We had one (a PulseTech 490 PT) in our labs and
they are quick but not very informative and many times, dead wrong.
A true test of a battery is done with a load tester and something like a
Progamma Torkel 860 to measure the capacity which is time consuming.
No shop would use one or could afford one other than a battery testing
facility.
LAB? OK we are talking flooded lead acid battery..... OK
I tested some friends battery, new batteries, pampered batteries, they had
12.73 volts, showed higher than their 730CCA rating. The Min voltage
during start was above 9 volts. I am 100% sure these batteries are GREEN
Light. Mine a three year old had CCA just below, resting voltage 12.6, start
voltage 8.7v. My point, my battery is very good but relatively less strong than
my buddies new batteries. Do I have 1 year, 2, 3 or 4 more years? Don't know.
I would like to never replace it again before I sell car.
Batteries are not all the same, even new. There are better designs,
materials, recycled lead, virgin lead, manufacture defects, short cuts, etc.
A friends battery had constant terminal corrosion. Replaced the battery,
problem solved; small crack in case caused electrolyte leak.
As a battery dies, some go fast, plates short, some just lose capacity,
slowly. I am not expert on the chemistry of FLA batteries, but eventually
the plates get sulfated. Can you "re-condition" a battery. There are videos,
de-sulfating chargers and powders (epson salt) people throw in, swear by.
Personally I don't like dealing with sulfuric acid. I have tried some of this
and milked a battery along. As long as you drive every day, the charging
system is strong, temps are moderate, engine easy to start, you can get
more time out of the battery.
However if your "weak" but working battery sit, temps get extremely cold,
it will let you down. It's that "reserve" power that we love. Leave the lights
on for an hour and it still start the car in a blizzard, we are good. This tester
will just give you a warm fuzzy if your battery is strong or middle-O-road,
weak or DEAD, but DEAD is pretty obvious, won't hold a charge, won't start.
Even my Schumacher battery charger will tell me percent charge, volts and
if a cell is shorted or battery is not taking the charge.
This little tester is just one indication. It is a parameter the owner/hobbist
could not test before. Electronics get more sophisticated, cheaper, we get
cool testers.
I work on electronics for fun. Last 10 years small $50-$100 capacitor testers
have become popular. Before capacitor bench testers that were $1000's and
required you to take capacitor out of the circuit board. The bench testers actually
charged (high volts) and discharge the capacitor. The small testers uses some
cool principles which allows you to test capacitors "in circuit". Not having to
take the capacitor out the board is priceless. Would I still like an expensive
"lab" capacitor bench tester, ones that cost $5000 new but now can be had
used for $500? Yes! I don't have room and the small tester is good enough.
Capacitors are like small batteries. In the size capacitors I use, they are
cheap enough to just replace. Large capacitors you really want to do a high
volt test, out of the circuit, and they are expensive. You don't just shotgun
them in to see if it fixes the circuit. Small testers are still awesome tools.
Back to batteries. Although prices have gone up, they are not that expensive.
Just replace it if it is suspect. This tester helps you know how strong or weak
the battery is.... "relatively" speaking.
The best "car" battery technology I have seen recently is a HANDLE on the
battery. It makes it easier to install and remove. AGM like Odyssey is really
a great technology (but it has pros and cons). Electric cars use Lithium-ion.
Prius used nickel-metal-hydride technology but has gone to Lithium-ion.
Rechargeable consumer batteries use Ni-Cad, NiMH. They all have pros & cons.
Cost, power density are factors.... My motorcycle has a lithium-ion replacement
for the original FLA. It's three times the price. The dream is a small light high
energy density battery, holds a charge for long time with out loss, has ample
"reserve" power and lasts forever. Batteries are still limited, but the old FLA battery
is still around because they "work" for a while. I suspect they may fade for newer
battery technology yet developed (we can hope). FLA for the price can deliver
+700 amps surge for about $100.
Oh and if you don't want to buy tester, and need battery/car test, AutoZone,
Advance Auto or O'Reilly will test your battery and charging system for free.
One of them (forgot which one) has a very good automated tester; even the
"rocket-surgeons" behind the counter can't screw the test up too bad... it
even has printer with results.