Community Forums

Long Island Mac · 08-15-2018, 07:59 AM

How to check for sulfation on a sealed battery. Batteries show 13.6 volts, but mechanic said if sulfated, might show good, but won't turn over engine?? When key on, DASH kites, but zero when turned to start??.

Finance · 08-15-2018, 08:47 AM

Cranking batteries should be tested using a load tester.

hivoltage98 · 08-15-2018, 08:54 AM

https://youtu.be/6x-JfckAt20

Tha_Rooster · 08-15-2018, 10:09 AM

Quote:

Originally Posted by Long Island Mac

How to check for sulfation on a sealed battery. Batteries show 13.6 volts, but mechanic said if sulfated, might show good, but won't turn over engine?? When key on, DASH kites, but zero when turned to start??.

Odds are if it jump starts you have a bad battery.

Gary RVRoamer · 08-15-2018, 10:22 AM

You can't check for sulfation on a sealed battery and your mechanic is just guessing, throwing technobabble at you. Doesn't make any difference - the battery is shot. It fails under a high amp load, which is in internal battery failure.

Dutch Star Don · 08-15-2018, 05:17 PM

Just a note....Many coaches come with the Interstate sealed batteries for starting batteries. If you look closely at the label on top, you can see the outline of the battery caps.

If you take a razor and slit along the lines, remove the label and then the caps can be removed and checked for water.

Long Island Mac · 08-16-2018, 06:47 AM

Thanks for all info. Checked under load (top charge taken off). Jumped with a 50 amp start, nothing. Possible have to leave that on for a few minutes. Any one know of relays or something to check?? Called REV.....no help as built by NAVISTAR, even tho same plant and probably same workers.

TQ60 · 08-16-2018, 10:13 PM

Stop...

Get voltmeter and check voltage at battery.

Needs to be about 12.6 if charged.

If less than 10.5 it is dead, less than 12 it should work.

Next while helper tries to start it see if voltage moves.

If voltage drops a bunch then battery problem.

If battery voltage does not flinch then a control problem.

Next check connections.

Place one lead of meter on center of post and other lead into the terminal attached to post and repeat.

Any voltage indicated here is bad connectiin.