| Author | Message | ||
| Camill Paul Elbisser (Paul)
Rating: N/A |
Fellow Bus Nuts The 24 volt batteries on our 102A3 keep going down with the battery switch off. (about6 to 8 weeks) I have been told that the Battery Equalizer is putting a drain on them. I have removed the wires on the Equalizer from the set of batteries to see if this will help. Removing the ground first then the 12 & 24 volt taps. ("by DA Book") Thinking about this can I put a switch in the Ground tap wire to remove equalizer from service, leaving the 12 & 24 volt taps on the batteries. Will this open the circuit to stop the drain on the batteries from the equalizer. There is two wires on the 12 volt tap on equalizer. One wire to batteries (12 volt center tap) other goes to 40 amp. breaker and on into coach. Adding a switch after the breaker to stop all 12 volt draw from batteries. This way you could not power equalizer in wrong order Is this right Thank you Paul | ||
| Jon W. Rating: N/A |
Assuming all corrosion has been cleaned from the terminals and surfaces of the batteries, my guess would be to consider one of the batteries is bad. In a short time this could be confirmed by separating the batteries electrically and removing the ground so they have no possibility of draining. Check their voltage individually every 24 hours. If one is bad it will stand out because its voltage will drop before the others. | ||
| Ed Jewett (Kristinsgrandpa)
Rating: N/A |
Paul, I don't know what your book says, but the book that came with my coach says NOT to unhook the 24V and leave the 12V hooked up, it can blow the equalizer. Keep this in mind when installing the switch. If you cut the power to the equalizer first all should be fine. Maybe its just the brand of equalizer I have, its a Vanner. In the 3 years I've had my coach I've unhooked the batteries numerous times, without knowing this,(till last week) and luckily didn't blow anything. My 12V wires are on top of the 24V wires and when I pulled them the 12V came off first. I planned to do the same thing, just haven't gotten that far yet. I would check the book to see what is says. HTH ED. | ||
| Ed Jewett (Kristinsgrandpa)
Rating: N/A |
I for got one thing, use a DC rated switch. DC arcs more and eats up the contacts faster. ED | ||
| Buswarrior (Buswarrior)
Rating: N/A |
Hello Paul. The Equalizer should not be pulling the batteries down. I left mine for a couple of months last year, equalizer connected, battery switch pulled. No problems. I would put my efforts into a search for the real problem. happy coaching! buswarrior | ||
| TomNPat
Rating: N/A |
Buswarrior, Our vanner is doing the same thing. Will draw the batteries down in a little over a week. Disconnect it and they're still good after two weeks. When removing the positive lead to the vanner from battery #2 (with the 24 volt switch off) I get an arc. That, on other vehicles, indicates a draw on that battery. So what is our 'real problem'? TomNPat | ||
| TomNPat
Rating: N/A |
Buswarrior, Another thought on the 'real problem! Is it possible that a difference in battery condition, one good, one bad, would cause this draw? Haven't tried disconnecting the batteries from each other for a test of life. But will be replacing ours in May. Could try it then. TomNPat | ||
| John MC9 Rating: N/A |
Before replacing batteries used in the 24v series array, take some time to charge and test each battery individually. If you don't start with each battery fully charged, the slightly discharged battery will never recover. | ||
| Camill Paul Elbisser (Paul)
Rating: N/A |
Thanks for all the input The only 12 volt I know on the bus is the center tap for head lights. The book tels me there is a CB receptacle, but I can not find it. I will separate the batteries and record voltage daily for a week or two. Batteries new April 2005 Paul www.incredibus.com | ||
| FAST FRED Rating: N/A |
New batterys loose about 1% per day in normal (77F) temps. Old or abused (run dead is abuse) batts will loose 3% or more at the end of their usefull lives. Perhaps the loss in just internal, and all you need is a fresh set of Starts? FAST FRED | ||
| Sojourner (Jjimage)
Rating: N/A |
Load test each battery with 100amp battery tester after fully charge. If it tested bad then replace it. But if good then read on. Anything connected is “on” or corroded power switch or alternator’s diodes or Battery Equalizer or any electronic devices with build-in diode are alive or direct connection with main power from master cutoff switch or direct from battery source. Diode will in time to be defective or damage from over heated to cause current draining (leaking) or short-circuit the battery load source. Leaking diode alternator wills still charge but less output & hotter temp. Another popular problem is something is left turn-on such as baggage’s lamp or whatever. If battery is acid coated, brush on half cup of Baking Soda & water will neutralize & remove acid coated surface. Then rinse with fresh water. Caution leaves caps on to