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battery load test interpretation

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NutmegCT

NutmegCT

Great Pumpkin
Bronze
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Gentlemen - here I am with my daily "I'm an idiot" question:

How would you interpret the 12v car battery test result shown by the black diamond on the meter face? The HF tester manual doesn't mention the 200, 400, 800, etc. the black diamond shows where the needle moves to when the test is carried out: it's just barely in the green. But there are two green areas.

View attachment 26164

Thanks.
Tom
PS - the fuel test this afternoon showed no problem.
 
Looks like a hair over 11 volts.
Car running?
Only in the start position

Need more info, Tom
 
Thanks Don. The tester works like this: engine off, ignition off, leads connect to battery terminals, 100 amp load for ten seconds. Meter is read at the ten second point.
Tom
 
DOH>>>
Then I have 1 thing to say


RANDALL!!!!!
 
Huh? What? Somebody yelling my name ? Oh ...

The green area with the numbers is for the load test; the numbers are for different battery capacities. That is to say, a battery rated at 1000 CCA should be within the green area marked '1000' after the test; while a battery with only 200 CCA could be as low as the bottom of the area marked '200'.

Since you are within the '1000' area, the battery appears to be good, within the limits of this test. I'm running a much smaller (and lighter) battery that only rates about 700 CCA on the tester, and it will start the TR as long as it starts quickly (which it always does).

But old cars rely much more on the RC (Reserve Capacity) rating than modern cars do, so there is more to the story than just CCA (Cold Crank Amps). The TR will occasionally not start if I drove home in heavy traffic with the headlights on (because at low rpm, the generator will not keep up with both headlights and radiator fan). A battery with more RC would solve the problem (because it could supply the current for longer and still have enough charge to start the engine).
 
Thanks Randall! I was wondering if my (endless) starting problem in the MB could be due to a weak battery.

I charged up the battery (per the maintainer reading anyway). Then (engine and ignition off), after dark turned on the headlamps (low beam). After ten minutes I could tell the lamps were slightly yellow.

Desperately seeking reason - that the MB won't fire!
Thanks.
Tom
 
Pop...suck...and....fart....Tom
Does it have all?
 
My honest opinion after going back through all your posts is that you've got some nasty stale gas. Drain out the carb, get a fresh can of good gas, and run a hose out of the can into the fuel pump. Don't mix it with any of the old gas.
 
Thanks Ben. Wouldn't I accomplish the same thing by just emptying the carb bowl and filling it with fresh gas? If it fires, then I know the gas was bad. (right?) If it doesn't fire, then I know the gas isn't the issue.
Tom
 
That would work. In that case I would block off the fuel line somehow to prevent any of the suspect fuel from reaching the carb. I have seen several engines now refuse to start on fuel only a month or so old.
I could be wrong. Long distance diag is tricky. But that is my thought on what you are describing. I'd be happy to chat with you sometime if you want. just send me a PM.
 
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