Chassis Battery Charging

[rahangman]

Although I seem to have most of my "Phantom" drains off my Chassis Batteries, I have a small 24vdc charger (Battery Tender) installed. It is hooked up correctly and is doing a great job. That being said, I have not as of yet hardwired it to the bus, and just plug it into an extension cord if I am parked for any period of time. I have been told that to connect to the small box that provides for my Block heater is the easiest way to do so. But, that would cause me to have power to my block heater all the time which I don't think I want. I would prefer to have a way to control the power for both the BH and Charger from the cockpit. Any thoughts without a real major "project";)

[Kenneth Brewer]

Although I seem to have most of my "Phantom" drains off my Chassis Batteries, I have a small 24vdc charger (Battery Tender) installed. It is hooked up correctly and is doing a great job. That being said, I have not as of yet hardwired it to the bus, and just plug it into an extension cord if I am parked for any period of time. I have been told that to connect to the small box that provides for my Block heater is the easiest way to do so. But, that would cause me to have power to my block heater all the time which I don't think I want. I would prefer to have a way to control the power for both the BH and Charger from the cockpit. Any thoughts without a real major "project";)

Well, the BH (and the charger) would only be powered if you were plugged in or running the genset.. If you don't mind an either/or situation, you could put in a DPDT switch that would be manually switched in the compartment you choose outside, if you cannot reasonably/practically put it inside somewhere. That's one way that would not require finding spares or fishing wire through, presuming a/the breaker is appropriate for either.

[truk4u]

Roger,

Some of the early buses did not have the block heater hard wired, it was just a plug that was behind the door where you fill the oil reservoir and could be unplugged from the 120v receptacle. If that's the case, just plug your charger into that receptacle and control it with whatever set up CC used to turn on the block heater, either a button or a breaker in the 120v panel. If you need the block heater, just reverse the process and then change it back.

If the block heater is hard wired, you could put in a switch like Ken suggested.

[rahangman]

Thanx for both of those ideas. I will have to wait till Thursday to get to the bus, it is in Joplin getting a Radiator Re-coring. Will let you all know how I go.

[Jon Wehrenberg]

Ken and Truk both gave good advice. What concerns me is the fact there may be phantom loads. Actually and more precisely phantom loads that do not go away when the main switches for the chassis are turned off.

A good set of batteries needs no charging for at a minimum 2 months. If with the main switches off there are still battery loads I would be all over that coach until I found them because it is probable they are not provided with circuit protection. Rather than relying on a small chanrger to maintain batteries, I would instead recommend a permanent installation of a good three stage charger such as the Guest charger that not only can be used to maintain the batteries, but can also be used to give them a three stage charge if and when they need it. And I would only power the charger after a couple of months to top off the batteries.

The real question is what are the phantom loads.

[LA-HODAG]

Rodger: I think you will find that there is a single 120volt outlet in a weatherproof box in the battery compartment just under the aircleaner and above the webasto, maybe a little forward of the Webasto. The block heater is plugged in there, with the cord extending out through an opening in the cover. At least that's the way my 1990 CC is set up. Power to that outlet is controlled by the switch marked Block Heat on the overhead panel to the left of the driver seat. As noted, it only has power when you are plugged in or gen is running and that switch is on. I like this setup for just the type of use you want. I often use this outlet for patio lights, which are then easily controlled from the dash and don't go through the inverter. Plus, if there was ever a reason to do so, you could plug in the block heater without plugging in the bus. At least where I am located, I seldom use the block heater anyway. It is either plenty warm or we are up skiing and running the webasto for heat, so don't need it. Even for a cold start at home, the Webasto will warm the engine much faster than the block heater. I think the only time I ever used it was once when the Webasto conked out during a ski trip.

Do you throw the chassis battery disconnects when you are parked? I do if parking for over a week. I have not had any problem with my start batteries getting discharged. Maybe that would solve your problem.

Good luck.

