volvo low voltage alarm

Discussion in 'Trucks [ Eighteen Wheelers ]' started by chrisbecker, Mar 6, 2012.

  1. chrisbecker

    chrisbecker Bobtail Member

    Messages:
    19
    Thanks Received:
    3
    Joined:
    Mar 6, 2012
    Location:
    Faribault,MN
    Does anybody know if the low voltage alarm can be adjusted? I own a 2010 730 that I bought new and this thing has been a pain since day one. when i shut the truck off the batteries are at 12.6v and when it hits 12.4v it alarms out and shuts off most electrical items. What Im figuring out is that its not that the batteries are getting drained its more of an issue of things turning on and off and causing the initial power draw dropping the voltage too low. My dealer tells me that Volvo wont let them change it. I honestly dont care what Volvo wants I own the truck and I want it changed but dont have the tools or knowledge to do it.:biggrin_25512:
     
  2. Icee

    Icee Light Load Member

    Messages:
    228
    Thanks Received:
    117
    Joined:
    Apr 28, 2011
    Location:
    Finland

    Can't comment on lower the Voltage alarm but 12,6v when just shut down is not healthy. Should be close to 14v, maybe one cell on the batteries are dead.
     
  3. vangtransport

    vangtransport Medium Load Member

    Messages:
    459
    Thanks Received:
    179
    Joined:
    Apr 14, 2009
    Agree with Icee!! Something isn't right with your charging system. I have the same setup in mine and also had the same problem. 1 bad battery will cause the whole 4 battery chain to sound the alarm. I had to replace all 4 Volvo batteries, then replaced 4 batteries from Petro because they were not tight enough in the holder so they were bouncing around. IMO, if you bypass that alarm you might not be able to start it later. I went threw the whole system and cleaned and protected every connection with stuff from NAPA & installed NAPA batteries, it worked like a charm.
     
  4. vangtransport

    vangtransport Medium Load Member

    Messages:
    459
    Thanks Received:
    179
    Joined:
    Apr 14, 2009
    BTW, are you getting any fault codes under vehicle ECU? If you get a data link error I would go threw the whole system, clean & protect. I also ran a separate copper ground wire. I noticed when I plugged in, I would have this problem the next trip, I think the Inverter/charger cooked 1 of my batteries. Since running the separate ground and doing the NAPA stuff, I haven't had the problem.
     
  5. chrisbecker

    chrisbecker Bobtail Member

    Messages:
    19
    Thanks Received:
    3
    Joined:
    Mar 6, 2012
    Location:
    Faribault,MN
    I have 4 950 CCA Napa batteries that I put in new 6 months ago. I called napa today and they told me that just after shutting the truck off they should be at 12.565v mine are at 12.6. I have dealt with bad batteries before and corrosion issues so I scrubbed all connections, bolted everything tight and sprayed napa terminal coating all over every exposed surface...... I have no fault codes no errors.......
     
  6. Hardlyevr

    Hardlyevr Road Train Member

    Messages:
    3,165
    Thanks Received:
    2,386
    Joined:
    Jul 30, 2009
    Location:
    Gardners,PA
    The low voltage senses not only battery level but the drain/rate on them. What all are you running with the key off? Reducing what is on, espcially in the interior lighting will keep the alarm off.
     
  7. chrisbecker

    chrisbecker Bobtail Member

    Messages:
    19
    Thanks Received:
    3
    Joined:
    Mar 6, 2012
    Location:
    Faribault,MN
    If I turn everthing off and just run the webasto that will last about 6-8 hours. Running the fridge and main interior light maybe an hour. But what confuses me is when I go home and leave the fridge running for the weekend it will only drain the batteries from 12.6 to 12.5. The batteries are strong but the system is just set too sensitive.
     
  8. Kansas

    Kansas Road Train Member

    Messages:
    2,540
    Thanks Received:
    2,528
    Joined:
    Apr 14, 2009
    Location:
    aircap, Ks.

    Ummmm no, thats not true. 12.6 is totally normal when the engine is off.

    When the engine is running and the alternator is charging voltage should be near or at 14volt.
     
  9. Icee

    Icee Light Load Member

    Messages:
    228
    Thanks Received:
    117
    Joined:
    Apr 28, 2011
    Location:
    Finland
    Take a volt meter, chose a car, truck what ever you want. I can ensure you it will show a good bit over 13v.

    It's 24v system here but when just shut down it will show 28v, after 8h with webasto + fridge will be down to 25-26 if the batteries are healthy...


    12,6 is to low, measure every battery individual to see witch seems to be bad. Even a brand new one can have a dead cell.
     
  10. Hardlyevr

    Hardlyevr Road Train Member

    Messages:
    3,165
    Thanks Received:
    2,386
    Joined:
    Jul 30, 2009
    Location:
    Gardners,PA
    I think I'll join the bad battery bandwagon, when you 1st shut the truck off, you ought to have voltage over 13.