Don Terrill’s Speed-Talk

I am in phila. we race from march to november. I drive mine every week or so during the winter. How do you test your battery for the coming season Oldhead

Touch it to your tongue, lick it.

Do you do that alot

oldhead wrote: ↑Sat Jan 06, 2018 7:10 pm I am in phila. we race from march to november. I drive mine every week or so during the winter. How do you test your battery for the coming season Oldhead

Do a full recharge, if its holds more than 12.8V after an hour you good to go. (assuming its a 12V batt)

You can take to Oreillys and have them do 1 hour load test.

To properly test a battery you really need a carbon pile type of load tester where you can crank up say a 400 amp load and watch the voltage. A good healthy battery will pull down but when the load is removed return to near its full voltage over and over again. A weak battery will fall off to less than 9.5 volts very quickly and not recover. Cheap electronic battery testers will not do this.

DaveMcLain wrote: ↑Sat Jan 06, 2018 8:52 pm To properly test a battery you really need a carbon pile type of load tester where you can crank up say a 400 amp load and watch the voltage. A good healthy battery will pull down but when the load is removed return to near its full voltage over and over again. A weak battery will fall off to less than 9.5 volts very quickly and not recover. Cheap electronic battery testers will not do this.

Now this sounds like a real load check,How low do you take the volts on the pull down?????Oldhead

https://en.wikipedia.org/wiki/Lead%E2%80%93acid_battery

Discharge at the 10 hour rate and calculate capacity.

This info. is to old its from 1859, My battery is newer Oldhead..PS:Are you that old?

The Midtronics style of tester is used by most shops these days. Many auto parts stores will test your battery with one for free. I’ve used one for over ten years now.
http://www.midtronics.com/transportation

O'Rielly's uses the AutoMeter battery tester and charger now.

Absolutely the very best battery tester is an old Sun VAT-28 carbon pile load tester.

With all the batts on our farm I bought a Solar BA-5 tester a few years back that will check volts CCAs and such. Best piece of test equip I ever bought. Plug.

Or for 50 dollars or less you could try this.


https://www.youtube.com/watch?v=iFCCF6extfQ

OTC 3180. is an old school tester that monitors voltage while asking it to discharge at about 100 Amp rate into a big old resistor. Makes some heat ( 1200 watts) so the test should only be run for 10-15 seconds. The old Carbon pile is likely better, but it it will bring a marginal battery, or under charged battery to it's knees.
https://images-na.ssl-images-amazon.com ... L1170_.jpg

They have got pretty cheap recently.

Works on 6 and volts, and has a decent analog volt meter built in to test alternator charging, too

DaveMcLain wrote: ↑Sat Jan 06, 2018 8:52 pm To properly test a battery you really need a carbon pile type of load tester where you can crank up say a 400 amp load and watch the voltage. A good healthy battery will pull down but when the load is removed return to near its full voltage over and over again. A weak battery will fall off to less than 9.5 volts very quickly and not recover. Cheap electronic battery testers will not do this.

Good test, but not always accurate. Had an older yellow top battery in my truck. Started running into a slower cranking issue. Took it to the store under warranty. Never dropped below 10.8 volts on load test but would not charge above 11.2 regardless. Yes, it still started the truck but cranking speed was down....I can't tell you why it did that, only that it did.....