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Old 04-14-2013, 04:25 PM   #21
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Originally Posted by VinceU View Post
Just wondering, can those output leads be doubled to allow for the high current? IE: if the AWG is small but doubled to carry all the ampacity the batteries can deliver vs single heavy cables each polarity?
Vince,
I am not sure what you are driving at. His issue is not with the current out of the stack, but the unbalanced resistance of the batteries.
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Old 04-14-2013, 05:26 PM   #22
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The electrical resistance between the Positive and Negative end points is not "negligible" when you are charging or discharging the batteries when you consider that one battery (set in your case) will work harder than the other at all times. That will lead to early failure of one battery set (could be why you are having problems).

This is how 2 12 volt batteries should be connected to balance the current into and out of a bank.

After reading your PDF file I could only say to myself "Well, I'll be damned".

I never would have thought that it could make that much difference. Maybe that IS my problem, although I'm not sure what I could do to get them more balanced. I'll think about it.

Thanks for sharing.

Boowho??
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Old 04-14-2013, 06:08 PM   #23
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That's why I started "just wondering"
That said seems the coach is three years old already and Boohoo is a full timer. If the batteries have been "on charge" most of that time, regardless of the wiring its not unusual for a battery to sulfate and eventually short out.
Still don't know where the four leads go, if all to the same power control center for solenoid control as most coach designs do, it would seem to me the wiring is goofy but perhaps two each pole was necessary to carry the current. Gotta believe the coach batteries are switched from the chassis batteries via the Intellic or SDC control panels.
Most of all the system survived for 3 years, they must have done something right?
Must admit that is some strange wiring, anybody with a Berkshire see the same?
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Old 04-14-2013, 06:42 PM   #24
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That's why I started "just wondering"
That said seems the coach is three years old already and Boohoo is a full timer. If the batteries have been "on charge" most of that time, regardless of the wiring its not unusual for a battery to sulfate and eventually short out.
Still don't know where the four leads go, if all to the same power control center for solenoid control as most coach designs do, it would seem to me the wiring is goofy but perhaps two each pole was necessary to carry the current. Gotta believe the coach batteries are switched from the chassis batteries via the Intellic or SDC control panels.
Most of all the system survived for 3 years, they must have done something right?
Must admit that is some strange wiring, anybody with a Berkshire see the same?
I bought the coach last November. It was "used" (titled) but never taken out. Original owner bought it August of 2011.

He did charge the batteries off the generator periodically; I don't know how often. Knowing him, it was probably at least twice a month. With only 3072 miles on the chassis but 49 hours on the genset, I'd say fairly often.

Manufactured date late 2010 or early 2011. Chassis came off FL line in Oct 2010.

In reading Herk's PDF file (I'm still stunned to learn what was in there), maybe I should just move the two pos inputs to the coach to one end of the stack (same pos post) and then move the two neg inputs to the same post on the other end of the stack (same neg post).

That way I'd be about as balanced as I can get. Still I'd be a little worried about by FR did it that way (as shown in my original pic) in the first place.

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Old 04-14-2013, 06:54 PM   #25
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I bought the coach last November. It was "used" (titled) but never taken out. Original owner bought it August of 2011.

He did charge the batteries off the generator periodically; I don't know how often. Knowing him, it was probably at least twice a month. With only 3072 miles on the chassis but 49 hours on the genset, I'd say fairly often.

Manufactured date late 2010 or early 2011. Chassis came off FL line in Oct 2010.

In reading Herk's PDF file (I'm still stunned to learn what was in there), maybe I should just move the two pos inputs to the coach to one end of the stack (same pos post) and then move the two neg inputs to the same post on the other end of the stack (same neg post).

That way I'd be about as balanced as I can get. Still I'd be a little worried about by FR did it that way (as shown in my original pic) in the first place.

Boowho??
Do motor homes come stock with 4 six volt house batteries?
Maybe the original owner had them installed by a local shop.
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Old 04-14-2013, 07:09 PM   #26
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Do motor homes come stock with 4 six volt house batteries?
Maybe the original owner had them installed by a local shop.
I don't they were installed after delivery. The tray EXACTLY fits four batteries, and I believe that bigger coaches like this (DP) probably have 4x6 as standard equipment.