prevent soda into battery’s cell. To test for battery drainage….purchase 2 (12v) test lamp with probe. Disconnect either one of two battery cable & connect in series both test lamp in-between disconnects. If lamp not burning then reduce to one test lamp. If it not burning then either none or very small drainage that it will take weeks to run battery down enough to give cranking problem. If everything is shut off except any direct connect to diode & result of more than 250ma current drainage….bad diode or acid coated battery to metal frame. Volt/Amp meter would work with setting @ 24v or higher…..if barely read….reset @ lower volt….if it still barely or no volt mean drainage is very good…other word problem elsewhere. If drainage is “point” .5 volt or less…it consider normal. Suggestion & inexpensive; Incorporate 2 red lens & bulbs (12v 3 watts (250 ma) or less) with socket in series between input & output thermals post of master cutoff switch. Mount sockets near master switch and or dash panel. Whenever it light up after master shut-off, will indicate you have above normal battery’s drainage. Then you will want to save unnecessary aggravation while on trip. So do the number one easy rule, is to always turn master switch off whenever parking while engine shut down. Good habit is to follow so you won’t forget later, even if you gone to the grocery store for few minutes. FWIW Sojourn for Christ, Jerry | ||
| Buswarrior (Buswarrior)
Rating: N/A |
Hello. I'd call an equalizer that drains batteries defective. I would be afraid of what it might be doing to the batteries. I have not seen a stock coach or transit install where the equalizer is switched. Wired in direct past the main shut off. The schematic on the vanner shows to do it that way, IIRC. I'd be thinking there is no way a coach being sent in the winter to Vermont or Colorado skiing would be equipped with something that draws down the batteries that you can't shut off! Every coach and transit you see on the road today has an equalizer in it, and have had them for getting close to 20 years. There should be someone in your neighbourhood who knows how to test and repair them. There should also be a healthy supply of good used take-outs at your local transit graveyard. If you are lucky, they don't know what it is! happy coaching! buswarrior | ||
| BUSFOOL (Chuck)
Rating: N/A |
I am have a similar problem with my mc9 , purchased new batteries and still have the same problem . I am going to a welding machine repair shop and getting the knife switches out of an old welder . I am going to build it into the battery box so when I close the switch it will cut all the power .I know this will not find the voltage leak but I will not have to worry about starts again.If you ever discover what the problem is let us know | ||
| H3-40 Rating: N/A |
A little off topic but similarities of the such. Our H3 has two switches for the batteries. One is for 12v and one is for 24v systems. It says in our book to ALWAYS turn both of these switches to the OFF position when stopping the coach for any small length of time as in stopping for dinner. Ok after a few battery replacements due to owner forgetfullness, I now turn the battery switches off religously. Only thing is, there is still power supplied to the wire harness, relays and breakers in the front part of the coach. Beats me as to why but I always thought that when you turn the main disconnect OFF, it shuts everything off but I guess in this case, maybe it doesn't! Ace | ||
| Marc Bourget Rating: N/A |
No Ace, it's the dielectric from the aluminum black tank that's generating the extra electricty! (Not!) You can find out exactly where the drain occurs by proper use of an Digital VOM and amp-meter simply by following the advice contained in the archives. Read the archives rather than reacting! Marc Bourget | ||
| H3-40 Rating: N/A |
FYI there isn't one question in my previous post that says I'm looking for an answer, so why must I look in the archives? Why must you reply? As long as I do what the book from Prevost recommends, the coach is fine, the batteries are fine! It's documented from Prevost to ALWAYS turn the batteries OFF, so there must be a reason that "they" know about. I don't need to know why. They built it, I didn't! If your wanting to look thru the archives, go for it. Maybe you can go back and refresh your memory about tanks while your at it because you never seem to leave anything alone! Ace... the one with the 1 1/2 year old aluminum Peterbuilt fuel tank used for black water waste that everyone said it shouldn't be done, that was done and works great, with NO leaks! | ||
| John MC9 Rating: N/A |
