wrote in message
...
On Thu, 15 Dec 2016 18:13:01 -0800, Larry Jaques
wrote:

On Thu, 15 Dec 2016 08:46:53 -0500, "Jim Wilkins"
wrote:

.......

I keep track of starting battery condition with an HF carbon pile
tester by reading the current when the voltage needle is at the 10V
pass/fail step. Autozone measured the starting current the (warm)
truck actually draws with their hand-held tester. Although it needs
more current when cold it would be in the driveway where I can plug
in
a charger.

Did you get the 100 or 500W model? Was it worth it? I used to have
a
nice Sun battery tester with pile at work. 0-500W with a huge
dial-up
knob and built-in VOM. Wish I had one now.

The one I had was a 500 amp one - thats 6000 watts.

The HF carbon pile has a 15 second timer to warn you to grab the
reading and turn the current down. Since it's unstable at low current
/ light pressure I didn't attempt to determine how much power it could
handle continuously. My guess is less than 100W, from comparing the
disk stack to wirewound rheostats of similar size. The timer circuit
limits the voltage it could withstand.

The manual specifies:
"15 seconds per test with 1 minute cool down"
"3 tests in 5 minutes maximum"

500A is claimed to test a battery rated at up to 160 amp hours or 1000
cold cranking amps.

When the battery on my main vehicle was drained by leaving the hatch
ajar for a week I replaced it to avoid the risk of getting stuck
somewhere in frigid weather - right now it's 3F outside.

I traded in a junk battery and kept it and it's still good for 150A at
16 years old. The HF load tester is to help me squeeze more life from
batteries I don't depend on.
--jsw