+- Rawze.com: Rawze's ISX Technical Discussion and more (http://rawze.com/forums)
+-- Forum: Big Truck Technical Discussion... (/forumdisplay.php?fid=1)
+--- Forum: International Trucks Related Help (/forumdisplay.php?fid=69)
+--- Thread: Not fully charging batteries (/showthread.php?tid=8494)
Not fully charging batteries - Trey7981 - 10-14-2022
I read on this site to check grounds. I'm assuming the grounds mean batteries, Body, frame, and engine. Well I can only find the battery grounds. Anybody can post a pic of where I need to look I have a 2016 PS isx15. Alt did run at 14.1v but now 13.2v to 13.6v with a meter at the back of the alt. Shop says it's fine. Well something has changed in the 2 years I've owned it. I did change the battery ground and positive cable. And if it matters I have an epu. Batteries where tested. One was bad.
RE: Not fully charging batteries - hhow55 - 10-14-2022
Being one battery was bad, hopefully you replaced all of them.
RE: Not fully charging batteries - hhow55 - 10-14-2022
No matter what type of batteries your truck has, to be cost effective long
term, you need to always ensure that the batteries are not only of the same type,
and capacity, but also close to the same age. Keeping your batteries as a 'Matched
Set' as much as possible will increase their lifespan greatly. As a comparison to
this analogy, think about your truck engine for a moment. What do you think
would happen if each cylinder of your truck engine was a different size and/or
type. Your engine would not only run very rough, but the cylinders doing the most
work will always cause you the biggest problems. Truck batteries need to be the
same capacity, type and roughly the same age to ensure they perform together as a
group. Buying used batteries, and/or mis-matching them will only result in more
battery problems long term, costing you unnecessarily.
Btw, this is from Rawze book.
RE: Not fully charging batteries - Bengy88 - 10-14-2022
Hhow55 and rawze are correct. I spent 3 days in class for just batteries when i worked at ryder. if you can imagine that boring shi#t lol. There is ALOT more to a battery than voltage that you see.
Now with that being said my first step is to test my voltage directly at the alternator, verify wether it matches the guage or not. If it does then your problem is most likely in the alternator... Usually a bad or dead battery will cause an alternator to overcharge. If it doesnt match the guage then is possible your guage is shi#t but you should still check your voltage drop from the alternator to the batteries. Then from batteries to the cab. If you follow your circuit from one point to the next all the way down the line you will find the issue. Oh yea dont forget to check powers, grounds, and voltage at the starter.
An amp clamp and learning how to properly use one also helps in situations like low voltage and cranking issues. For future refrences
RE: Not fully charging batteries - Trey7981 - 10-15-2022
Ok, my truck has 8 batteries. 4 for the truck and 4 for the epu I replaced the 4 for the truck as that was the bad batteries location. Should I replace the other 4 as well or is that a separate system. And to be honest I did notice an overcharge one day about 15v then it went to 13.2-13.6v the next day. So most likely my alt is failing is what your saying correct?
RE: Not fully charging batteries - Bengy88 - 10-15-2022
You need to make sure the batteries in the apu arent AGM. This is a common ussue that goes unseen and alot of times unknown. When an apu is installed 90% of the time agm batteries are installed but the standard flooded batteries are left in the truck. If the batteries for the apu are tied to the batteries in the truck in any way then the batteries are working against each other (i guess thats the best way to put it) agm batteries hold about .3 to .4 volts over a standard battery...... But thats not your problem
But with what your saying about voltage spiking then dropping i would be checking my alternator output versus voltage at batteries
RE: Not fully charging batteries - bwake - 10-20-2022
While you are in the process of checking the alt and voltage drop to the batteries, check to see how much a/c voltage (a/c ripple) is making its way past the alt diode pack and to the batteries. I've recently run into several trucks that had cheap alts put on them and allowing too much a/c voltage to the batteries. This will not only take out the batteries in a quick fashion, it will cause all sorts of electrical gremlins to show up. Anything close to or over 100mV needs to have a new alt installed.
RE: Not fully charging batteries - Trey7981 - 12-08-2022
Fixed. Coolant got in the altenator. I replaced it and we are fully charging again.