-
Booster Terminals
Does anyone know if the booster terminals in the engine compartment are for 12 volt or 24 volt battery boost? Can you use booster cables to jump off the engine with a 12 volt automoblie or 12 volt battery charger? Went to crank the coach today and the batteries were low. Checked them with a volt meter and they were at 10.5 volts, not enough to crank the bus. Gonna put a charge on them but was just curious about the booster terminals in case I needed to use them. Thanks!
-
17 Replies
-
seated coach(original) curb side door should be 24 volt. ck see if you don’t have around 18-22 there now… Also you prob need around 11.5 for your DDEC to work any way… If you get it spinning the alternator will pick the DDEC voltage up quick enough to work. Good luck…
-
24 Volt
-
Wondered about this also. On door panel inside compartment schematic shows 12 and 24 volt for batteries in how they are wired. Hadn’t put the meter to um but would be interested to know if you could put charger on 12 volt side and charge batteries or jump.
-
No.
You can always charge up the batteries with a 12 volt charger, but you have to isolate the batteries to do that. You just cannot jump start the coach with 12 volts. You need 24 volts for the starter.
The reason you have a cutoff for the 12 volt is that is primarily to provide power to the DDEC module. If I remember correctly you can actually start and run the bus with the 12 volt master switch off, but after a while the 12 volt part of the system will be discharged and the DDEC will shut down. The equalizer will not be able to charge the 12 volt side with the switch off if I recall correctly.
-
I must have a problem in some other place. After putting the batteries on a charge for a few hours they were at 12.5 volts when I flipped the master switch I had 25 volts at the starter and booster terminals. All I get when I turn the key is a quarter turn of the engine. First time I ever had this problem and so frustrating to try and figure out where the problem is. Normally it makes two revolutions and fires up. What are some options to maintain the coach batteries charge?
-
1st prob bad ground—-loose or dirty connection + or – 2nd one bad battery—-you might be only showing a surface charge and when under load one fails… Break connection of batteries in stack then ck voltage indivually. . Have found the most likely to fail driverside top stack.
-
It is important to check the battery voltage under load ……….especially starting batteries.
On more than one occasion I’ve seen starting batteries check out “ok” with a voltmeter with no load, then drop like a rock when the starter was engaged.
If it were me, I would check the voltage while starting the bus before looking elsewhere.
-
For your batteries to function you need to bring them up to float. You will go through bulk voltage, acceptance and then float voltages. Your ending charge voltage is going to be around 13.2. Then you need to test the batteries to make sure they do not have issues. After fully charging them individually let them rest for a day or so and if they are all showing around 12.7 to 12.8 volts it is likely they are OK, but only testing will verify their condition. All it takes is for one bad battery to suck the power out of the others. This applies to the house as well as chassis batteries.
If they were dead or near dead and they were charged to 12.5 when you tried to spin it over it is likely they aren’t sufficiently charged to handle the starting load required.
But heed Bob’s advice also while waiting for them to charge and rest after charging so you can check them, make sure your connections are corrosion free, not only at the batteries, but at the chassis connections. You can always get good voltage readings when there is little or no load, but with a load bad connections will create a large voltage drop.
Finally, and one of the most common issues I get in phone calls about is to check the battery cables to make certain they are connected properly so you get the 12/24 volt system as Prevost intended. Every cable needs to be hooked in the right place and you need to be certain the small DDEC wires are also in place. After you have checked them, go check them again. Did I mention to check the cables to make sure the batteries are connected properly?
-
Jon /others do a much better job of communicating than I do. Thank goodness for the help!! for me.. In a perfect world we would never have corrision or bad connections—-one weak link(batt cell) all loads would be equal( devices are in place to help this) all that is perfect!! world.. And yes I would spell better…I only point out most likely points to start from–then step 2 etc……
-
Don’t worry about it Bob. This is not a Spelling or English test and we know exactly what you are saying.
-
The Saga continues! No corrosion, tight connections. After hours of charging batteries seperately they will only charge up to 10.5 volts. Conclusion, got to replace batteries! Had them replaced 3 years ago at a high dollar western star dealership. Premium price, cheap batteries! Lesson1 – only buy good grade batteries in the future!
-
Have a hard time believing they all failed equal– same time etc..fwiw.. Batt have a date of manfacture code like tires I don’t buy over 3month old ..they age as soon as they are made.. not when they are installed. Bob
-
Mike,
Take your PC Napa discount card, you do have one right, and get your group 31 batteries at good ole Napa.
-
Tom and Bob, Thanks for the good advice …… will do!
-
Tom
is there a list of NAPA’s that take the Napa card? All the one’s in my area don’t honor it or they want to fill out a credit application.
Log in to reply.