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Battery charging

Hey guys, I'm looking for some info on how the battery charging system works on my 92 320
while plugged in at home.  50 amp line to the MH.  I have 3 new 8d batteries all connected
together.  Most info refers to a starting battery and house batts.  Also, how or what does the
boost switch do?
Thanks,
1992 Silver U300 40
DD 6V92 Allison
95K miles

Re: Battery charging

Reply #1 –
The 3 8d's are the house batteries,in case your start batteries fail the boost switch adds the house batteries to the starter,let us know what batteries you have and what charger,will help answer your questions.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Battery charging

Reply #2 –
When plugged in or on the generator ONLY the house batteries will charge. Turn on the boost and all the batteries are combined so even the start batteries will charge. When the engine is running ALL batteries are charging whether the boost is on or not.

With the boost switch on, ALL batteries will discharge as well without hookups or generator on. That's why the boost switch is illuminated. A reminder.
1994 U280, Build 4490
Deming, NM.

Re: Battery charging

Reply #3 –
Quote from: Twig –

With the boost switch on, ALL batteries will discharge as well without hookups or generator on. That's why the boost switch is illuminated. A reminder.

Yes - definitely don't leave boost on unattended.  It's intended to help start the coach if the chassis batteries go low by linking in the house batteries, but things can go south if you forget about it and lose shore power.  Most OEM ones aren't rated for continuous duty, either.
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: Battery charging

Reply #4 –
Quote from: Yurre –
Hey guys, I'm looking for some info...
You should find a 12V wiring diagram B-2126 included with the coach manuals and paperwork.  If not, refer to the diagram linked below.

Note (on the diagram) how the ENG (start) batteries and the COACH batteries are wired.  They are on separate circuits, EXCEPT when the BOOST switch is activated, as explained in the comments above.

The INVERTER/CONVERTER is connected to the COACH batteries.  When plugged into shore power (or generator running) it can charge the ENG batteries only when the BOOST switch is ON.

IN the bottom left corner of the diagram, there is the notation ISOLATOR BOARD with an arrow.  Right where the arrow points you will see the notation "TO ALT".  This is where the engine driven alternator ties into this diagram.  It charges both sets of batteries through the ISOLATOR.

You have been on this Forum since 2018 but are just now wondering how your charging system works?  You must have been very fortunate to not have any questions come up before now.  Most new-to-Foretravel owners are totally mystified by the electrical system right from the very first day of ownership.

https://www.foreforums.com/index.php?action=media;sa=media;in=4746

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Battery charging

Reply #5 –
Quote from: Chuck & Jeannie –
The INVERTER/CONVERTER is connected to the COACH batteries.  When plugged into shore power (or generator running) it can only charge the ENG batteries (unless the BOOST switch is ON).
I believe he means the COACH batteries. The start battery charges only if the engine is running or the boost switch is on.
1994 U280, Build 4490
Deming, NM.

Re: Battery charging

Reply #6 –
Quote from: Twig –
I believe he means the COACH batteries.
Thanx Twig!  My proof reader (ME) failed to catch that error.

I corrected my post.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Battery charging

Reply #7 –
I was somewhat confused by the OP's first post.  Three 8D batteries all connected together?  Is he talking about the COACH batteries?

Looking back through the OP's post history, I see he started a long thread in 2018 (link below) where we all (myself included) tried to figure out how his battery system was configured.  I THINK we finally concluded that he only has three 8D batteries in total, and that they somehow serve as both start and coach batteries.  I don't think we ever saw a photo of the actual battery cable arrangement, so I (for one) was never clear on how his coach is wired.

Batteries etc.

Now he is saying all three batteries are connected together.  How does that work?  Does he even have a isolator, or do both the inverter/converter and the alternator connect directly to the single battery bank?  If that is the case, then the BOOST switch would serve no purpose.  All 3 batteries would be charged from any available charging source.

One of our members, P. Wyatt Sabourin, has run his coach for years with a single combined battery bank.  If he sees this thread perhaps he will review for us how his charging system works.  Batteries

It may be that my comments, and indeed ALL of the comments above, do not actually apply to Yurre's "unique" battery setup.

But we still need to figure out how his charging system is configured...

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Battery charging

Reply #8 –
Think now's the time to wait for Mr. Yurre to answer.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Battery charging

Reply #9 –
Thanks for the replies.  I have been in CE class all day.  What a nightmare.
I'll try to upload a picture of the battery bay.  If there is a separate starting battery, I don't
know where it hides.
Chuck and Jeannie, After I got the MH a friend of mine needed it to live in for a year and half .
So I am just now going through it and getting it ready for a trip to Sheboygan
this fall-maybe.
The owners manual and online info has only confused me more and you guys are so much more helpful.
Y
1992 Silver U300 40
DD 6V92 Allison
95K miles

Re: Battery charging

Reply #10 –
You should have a start battery near the engine.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Battery charging

Reply #11 –
There must be some big differences between a 1992 U300 and a 1993 U300. I have two 8D batteries in parallel on the driver's side just aft of the rear tires. Those are the house (coach) batteries. I have three normal-size batteries, also in parallel, in the engine compartment. Those three start the Detroit.

