jakwi
Petty Officer 2nd Class
- Joined
- Jan 7, 2019
- Messages
- 184
I have a strange issue that I'm hoping someone can shed some light on.
I have a 2003 Bayliner 245 with a 357Alpha4v Mercruiser, which is just a 350 reman.
The battery charger quit earlier in the year, but since I take it out almost every weekend it hasn't been an issue. It has two interstate batteries new as of about 2 years ago, so not really new now, but I kept them on the charger until it quit.
I was prepping it to take it out yesterday and It didn't want to start, coughing and spitting, sort of half running, but terrible. It would spin over just fine, but it was like it was missing on half of the cylinders. I checked a few things out. voltage was at 11.5 at the coil, which is a little low. I had the switch set for both batteries. I checked the voltage on each battery independently. and Bat 2 was a little lower than bat one. 11.5 vs 12.25 So I switched it to batt one only and it fired right up and ran great. I checked my charging voltage and it was at 14.2, so charging system was working fine.
While it was running I switched it back to both batteries, so that it would charge batt 2, but it immediately went back to running really poorly. I found this strange because at 11.5 it seems like batt 2 is just a little undercharged, I thought the charging system would bring it right back up. I also found it strange that there was enough voltage to spin the starter with no issues, but not enough to run the ignition system. Is the Thunderbolt 4 that sensitive to battery level?
Anyway we had a great day using bat 1, but I'm not sure what to do about batt 2. I put it on a battery charger with a desulfator, and I put a trickle charger on bat one, I need to get a replacement two bank charger, it's on the list. The easy answer is just to replace it, and probably that's what will happen, but I'm hoping the desulfator will bring it back. 2 years doesn't seem like much time for a battery to go bad, and I'd really like to understand why a mildly flat battery will keep an engine from running when the charging system is working fine.
Thanks
I have a 2003 Bayliner 245 with a 357Alpha4v Mercruiser, which is just a 350 reman.
The battery charger quit earlier in the year, but since I take it out almost every weekend it hasn't been an issue. It has two interstate batteries new as of about 2 years ago, so not really new now, but I kept them on the charger until it quit.
I was prepping it to take it out yesterday and It didn't want to start, coughing and spitting, sort of half running, but terrible. It would spin over just fine, but it was like it was missing on half of the cylinders. I checked a few things out. voltage was at 11.5 at the coil, which is a little low. I had the switch set for both batteries. I checked the voltage on each battery independently. and Bat 2 was a little lower than bat one. 11.5 vs 12.25 So I switched it to batt one only and it fired right up and ran great. I checked my charging voltage and it was at 14.2, so charging system was working fine.
While it was running I switched it back to both batteries, so that it would charge batt 2, but it immediately went back to running really poorly. I found this strange because at 11.5 it seems like batt 2 is just a little undercharged, I thought the charging system would bring it right back up. I also found it strange that there was enough voltage to spin the starter with no issues, but not enough to run the ignition system. Is the Thunderbolt 4 that sensitive to battery level?
Anyway we had a great day using bat 1, but I'm not sure what to do about batt 2. I put it on a battery charger with a desulfator, and I put a trickle charger on bat one, I need to get a replacement two bank charger, it's on the list. The easy answer is just to replace it, and probably that's what will happen, but I'm hoping the desulfator will bring it back. 2 years doesn't seem like much time for a battery to go bad, and I'd really like to understand why a mildly flat battery will keep an engine from running when the charging system is working fine.
Thanks
