Riverpark Eric Posted May 4, 2011 Share Posted May 4, 2011 I've had my Odyssey a few weeks, and about 3 or 4 times, the battery wouldn't start the engine after sitting overnight. It's a brand new battery and has a powerful charge, but when it's drained, it's d r a i n e d. Upon inspection with my neighbor (an electrical engineer, but by no means a MH expert), we figured it must be the alternator. Stuck our heads in the engine, and guess what, there's a brand new alternator with a new belt. Looks like the previous owner had thought the same thing we did! Hooked up to a charger, it spikes like crazy, leading me to believe something is grounded that shouldn't be. Right? The coach battery is fine. It's an old WalMart car battery, but that thing keeps ticking. The big bummer is that tomorrow was to be our maiden voyage. Any quick advice to salvage the situation, or should I take it to a mechanic who can isolate it and diagnose the problem? Thanks, Eric in Sacramento Quote Link to comment Share on other sites More sharing options...
Alvin Posted May 4, 2011 Share Posted May 4, 2011 I know you said the battery is new or newish, but my experience and knowledge tells me that you should do some testing using a 2nd new battery. I have actually seen bad batteries shortly after purchase, and also after only one winter season of use. A bad battery can actually read 13 volts but have such a high internal resistance that it is useless for starting.... and it's always harder to start it after leaving the vehicle overnight. Please see this post from several months ago: http://toyotamotorhome.org/forums/index.php?showtopic=3332&st=0&p=17906&hl=+alvin%20+battery&fromsearch=1entry17906 I still hold to my guns about buying (or at least testing) with a 2nd battery. It's only about $100 or less... and (SO FAR) every time I've thought it could be something else, it has turned out that a new battery did the trick, even when I thought I had a good battery for sure. I'm also an electrical engineer by trade with limited automotive experience (but if you want to shoot your Ethernet router out of a bazooka I'm the guy you want.... I design and ruggedize advanced Ethernet systems for military aeronautical applications); I recommend you do the easy thing first; another new battery (or test with some truck battery you can swap in). Cold temperatures can hose a marginal battery too. Does it start later in the day after the sun has been shining on your vehicle? Then replace the battery. Try this test to eliminate your vehicle issues: Run the motor and charge your battery up as much as you want. 2) turn off your motor, and completely disconnect both battery terminals, but leave the battery out in the cold with the vehicle. 3) Go away overnight... since the battery is complete disconnected, it can't possibly be draining anything from the vehicle while you sleep. 4) In the morning, re-connect the battery. Does it still not start? Then your vehicle is fine, and it's the battery; replace it. If the vehicle started up great, then as long as you are satisfied it wasn't something else (like a warm summer night) then maybe you have a vehicle problem. If the vehicle barely starts, I still put my money on replacing the battery. Good luck. Quote Link to comment Share on other sites More sharing options...
Maineah Posted May 4, 2011 Share Posted May 4, 2011 Sounds like some thing is staying on. The isolator will keep the coach battery from draining disconnect the cable from the truck battery and touch it to the post with every thing you know of off and see if it makes a little spark better yet connect a test light to the post and the other end to the cable if it lights there is some thing drawing current. Check by removing fuses until the light goes out and then track down the source, the radio will draw a little bit of power for the memory and it may or may not light the test light if it does it probably will not be very bright. Quote Link to comment Share on other sites More sharing options...
Derek up North Posted May 4, 2011 Share Posted May 4, 2011 I'd try another battery in there, too. Will the coach battery fit? As Alvin said, new doesn't necessarily mean good. Quote Link to comment Share on other sites More sharing options...
waiter Posted May 4, 2011 Share Posted May 4, 2011 Put a voltmeter on the battery with truck running. Should read > 13.5 volts. (14.0 - 14.7) If its below 12.5, the alternator is not charging. Turn the truck off and see what it reads, should be around 12.6 -13.0 Does your ALT light come on when the key is on (truck not running) it should. What kind of isolator do you have, looks like a small can with two big wires and one small wire. OR the kind with fins on it? Its possible to have a fairly new battery with a bad cell. with a bad cell, it will not hold a charge. JOhn MC 88 Dolphin 4 Auto Quote Link to comment Share on other sites More sharing options...
Riverpark Eric Posted May 8, 2011 Author Share Posted May 8, 2011 Turns out it was the starter battery. It was brand new, but had drawn down to nothing, so I took it back to Kragen to check it out. They put it on a one hour charge so they could test it. Throughout this whole process, my neighbor the electrical engineer (and most of you!) were telling me it was the battery. Battery, battery, battery. Kragen told me nope, the battery is good. I took it to a competitor to have them check out, and the manager told me that you absolutely can NOT one-hour charge these gel top batteries (pretty pricey...about $190) and that they'd ruined it by doing so. One thing let to another and I ended up getting Kragen to replace battery for free. Lesson learned. We ended up going up to Collins Lake (Northern CA) and had a GREAT time on our maiden voyage. Everything worked well (the cab a/c needs to be recharged thought) and we're looking forward to our next trip. Quote Link to comment Share on other sites More sharing options...
Ron 'n Sue Posted May 14, 2011 Share Posted May 14, 2011 Turns out it was the starter battery. It was brand new, but had drawn down to nothing, so I took it back to Kragen to check it out. They put it on a one hour charge so they could test it. Throughout this whole process, my neighbor the electrical engineer (and most of you!) were telling me it was the battery. Battery, battery, battery. Kragen told me nope, the battery is good. I took it to a competitor to have them check out, and the manager told me that you absolutely can NOT one-hour charge these gel top batteries (pretty pricey...about $190) and that they'd ruined it by doing so. One thing let to another and I ended up getting Kragen to replace battery for free. Lesson learned. We ended up going up to Collins Lake (Northern CA) and had a GREAT time on our maiden voyage. Everything worked well (the cab a/c needs to be recharged thought) and we're looking forward to our next trip. ++++++++++++++++++++++++++++++++++++ Glad to hear you got that problem solved! Now you're up and running, why not come up to the Toy-In on Vancouver Island June 24 - 26? We have a great spot all picked out for you! We'd love to see you! Click on: http://www.livingforest.com/ or http://www.campingbc.com/ Ron 'n Sue Warrior Quote Link to comment Share on other sites More sharing options...
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