Re: Battery charging

Reply #12 –
Quote from: Yurre –
Chuck and Jeannie, After I got the MH a friend of mine needed it to live in for a year and half.
So I am just now going through it...
OK, that explains your silence for the past 2 years.  Sounds like you are a good friend of your friend.  ^.^d

A photo of your battery compartment that clearly shows the battery cable routing would be a BIG help.

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Battery charging

Reply #13 –
I (once again) refer all interested parties to the thread from 2018 where we (the Forum members) tried to understand the strange battery setup in this coach.  See Reply #7 up above.

Batteries etc.

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Battery charging

Reply #14 –
Battery bay
1992 Silver U300 40
DD 6V92 Allison
95K miles

Re: Battery charging

Reply #15 –
inverter
1992 Silver U300 40
DD 6V92 Allison
95K miles

Re: Battery charging

Reply #16 –
Quote from: Yurre –
inverter
Might as well start out by using the correct terminology.  The PD9180 is not a inverter - it is a convertor/charger.  See description linked below:

PD9180A - 80 Amp Electronic Power Converter - Progressive Dynamics

If you DO have a inverter on your coach, it is located in another place.  It might possibly look like the Taytronics pictured below (in the storage bay under the entry steps):




1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Battery charging

Reply #17 –
1992 Unihomes and earlier had one battery bay. One of those 8d batteries is the start battery. Someone may have tied them altogether by the looks of the red jumper cable. Do all have equal voltage?
Doug W.
96 36' U270 CSGI #4946
04 Toyota Tacoma 4x4
PNW

Re: Battery charging

Reply #18 –
Quote from: Doug W. –
1992 Unihomes and earlier had one battery bay. One of those 8d batteries is the start battery. Someone may have tied them together by the looks of the red jumper cable.
That is the conclusion we came to back in 2018.  The questions are:
1.  Why?
2.  What other "modifications" were made to the battery and charging systems?

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Battery charging

Reply #19 –
Quote from: Chuck & Jeannie –
That is the conclusion we came to back in 2018.  The questions are:
1.  Why?
2.  What other "modifications" were made to the battery and charging systems?

#1 easy to keep start battery charged when plugged into shore power/ larger battery bank.
Doug W.
96 36' U270 CSGI #4946
04 Toyota Tacoma 4x4
PNW

Re: Battery charging

Reply #20 –
Quote from: Yurre –
Hey guys, I'm looking for some info on how the battery charging system works on my 92 320
while plugged in at home.  50 amp line to the MH.  I have 3 new 8d batteries all connected
together.
So now, having seen your two photos, I can tell you my opinion of how your charging system should work while plugged in at home.

You have three batteries, all connected together.  The PD9180 has two functions.  It is a battery charger, and it is a 12 volt power supply.  It must be plugged into (or hard wired to) a 110V power source to function.

IF your PD9180 is connected to a 110V outlet, and IF it is connected to one of the 3 batteries, and IF the coach is plugged into 50 amp shore power, then all three batteries should receive a charging current.

The PD9180 in base configuration is a "dumb" battery charger.  It may not provide the optimal charge rate for your new batteries.  There is a optional add-on module called a Charge Wizard that will upgrade the PD9180 to a "smart" battery charger.  If you do not already have this module added to your converter/charger, it would be highly recommended.

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Battery charging

Reply #21 –
Quote from: Doug W. –
1992 Unihomes and earlier had one battery bay. One of those 8d batteries is the start battery. Someone may have tied them altogether by the looks of the red jumper cable. Do all have equal voltage?
Yes they do.  And they are new.
1992 Silver U300 40
DD 6V92 Allison
95K miles

Re: Battery charging

Reply #22 –
Quote from: Chuck & Jeannie –
So now, having seen your two photos, I can tell you my opinion of how your charging system should work while plugged in at home.

You have three batteries, all connected together.  The PD9180 has two functions.  It is a battery charger, and it is a 12 volt power supply.  It must be plugged into (or hard wired to) a 110V power source to function.

IF your PD9180 is connected to a 110V outlet, and IF it is connected to one of the 3 batteries, and IF the coach is plugged into 50 amp shore power, then all three batteries should receive a charging current.

The PD9180 in base configuration is a "dumb" battery charger.  It may not provide the optimal charge rate for your new batteries.  There is a optional add-on module called a Charge Wizard that will upgrade the PD9180 to a "smart" battery charger.  If you do not already have this module added to your converter/charger, it would be highly recommended.


Cool, where would I get this upgrade module?
1992 Silver U300 40
DD 6V92 Allison
95K miles

Re: Battery charging

Reply #23 –
Quote from: Yurre –
Cool, where would I get this upgrade module?
Shop around online for the best price.

Charge Wizard PD9105 RV Battery Chargers

Amazon.com: Progressive Dynamics PD9105V TCMS Charge Wizard: Automotive

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Battery charging

Reply #24 –
Quote from: Chuck & Jeannie –
Might as well start out by using the correct terminology.  The PD9180 is not a inverter - it is a convertor/charger.  See description linked below:

PD9180A - 80 Amp Electronic Power Converter - Progressive Dynamics

If you DO have a inverter on your coach, it is located in another place.  It might possibly look like the Taytronics pictured below (in the storage bay under the entry steps):





yes I have the inverter in the bay with the compressor
1992 Silver U300 40
DD 6V92 Allison
95K miles