what you want to test and why.

I'll use the term "become unusable" instead of "fail" cause lithiums
used according to their design specifications rarely "fail".
For example, lithium batteries in laptops become unusable because of
increased internal resistance. The reduced voltage under peak load
causes the protection circuitry to report lower capacity and turn
off the system. There may
be many watt-hours left, but the protection circuitry won't let you
have them. I've taken packs that wouldn't run a laptop for 10 minutes
and tested them at lower current. I got almost ALL of the original
watt-hours out. I've switched to testing individual cells for internal
resistance.

One symptom of this in older laptops is that the system reports 100%
charge and starts dropping normally down to some lower level,
like 40%, then jumps to near zero and the alarms go off. Depending on
the details of the protection, the laptop may run for another hour while
reporting near zero capacity.

It's quite possible to correct for much of this, but there
are at least three problems.
1) Vendors don't care if you have to buy a new battery...margins are
MUCH better. The higher the cost of the battery, the more likely
you'll buy a new laptop. I buy used laptops. The cost of a used
laptop with a good battery is less than the cost of a new battery.
2) Less complexity costs less and you'll buy the cheaper laptop.
3) Any deviation from the industry norm invites lawsuits if
something ever catches fire. Vendors are much more worried
about a multi-zillon dollar lawsuit than you being ****ed
over a $100 battery.

So, the best test is one that simulates the usage.
For a laptop,
I keep the display on and play mp3's until it quits. How long it
runs is ultimately what matters.