Battery volts vs cranking power?

[Silvertip]

Re: Battery volts vs cranking power?

Actually, its not quite peak current. The rating is the amount of current that can be produced for 30 seconds @ 0?F before the battery voltage drops to 7.2V. Its a combo of peak current and capacity to keep outputting that peak current.

Reserve amp calculations have absolutely nothing to do with CCA ratings either as its more a capacity rating.

Read here for some accurate info for CCA and Reserve capacity
http://www.autobatteries.com/faq/index.asp

Another thing, a charger can bring up a battery to full charge and the battery can fail a load test. The charger will still be good. If the battery capacity is low because of age, it will still fully charge.

Agreed!~ but it does no good to take a discharged battery in for a load test as it will fail. Doesn't matter if the battery is actually dying, dead or just needing to be charged. If the battery is fully charged for the test and it fails -- THEN you need a new battery.

 

[rebars1]

Re: Battery volts vs cranking power?

Will do re getting the battery (fully charged) load tested.

It was mentioned to use a " maintenance charger to keep it topped" when not in use. The boat is kept in dry storage yard at the lake. Is there a solar powered trickle charger that could be used to keep the charge up without over charging the battery?

 

[Bondo]

Re: Battery volts vs cranking power?

Will do re getting the battery (fully charged) load tested.

It was mentioned to use a " maintenance charger to keep it topped" when not in use. The boat is kept in dry storage yard at the lake. Is there a solar powered trickle charger that could be used to keep the charge up without over charging the battery?

Ayuh,.... There's Oddles of 'em,... Google it...

From dirt cheap junk, to hi-end powerplants...

 

[UncleWillie]

Re: Battery volts vs cranking power?

Will do re getting the battery (fully charged) load tested.

I just know this is going to cause a stir.

Load testing is just putting a load on the battery and seeing how well the battery holds up.
You have everything you need to do this yourself.
What you require the battery to do, is to start the engine reliably.
Hopefully it starts cold in less that 5 seconds.

Here is the test...

Charge the battery until it is fully charged.
Now stop charging and let it sit for 12-24 hours. (Will it hold the charge?)
Battery voltage should read 12.6 (+-0.1) volts.

Disable the ignition to the motor so that it will not start when cranked. (Safety lanyard Switch Off, Coil Wire Off, etc.)
Optionally, Place the voltmeter leads directly on the Battery Terminal Posts. (NOT the Battery Clamps!)
While watching the voltmeter. Crank the engine for 15 seconds. (Actually time it, Don't guess!)
Voltage stays above 9.5 volts on the battery Posts? (It will NOT read 12 volts while cranking!)
If you do not have a voltmeter, just crank and time it.

Let the Starter cool for 5 minutes and try it again.

If the battery will crank the motor for a total of 30-45 seconds and the battery voltage stays above 9.5 volts while cranking, what more can you ask for?

If your engine normally requires 25 second of cranking to start and you find the battery will only crank the engine for 30 seconds; you now know you have been living on the edge!

Don't forget to charge the battery again!

 

[rebars1]

Re: Battery volts vs cranking power?

Like they say..."One field test is worth a thousand expert opinions".

 

[UncleWillie]

Re: Battery volts vs cranking power?

Like they say..."One field test is worth a thousand expert opinions".

As long as you are doing the field test.... Good for you!

If the motor will not crank as you said, Start at the battery, measure the voltage While Cranking.
"Low Voltage" means any voltage significantly different than whatever was measured in the previous step.
Perform these tests, In Order, Do Not skip around or you will be replacing the wrong part!
Two People will make this go a lot faster.

NOTE: All tests are performed while attempting to crank the engine.
*** DO NOT hold the Starter ON Continuously! ***
It should not take any longer that two second for each test to get a voltage measurement.

REMOVE ALL Jewelry, Rings, Watches, Bracelets, Necklaces, Anything metalic. No Kidding! DO IT!
This warning is not like, "Always wear your life jacket."
This warning is more like "Don't Point a loaded gun at your head!"

