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.