[rahangman]

Bryan and all. Just after we bought the bus, Feb 08, had a complete battery failure on first extended trip to Colorado (Spring). Then, 6 months later again in Jax FLA while at Prevost Serv Center where they "talked" me into a new set after they "checked them out" without even removing or completely disconnecting from Bus. Lessen learned. Since then, and some troubleshooting, found a couple loose connections, etc and yes they seem to be staying up pretty good. Then, last summer while at FMCA in Ohio, in 5 days, went dead again. Found bad solenoid in elec compartment under driver seat (with help of Prevost Regional Tech on telephone). Sooooo yup, I am a little paranoid. I use the Battery Disconnect religiously now and find readings drop .1 volt maybe over a 2 day period. Still searching for peace of mind. Yes, I would use the Webasto for a quicker more thorough warm up when cold out. I have not looked into my "outlet" box to determine if it is a plug or hard wired for the Bheater. A friend in Chicago seems to think that I will have to do something a little different with the switch up front due to way it is wired in back for the AC for the BHeater. I hope to find out. My elect education continues. I think 2 sets of batteries inside of a year is enough, although, I have used 2 of the ones that Prevost misdiagnosed on my Home Gen Set for our wonderful Ice Storm Season here in N Arkansas when we are gone in Feb & Mar Thanks again everyone

[Jon Wehrenberg]

Rodger,

That voltage drop is excessive. Something is puilling power from the batteries and it is enough of a draw of current that you should find it.

With the exception of the 3 circuit breakers in the rear electric panel that are for DDEC you should have no loads on the chassis batteries with the key off. At one time there was a discussion from Ben C. that DDEC on occasion would draw power from the chassis batteries with the key off. To rule that out the next time you put the bus away trip CBs #19,20, and 21 (verify they are for your DDEC) along with turning off the 12 and 24V master switches and see if you continue to have the voltage drop. If nothing has changed then at least you can rule out DDEC from doing it.

Be aware that if you disconnect power to DDEC via those breakers you will lose some data, but if you are not having problems that will not matter.

If you are confident you have no phantom loads it is within the realm of possibility you have a battery beginning to fail and you might consider disconnecting the cables and checking each battery individually. As new as they are that is a remote possibility, but doing the check rules out all but additional as yet unidentified phantom loads. It is easy to ignore them and just add a charger, but the reality is if you have something drawing current you need the peace of mind knowing it has circuit protection in the form of a fuse or circuit breaker and will not become a potential fire hazard.

FWIW I had a load on my original coach that took months to find and it turned out to be the heater in the Racor.

[rahangman]

Good advice & information, Jon, I will print this out and give it a go.....one of the reasons I want to "secure" my Chassis batteries, besides the obvious, is, like you say, if stopped for a quick nap or an overnight at any location, and should want to effect a quick departure, having to get out of the coach to energize the batteries, seems a bit....well ..... not good.

[Jon Wehrenberg]

You likely won't have dead batteries during the time it takes to have a nap, but if you have as yet unidentified phantom loads think about this. Those loads are not likely to be fused or pass through circuit breakers. But in the remote chance they are, just imagine that for every foot of wire between the batteries and the fuse or breakers you have unprotected wiring. We have enough potential sources for problems without having as yet unidentified and likely unprotected wires.

One real problem I have with older coaches (mine is one of them) is as time goes on the owners begin to modify them and sometimes those modifications are undocumented and often not of the quality level a converter or professional shop would produce. Kind of scary.

[Woody]

After finding the wiper timer running I thought I had my 24V problem solved but when trying to start yesterday - no luck.

I suspected the batteries as one had failed after after only 4 months last February.

Panterra had installed 4 Autocraft deep cycle marine batteries when I bought the coach in November of '09.

This time a second battery had a dead cell, found this after buying a battery load tester- good investment.

Advanced Auto Parts replaced the first one and gave me 40% on this one.

If I have another failure I will replace all 4 with ???????

[truk4u]

Woody,

Lifeline is the answer! I have been supplying batteries to Poggers since December and everyone has been happy with the cost and service. If your still coming to PSL, we could talk about then.

[Jon Wehrenberg]

Woody,

Truk is not giving you the full correct answer because he likely doesn't want to be perceived as pushing his product. Since I am not selling batteries and have no dog in the fight here is something to be aware of.

Batteries should be changed in sets. Your new battery mixed with older ones is going to create a situation in which none of the batteries are going to perform as required over the long term. Battery manufacturers go so far as to recommend when replacing sets the date codes on the batteries all need to be the same.

Regardless of what you choose to do I would suggest you monitor the batteries in question. My chassis batteries literally go for months without being charged or losing substantial voltage. I recently had a 3 month span between trips, the chassis batteries were not turned off and I still had 25.0 volts at the chassis batteries. If your voltage drops measurably over night or even over a week start looking for phantom loads and try to determine if you have any why they might be pulling down the batteries.

[Woody]

Thanks Jon and Truk, I'll see you at PSL.

