Parallax Power Converter 7455BT Question

[Jserna]

I have a 2008 Winnebago Adventurer with a Parallax 7455BT converter. My question is: Should the house batteries be charged by the alternator while the vehicle is running?

I have checked and the charging system seems to be working properly when the coach is hooked to house power. The system also charges correctly when the Onan generator is running.

I do not see that the system is charging when there is no 120v power source. I believe the house battery charging system should be working if the motor is running.

Am I correct or not?

If the system should charge with the alternator, any ideas as to why mine is not charging properly.

Thank you

[edgray]

Originally Posted by Jserna

I have a 2008 Winnebago Adventurer with a Parallax 7455BT converter. My question is: Should the house batteries be charged by the alternator while the vehicle is running?

I have checked and the charging system seems to be working properly when the coach is hooked to house power. The system also charges correctly when the Onan generator is running.

I do not see that the system is charging when there is no 120v power source. I believe the house battery charging system should be working if the motor is running.

Am I correct or not?

If the system should charge with the alternator, any ideas as to why mine is not charging properly.

Thank you

The engine alternator does not normally charge the house batteries, because it is not set up as a power input to the converter. The converter only gets power input from the genset or another 120V source like a CG pedestal.

I believe the two battery banks are kept separate by design. Some coaches are equipped with a device commonly called a "BIRD" which allows current to flow in both directions under specific & limited circumstances, however I don't believe WBGO provides such a feature. They do recommend the use of a Trik-L-Start, which MAY provide some power to the house batteries from the chassis battery, but the TLS is primary sold as a means of keep the chassis batty topped off when the coach batteries are fully charged and getting power from the converter.

[twinboat]

Almost ALL MHs charge the house batteries from the alternator.

Somewhere is a solenoid that closes when voltage is sensed from the engine driven alternator. Most have a slight delay so the engine battery is topped off first.

You need to look for a battery control center and look for a solenoid. It will have 2 large cables, one from each battery bank going to it.

A simple test will be to have the engine running and put a test probe from a volt meter on the big posts on each side of the solenoid, while having the other probe to a clean price of steel or a negative battery post.

You should read the same voltage (13.5) on both sides of the solenoid.

If they are not the same, touch the probe to one of the small terminals. 1 should show 12 + volts.

If the small post has volts and the big ones are not the same voltage, the solenoid is bad.

They fail often. If you decide to replace it be sure to get a continous duty solenoid.

This system is common in most MHs and has nothing to do with the 120 volt charging system, pluged in or powered by generator.

[twinboat]

Originally Posted by edgray

The engine alternator does not normally charge the house batteries, because it is not set up as a power input to the converter. The converter only gets power input from the genset or another 120V source like a CG pedestal.

I believe the two battery banks are kept separate by design. Some coaches are equipped with a device commonly called a "BIRD" which allows current to flow in both directions under specific & limited circumstances, however I don't believe WBGO provides such a feature. They do recommend the use of a Trik-L-Start, which MAY provide some power to the house batteries from the chassis battery, but the TLS is primary sold as a means of keep the chassis batty topped off when the coach batteries are fully charged and getting power from the converter.

If your MHs is not charging the house bank while the engine is running, something is wrong.

I have yet to hear of a MH that does not offer this feature.

The trik-l-start is a owner add on to charge the start battery from the house system. If you have a BIRD system it is not needed.

BIRD = Bi-directional Isolation Relay with Delay.

[tderonne]

This gets asked what seems like every week. The solenoid Winnebago used is not up to the task. Search here for Winnebago solenoid or Trombetta, you'll find everything you need to know.

Here's sample thread

And another

[grtharris]

Jserna, The drawing below is of your chassis electrical box. The solenoid in the red circle is the one that connects the chassis batteries to the coach batteries when the engine is running or when you press the Battery Boost switch.
As noted above this relay is somewhat of a weak point in the battery charging system.

[Jserna]

Thank you everyone that responded. I have found that the solenoid indeed need to be replaced. There seemed to be plenty of information on the correct replacement unit. I have chosen the Napa ECH ST80. It is a 4 post solenoid with silver contacts. A seperate ground wire will need to added, but other threads agree that this seems to be a very good option. Research does show that the house batteries should be charged by the vehicle alternator. Thanks again.

[ladagobago]

Originally Posted by Jserna

Thank you everyone that responded. I have found that the solenoid indeed need to be replaced. There seemed to be plenty of information on the correct replacement unit. I have chosen the Napa ECH ST80. It is a 4 post solenoid with silver contacts. A seperate ground wire will need to added, but other threads agree that this seems to be a very good option. Research does show that the house batteries should be charged by the vehicle alternator. Thanks again.

Since you appear to be new to this MH thing and forum let me advise that you remove the negative cable from both the chassis and house batteries before removing any wires from the solenoid. no fires please

[Jserna]

Originally Posted by grtharris

Jserna, The drawing below is of your chassis electrical box. The solenoid in the red circle is the one that connects the chassis batteries to the coach batteries when the engine is running or when you press the Battery Boost switch.
As noted above this relay is somewhat of a weak point in the battery charging system.

Hello Grant,
This is JSerna again. I purchase the ST80 solenoid a month or so ago, but have not had a change to install it yet. I know that I need to add a ground wire to the 4th terminal but I am not sure which of the small terminals is the correct one to use for the ground. Do you have that answer?

[ChasA]

JSerna, you should put the ground wire on the small terminal that is marked - (minus).

[twinboat]

Originally Posted by ChasA

JSerna, you should put the ground wire on the small terminal that is marked - (minus).

Maybe a picture of the small terminal with - (minus) will help.

I don't recall seeing it on any of them.

[grtharris]

Jserna, if there is not a letter G or a - (minus) near one of the small terminals it does not make any difference which one to ground wire goes on.

[Jserna]

Thank for the responses. There are no markings on small terminals to note a ground or (-).