Weird Battery Charging issue

[tumbleweedsbns]

Strange Electrical Issue.

BLUF. My Alternator isn’t charging my battery to 14V. I’m getting a constant 12.6V. But when I decelerate it jumps to 14V like normal. When I finally stop or accelerate, the voltage drops back to 12.6V.

Everything was running well. Just completed a 12-hour long drive. Heading up a HWY to a trail, I hit a pothole what would swallow a motorcycle. Surprisingly it didn’t set off my airbag the bump was that hard. I didn’t notice anything immediately, but when I got to the trail I noticed the alternator wasn’t putting out 14.1 – 14.2 volts. I was getting a steady 12.6V. I put the battery on a charger when I got back from the trail and ensured I was topped off before making the 12-hour drive home. After getting home the from the trail (it was dark so I had to run headlights) the battery was 75%. After the 12-hour drive home, the battery was ~85%

On the way home I noticed something peculiar. I’m getting a consistent 12.6V at idle, at highway speed, higher RPMs while in park/neutral. But when I decelerate, either braking or coasting to a stop, the voltage jumps to 14.1, 14.2V like normal. As soon as I coast or brake to a stop the voltage drops back down to 12.6. If I need to accelerate after coasting or braking, the voltage also drops. Weird huh?

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[azjl#3]

13.2 is where mine sits charged up while driving, I think thats right at spec.

 

[alphawolff]

Strange Electrical Issue.

BLUF. My Alternator isn’t charging my battery to 14V. I’m getting a constant 12.6V. But when I decelerate it jumps to 14V like normal. When I finally stop or accelerate, the voltage drops back to 12.6V.

Everything was running well. Just completed a 12-hour long drive. Heading up a HWY to a trail, I hit a pothole what would swallow a motorcycle. Surprisingly it didn’t set off my airbag the bump was that hard. I didn’t notice anything immediately, but when I got to the trail I noticed the alternator wasn’t putting out 14.1 – 14.2 volts. I was getting a steady 12.6V. I put the battery on a charger when I got back from the trail and ensured I was topped off before making the 12-hour drive home. After getting home the from the trail (it was dark so I had to run headlights) the battery was 75%. After the 12-hour drive home, the battery was ~85%

On the way home I noticed something peculiar. I’m getting a consistent 12.6V at idle, at highway speed, higher RPMs while in park/neutral. But when I decelerate, either braking or coasting to a stop, the voltage jumps to 14.1, 14.2V like normal. As soon as I coast or brake to a stop the voltage drops back down to 12.6. If I need to accelerate after coasting or braking, the voltage also drops. Weird huh?

Vehicle can and will charge at 12.6V all day long. If you have a charging issue you would have a red battery light illuminated in the dash. You can verify this with a scan tool and compare voltage sense to target charging voltage under PCM data.

 

[tumbleweedsbns]

Vehicle can and will charge at 12.6V all day long. If you have a charging issue you would have a red battery light illuminated in the dash. You can verify this with a scan tool and compare voltage sense to target charging voltage under PCM dat

 

[tumbleweedsbns]

I 'had' a red battery light. The following day I tightened the battery terminals. Initially that seemed to help and I got 14.1V. Then it went back to 12.6V. Then the following day I searched more for loose wires, perhaps a bad ground. Didn't find anything, but now it is charging at 13.9-14.2V just like before. The batteries are now at 100% SOC and 100 & 98$ SOH (I have two batteries with the Genesis system). My assumption now is that the loose battery terminals were the issue. It just took a while for the ECM to catch up.

My next plan is to upgrade to a 'Big 7 Wire' to ensure I have good connections and grounds.

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