[gmcbuffalo]

What do you think of using deep cycle in a engine starting capacity? Those marine batteries may have marginal cold cranking amps to turn over that engine.
Greg

[truk4u]

At 32 degree's, Lifelines start battery is 950 cca vs 750 cca for the deep cycle. You probably can't tell the difference in normal starting operations.

[LNDYCHT]

I personally would not use anything but start batteries for chassis batteries. In a hard start situation starting batteries hold up much longer. Our starting batteries are always being charged when the coach is running. The alternator should have enough capacity to handle all chassis loads, the batteries should act as a buffer for loads and storage for starting. When the coach is not running generally there are no loads on these batteries. Cranking batteries release energy quicker and also accept a charge faster.

I don't know about the U.S. but in Canada cranking batteries are considerably cheaper than deep cycle. I sell around 250 batteries a year, we sell East Penn starting batteries and have had good luck we used to sell Exide and had a lot of returns.

I recently replaced all my 18 month old chassis batteries because of one bad battery. In my experience replacing just one doesn't pay off as when they have been connected together they are really just one big battery.

Just my 2 cents worth

[chtree]

Guys,

I have a real good friend that is interested in a CC Affinity and he asked if the CC service was back up and running. I was hoping you guys had some info I could pass on to him.

Thanks in advance, :-)

Chris

[truk4u]

Chris,

Ron Lee has the facility up and running and they are doing maintenance, repairs and troubleshooting via phone for a fee. It's been a hot topic on the CC Forum and at some point in the future, building new coaches is back in the plan. You can have your friend contact me about the Affinity, the Magna I have is an Affinity without some of the frills.

[travelite]

I'm puzzled why converters don't provide a dash controlled solenoid that joins the house banks with the chassis bank so that everything is kept topped up by the inverter/chargers. Blue Bird has been doing this for years. Recently I was viewing a 2007 coach, I asked the salesman to deploy the slides. He had to first start the engine so that the alternator could supply the load required by the slide-out motors. I questioned this and he said it's by Prevost's recommendation. In this situation, my BB's chargers would kick-in as much as 280 amps to supply the chassis power needs.

[Jon Wehrenberg]

Some conversion do have a means to tie both banks together. While I can see merit in that I can also see some downside. For one, our chassis and house batteries may be of different types. I have lead acid chassis batteries while having AGM house batteries and the charging protocol is different for each.

My inverters are set up for the AGM batteries so I don't have to worry about damaging the chassis batteries or the reverse.

If I had a switch to ties both banks of batteries together, even if for a short time such as to jump start a coach with a bad chassis battery, I would want to have provisions whereby one would not pull the other down. By not joining the two sets I do not have the risk. To compensate for the absence of a means of joining the two sets I have a charger installed by Liberty to charge the chassis batteries. Not the 270 amps worth of charge the alternator can supply but a sufficient charge to restore the current in a reasonable time.

[travelite]

Luckily start lead acid batteries are similar enough to AGMs that compatibility isn't much of an issue, especially if all one is doing is keeping the chassis batteries in float or absorption. Wanderlodge has been wiring them this way for years. True, in bulk charge the lead acid battery isn't being charged optimally, but it isn't any worse than being charged by the alternator, which is basically a dumb charger.

Are Prevost's typically wired so that the alternator can charge the house bank? (Another worthwhile upgrade).

[jack14r]

I really think that the reason for starting the motor would be for the air compressor,I think that the owners manual wants the air up to 110 LBS.before extending or retracting the slides.I have my bus on regulated shop air and never crank it to move the slides in or out,the guest charger seems adequate or the batteries just have enough juice.

[Jon Wehrenberg]

Yes all conversions I have seen use engine driven alternator(s) to charge both house and chanssis batteries.

[travelite]

Jack,

Thanks. I appreciate the reply. Is there an auxilliary compressor on board that can supply the air needs. Starting the S60 to deploy the slide seems unfortunate.

[jack14r]

On my Liberty it is set at about 90 PSI,but they use a Ghast 110 volt compressor that will do 110 PSI. or more they are sold by WW Grainger and others.Some converters use a DC compressor and I had to replace one in my Marathon,my new one struggled to get to 90 PSI.

[travelite]

Yes all conversions I have seen use engine driven alternator(s) to charge both house and chanssis batteries.

Jon,

You can probably see where I'm going with this. If a high amperage path already exists allowing the 50DN to charge the house bank as well as the chassis bank, then a high amperage constant use solenoid is already in place and it would be a simple matter to add a control wire and switch to allow the inverter/chargers to charge the chassis bank. Apparently someone thinks it's okay for the 50DN to charge a disparate collection of batteries; i.e., start lead acid chassis mixed with AGM house.