Oh man. Ace, I started that "tank debacle", no tanks to anyone else... And... I never said you shouldn't have mounted them the way you did. I said that others must be careful in the manner they hang water tanks, since it's very easy to forget how much water weighs. A full 80 gallon tank will weigh nearly 800 lbs! If it's being suspended from the plywood alone, or the total weight isn't properly distributed, it can get quite stinky. You did a great job hanging yours, Ace. But it shouldn't be recommended as an off-hand comment to a newbie, that it's perfectly fine to hang the water/waste tanks from the bay ceiling, without pointing out the need to secure them properly due to the weight involved. It wasn't a strike against you, man. At the time I typed it, I did so to help clarify the importance. Jeesh... I thought we put all that behind us? (Hey I@n, where's that "feelings" button?) | ||
| John MC9 Rating: N/A |
Camill - Both the local bus garage, and the guy I bought my bus from, had told me that the equalizers are more trouble than they're worth. They both claimed that battery failures were common when an equalizer was used. I found that the bus alternator draws a bit of juice while the bus is off. If the bus is expected to sit for more than a few days, I'll switch the disconnect to off. But there shouldn't be any problem leaving the batteries connected while the bus sits for a day or two (or four or five), and I wouldn't bother disconnecting them if I'm stopping for an hour for lunch.... If the batteries are draining down that fast, you have a problem that should be located and resolved. Rather than an equalizer (or a center tap), my choice would be a dc to dc converter. Cool Power Dc To Dc Converter | ||
| Jon W. Rating: N/A |
My bus with equalizers has sat without running for as long as three months with the 12 volt (DDEC III computer) and 24 volt (bus) switches on and fired right up as soon as I hit the key. If your batteries are dying you have something pulling them down like a key "off" accessory or dirty terminals. On a previous coach I traced a problem with depleted batteries to a Racor heater just to give an example of how totally unexpected items could be the culprit. | ||
| Marc Bourget Rating: N/A |
Ace said: "Beats me as to why . ." I considered that an implied question. If you didn't really care, why was it mentioned? Your mention prompted my comment regarding diagnosis accessories. Maybe not now. I certainly wasn't "ordering" you to take care of it. I was really trying to plant a seed (of thought). Some time, some place you'll get distracted, forget to turn on the charger and the batts will go flat. Then you'll decide searching for the cause is worth your while. This BB is supposed to be about helping. Jon W. And, sir, didn't you use accessories like a DVOM and/or an amp-meter in determining that cause? Onward and Upward | ||
| Richard Bowyer (Drivingmisslazy)
Rating: N/A |
I had a strange problem once with my batteries being drained after a few weeks. I finally traced it to a 12 volt electric clock I had installed. The clocks second hand actually ticked from second to second. With an amp meter in series I discovered that there was a substantial inrush of current every time the clock ticked. BTW, I think that clock is still installed in the dash of DML, so whoever owns her now should not reconnect it. LOL Richard | ||
| T. (Bluegrass)
Rating: N/A |
Sounds like a good place for a Contentious duty solenoid, to everything but the starter, this would let every thing to run through the solenoid until you have a chance to run It down. Tony | ||
| Jon W. Rating: N/A |
Marc, At the time I did not. Now that I have treated myself to all sorts of tools I would do that. It turned out easy to trace because I just started looking at circuits that were "hot" (house excluded) with the key off. When I found it I was lucky because it was installed by the previous owner, not Prevost or the converter, and it went through a thermostat. When I did my checking it was cold enough to be drawing current. Don't laugh, but I knew the problem was solved when I could remove or install a battery terminal in a relatively dark garage (OK, it was a barn) and not see any spark whatsoever. | ||
| Marc Bourget Rating: N/A |
Jon, I guess it was "digital" cause you were removing the terminal by hand! ROFL!!! And I'm not laughing at you, just the opportunity you provided me to make a joke out of the "digital" connection. | ||
| Jon W. Rating: N/A |
Good one. Having had to do without for so long, I still find myself doing things in the most basic ways possible. I know a computer can find a bad plug wire on my car, but I also know a water spray mist on my plug wires individually with the car idling will also find the wire that is causing my car to miss. Still learning. | ||
| Gary Stadler (Boogiethecat)
Rating: N/A |
Heck it's more fun to just pull the plug wires one by one as the car is idling... when you find the one that doesn't make a change in the engine roughness, you've found the bad one- and if you're real lucky you'll get shocked!  About the battery drain stuff, My mom is extremely happy with that automatic diconnect doodah I bought her ( www.prioritystart.com ) so far no more dead batteries. It really works!! | ||
| Jon W. Rating: N/A |
If I pulled plug wires I would end up like the TAZAR test dummy. |