Chassis Battery Charging

[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.