Jack,

Your air seal probably only takes 10 to 15 psi. I suspect prevost wants 110 psi so that it can perform airbag leveling prior to slide extend/retract???

[jack14r]

Actually I think that the regulator is set at 8 PSI,also Prevost unloads the tag when the front slide is moved and that takes a good deal of air and yes it should be in the normal drive position.I think that there is a vacuum generator to help get the air out of the seal,I might be wrong about the Vacuum generator.I know that there is a lot of compressed air used in moving a front slide,the rear slide does not unload the tag.

[chtree]

Thanks Truk,

I'll pass that on to Joe. I really appreciate the info; they've been looking and were curious about CC service. I knew you guys would know the real deal!

Regards,

Chris

[jack14r]

I checked the owners manual and there is no mention of a vacuum generator but the manual states "Please note that while the slide-out retracts there is a hissing sound.This is normal,as air is being blown in the gear racks on top of the room to clear out leaves,water or other foreign matter"They also state to level the vehicle but my manual only states it for the front slide.

[travelite]

Actually I think that the regulator is set at 8 PSI,also Prevost unloads the tag when the front slide is moved and that takes a good deal of air and yes it should be in the normal drive position.I think that there is a vacuum generator to help get the air out of the seal,I might be wrong about the Vacuum generator.I know that there is a lot of compressed air used in moving a front slide,the rear slide does not unload the tag.

Jack,

Is your chassis built with the pin-less slide technology, as in locking pins?. I believe this technology started in '08. Could be that your chassis is an '07 with the three pins on each slide side. The pin-less stuff had one pin at the center on the bottom.

[jack14r]

Yes mine is the "pin-less"slides with a single pin in each slide in the center underneath.My shell is a 2007 shell that was manufactured 8-2006.I think that the 2007 and newer shells represent the best slide technology that exist today.I am sure that there will be updates in the future but I have not heard of a failure with these slides.

[travelite]

Jack,

Thanks for your patience. I knew that the pinned slide technology suggested dumping/lifting the tag axle, but I didn't know that this protocol was carried thru to the pin-less variety. Thanks for the info.

My apologies for the thread diversion.

[Woody]

FWIW after a full week with both the 24 and 12 switches off the chassis batteries held their full charge (24.1). It appears that TRUC's analysis of the DDEC pulling all down was absolutely correct.

Why is still to be discovered.

[Jon Wehrenberg]

Woody, hate to burst your bubble, but unless your DDEC differs somewhat from ours it will bypass the main disconnect switches to a certain extent. On our vintage coaches and maybe yours CB 19, 20, and 21 are always hot to preserve certain memory in the DDEC. Check those breakers with the main switches off to see if they are hot.

[Woody]

Jon, what we did was read the current draw before and after opening the 12V shutoff. Before 5.2A, after o.o amps. What the "group" theorized was that someone over the last 20 years had tapped into something on the DDEC circuit. I haven't had a chance to search for this drop but will.

[garyde]

Im not sure where your reading the current draw. On my coach the DDEC wires are yellow and they connect directly to the batteries. They do have a small draw.

[truk4u]

Woody was shutting off his 24v cut-off, but not the 12v. The 12v had a draw of about 4 - 5 amps in the on position and when cut-off, went to "0". Now his batteries are holding up and THAT was the purpose of his post.

[michaeldterry]

While we're on the subject of chassis battery charging, I have a related question that will expose my ignorance. Where we store Evangeline, we stay plugged in to 50 amp power all the time when the bus is not in use. Although I try to go out crank her, and let her run up to operating temperature every several days, it can be three weeks or more between actual outings on the road. I've been leaving the engine charge switch at the main electrical panel on all the time while parked at the lot to keep the chassis batteries "topped off". Is this an acceptable practice? If not, what can I do to keep the chassis batteries at peak charge?

[JIM CHALOUPKA]

It all depends on the charging unit.

If it is the type of charger found on my Liberty you will cook your batteries, which means ruin them, in short order if left on continuously.

JIM :)

[michaeldterry]

ACK! Thanks Jim! It looks like I've got some research to do!

[JIM CHALOUPKA]

Michael, you seem to go to your bus often enough, so you might buy a cheap volt meter $3.00 at Harbor Freight and clip it to the battery terminals. Read it when you go to the bus. In this way you will know the charge condition, no guessing. If all is well with your bus the battery will stay up to specs for many months.

:cool:

[michaeldterry]

Thanks again, Jim! That sounds like a practical idea!