It does not matter that the engine does not actually crank.
If it actually cranked, you would not be doing the tests in the first place!
What matters is that the starting circuit need to be energized.
The Starter/Solenoid should Click (Bad!) or Repeatedly Click,Click,Click (Not as Bad!)
No Clicking? Battery is Totaly Dead, or it is not a Battery circuit issue at all.
The purpose of the tests is to determine Where the voltage drop happens.
That is Where the problem lies.

If a Low voltage is measured while Cranking with the ...

Meter Leads on Battery Posts? ... Bad Battery!
Meter Leads on Battery Clamps? ... Bad Clamps or Connection!
Neg Meter Lead on Engine Block; Pos Meter lead on Pos Battery Post? ... Bad Neg. Battery Wiring to Engine Block!
Neg Meter Lead on Neg Batt Post; Pos Meter Lead on Starter/Solenoid? .... Bad Pos. Battery Wiring to Starter/Solenoid.
Neg Meter Lead on Engine Block; Pos Meter Lead on Starter/Solenoid. Voltage still Good? Bad Starter/Solenoid.

If you have a Solenoid that is seperate from the starter, Continue working your way out to the Starter one connection at a time untill you find the Voltage Drop/Hot Connection.

Be carefull. If you find a bad connection, it will drop a lot of voltage, it will also get Very Hot, Very Fast.
Do Not yell "Eureka" and immediately put you finger on the problem. Burns are painfull!

Post your results.

 

[bruceb58]

Re: Battery volts vs cranking power?

Or just buy one of these to load test your battery.

http://www.harborfreight.com/100-amp-6-volt-12-volt-battery-load-tester-90636.html

Then you can look further for other things if it tests ok.

 

[NMShooter]

Re: Battery volts vs cranking power?

Couple of things...

X3 on the hydrometer. I bought one today at Autozone for $4.99 only good way to tell if your battery is charged or not, as even a bad battery will float to a higher voltage when not being used. The suggestion of a crank test is a good way to load test your battery, but for $5 you can get a hydrometer that will tell you the exact condition of ALL the cells, which is good for knowing when you need to do an equalization. Just get one and learn how to use it. For deep cycle batteries, full charge is ~1.267s.g., and 50% charge is 1.190s.g.

I just bought a Sam's club energizer 29HM battery for about $80. I used it this past weekend with a minnkota powerdrive trolling motor. Had it at half speed for about 3 hours, and only used about 15% of capacity.

 

[joed]

Re: Battery volts vs cranking power?

I just know this is going to cause a stir.

Load testing is just putting a load on the battery and seeing how well the battery holds up.
You have everything you need to do this yourself.
What you require the battery to do, is to start the engine reliably.
Hopefully it starts cold in less that 5 seconds.

Here is the test...

Charge the battery until it is fully charged.
Now stop charging and let it sit for 12-24 hours. (Will it hold the charge?)
Battery voltage should read 12.6 (+-0.1) volts.

Disable the ignition to the motor so that it will not start when cranked. (Safety lanyard Switch Off, Coil Wire Off, etc.)
Optionally, Place the voltmeter leads directly on the Battery Terminal Posts. (NOT the Battery Clamps!)
While watching the voltmeter. Crank the engine for 15 seconds. (Actually time it, Don't guess!)
Voltage stays above 9.5 volts on the battery Posts? (It will NOT read 12 volts while cranking!)
If you do not have a voltmeter, just crank and time it.

Let the Starter cool for 5 minutes and try it again.

If the battery will crank the motor for a total of 30-45 seconds and the battery voltage stays above 9.5 volts while cranking, what more can you ask for?

If your engine normally requires 25 second of cranking to start and you find the battery will only crank the engine for 30 seconds; you now know you have been living on the edge!

Don't forget to charge the battery again!

Exactly why asked what was the voltage while cranking way in post #9.