Testing batteries

[Donald]

The best test is the carbon pile load tester where you dial up 50% CCA and wait 15 seconds for the beep, then read the voltage off the temp compensated scale. You need the battery fully charged however for the best test. You also need to wait a few minutes for a second test, the sucker smells hot after a test. HF sells them.

The conductive testers do not require a fully charged battery and thus that is why the places that sell batteries like them. Quick test. The better (expensive) ones are temp compensated.

And don't rule out a hydrometer if you can get the cap covers off.

 

[Donald]

Originally Posted By: HTSS_TR
Originally Posted By: Nate1979
Get a good quality trickle charge, get them charged up as good as possible. This will do wonders for your battery life and could allow you to get another year out of them. I also had a Panasonic battery on our Subie. Was about 5 years old and was tested as weak by some test by Firestone (no clue how good that was). Started putting it on trickle charger on regular basis and got another year out of it no problem. Next time it was tested at the store it was now showing strong but was starting to leak so I replaced it with an Interstate from Costco.

Or get a cheap trickle charge - maintainer on eBay for less than $8-10. Hook up the charger overnight on weekend once a month. It may extend the life of battery some months or a year.


A trickle charger is not a battery maintainer, although terms do get misused.

 

[meep]

1. park car, engine off.

2. turn headlights on for 45-60 minutes and walk away

3. try to start car.

more realistic scenario than a $ tester..

 

[Donald]

Originally Posted By: meep
1. park car, engine off.

2. turn headlights on for 45-60 minutes and walk away

3. try to start car.

more realistic scenario than a $ tester..


I think a carbon pile tester would be much better than this. How would you judge the battery condition? By how fast the starter seemed to turn over the engine? Very subjective.

 

[supton]

Leaving lights on for an hour seems like a surefire way to kill a battery, by simply running it way down.

I'm not even sure I can do that, I think both vehicles would require engine set to on, which likely has the ECU etc powered up. Otherwise it'll just turn the lights off after like 5 minutes or so.

 

[Quattro Pete]

Originally Posted By: supton
Leaving lights on for an hour seems like a surefire way to kill a battery, by simply running it way down.

I accidentally left my lights on the other day. Thankfully when I pull out the key from ignition, the headlights switch off, so only the parking lights stayed on, but they stayed on for 13 hours. I was kind of surprised I was still able to start the engine afterwards.

 

[HTSS_TR]

Originally Posted By: Donald
Originally Posted By: HTSS_TR

Or get a cheap trickle charge - maintainer on eBay for less than $8-10. Hook up the charger overnight on weekend once a month. It may extend the life of battery some months or a year.

A trickle charger is not a battery maintainer, although terms do get misused.

There are some trickle charger - maintainer on eBay.

I bought one and according to the Kill-A-Watt and power meter it did just that.

The first few hours it used 25-30 watts and power meter showed it charged the battery at 13.8-14.5V with 0.8-1.2A.

It then went to maintainer mode consumed 4-5 watts charging battery at 14.3-14.5V with 0.1-0.2A.

Disconnected the cables from battery it consumed 1.8-2.0W.

When I don't drive my S2000 for few days I hooked up the battery maintainer, since it uses only 4-5W the electricity cost is no more than 1-2 pennies a day.

 

[circuitsmith]

I drive mostly 2-3 times a week, 30 minute stop-and-go trips.
Every 2-3 months I charge the battery 12+ hours with an adjustable power supply set to 14.5V.
Once a year I do an equalizing charge by cranking the voltage to 15.5V for an hour after the long charge.
My last battery was going strong at 9 years old but last October I decided not to chance a 10th winter.

 

[Nate1979]

The one I bought was a noco genius 3500. Works great. I maintain about 5 different batteries so if I maintain or increase their life just a little it pays for itself easily.