Plus if he had them installed later, the paperwork would have been in the stuff he gave me. He was extremely fastidious about such things; to the point of being a nit picker

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Old 04-14-2013, 07:23 PM   #27
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Do motor homes come stock with 4 six volt house batteries?
Maybe the original owner had them installed by a local shop.
I've seen it advertised in DP chassis, someone else in the forum with a 10 or 11 Berk commented on changing them. From memory they are on a slideout tray, nice setup. Anyway Boohoo has confirmed they are at least 3 years old, and we all know 30 minute charges a few times may not enough. Maybe change the cables and see what happens, that one battery is probably gone, I've had it happen over the years but only had to change one at a time.
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Old 04-14-2013, 08:02 PM   #28
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I've seen it advertised in DP chassis, someone else in the forum with a 10 or 11 Berk commented on changing them. From memory they are on a slideout tray, nice setup. Anyway Boohoo has confirmed they are at least 3 years old, and we all know 30 minute charges a few times may not enough. Maybe change the cables and see what happens, that one battery is probably gone, I've had it happen over the years but only had to change one at a time.
Well, if I only have to buy ONE that will be good news. I thought I read once before that the entire array (all bats) needed to swapped out at the same time.

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Old 04-14-2013, 08:10 PM   #29
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Well, if I only have to buy ONE that will be good news. I thought I read once before that the entire array (all bats) needed to swapped out at the same time.

Boowho??
That is my understanding as well.
As I understand it having a new battery and a older battery in the same cell will lead to a reduction in combined capacity due to a variance in the number of cycles between them. The stronger battery will self discharge into the older battery.

Here is an article that shows the reduction in capacity due to charge/discharge cycles.
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Old 04-14-2013, 08:17 PM   #30
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Well, if I only have to buy ONE that will be good news. I thought I read once before that the entire array (all bats) needed to swapped out at the same time.

Boowho??
Sorry, what I meant was heretofore that's all I had, one Group 24 battery for coach, one chassis start battery. By the way, the start batteries always far outlast the coach batteries. That's in both Class A and C motorhomes. This present one has two large coach batteries size 27 I think and one standard Ford chassis start battery.
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Old 04-14-2013, 08:33 PM   #31
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Boo's diagram is factory stock

I have a 2008 Berkshire. The diagram Boo first posted is how the Berkshire comes from the factory. You probably just have a battery gone bad. I have lost two. One last year and one this year. Same thing, one cell boils off. They are cheep batteries from the factory.
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Old 04-14-2013, 08:38 PM   #32
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I just checked and the inverter is on one of the cable pairs, the rest of the coach is on the other the other cable pair.

I could remove two longer jumpers and have two separate 12V systems, I guess. But then the inverter bats couldn't "help" the house bats when needed, nor the other way around.

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Old 04-14-2013, 08:48 PM   #33
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I just checked and the inverter is on one of the cable pairs, the rest of the coach is on the other the other cable pair.

I could remove two longer jumpers and have two separate 12V systems, I guess. But then the inverter bats couldn't "help" the house bats when needed, nor the other way around.

Boowho??
That is correct.
Also, since the second set are "Load only" it is not a big deal and should not impact the charge/discharge issue (I think - depends on whether they are cross battery connected).

The X wires go to the inverter.
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Old 04-14-2013, 09:07 PM   #34
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I had the same problem with my 6 volt batteries on my golf cart recently, hooked up my charger and could hear something boiling. Disconnected and checked all my connections and water in each cell. Checked output of my charger also. Everything was perfect. Hooked charger back up and did the same thing. Removed that battery, which was fun.... and had it load tested. Battery tested bad. Replaced battery, just keeping my fingers crossed that I can a little more life out of the other batteries.
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Old 04-14-2013, 09:54 PM   #35
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I just checked and the inverter is on one of the cable pairs, the rest of the coach is on the other the other cable pair.

I could remove two longer jumpers and have two separate 12V systems, I guess. But then the inverter bats couldn't "help" the house bats when needed, nor the other way around.

Boowho??
Would you install a small charger for the inverter batteries?
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Old 04-14-2013, 10:29 PM   #36
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Would you install a small charger for the inverter batteries?
I do not recommend separating them. Either replace just the bad one or (recommended) all four.
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Old 04-15-2013, 10:42 AM   #37
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I have a 2008 Berkshire. The diagram Boo first posted is how the Berkshire comes from the factory. You probably just have a battery gone bad. I have lost two. One last year and one this year. Same thing, one cell boils off. They are cheep batteries from the factory.
Silver, nest time you're back there, could you verify that your coach is wired the same as this drawing with regard to the feed wires going to the inverter and the coach circuit??

I'm wanting to make sure I put the green wires back in the same place. I'm good to go with the blue wires.

Boowho??
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Old 04-21-2013, 10:28 PM   #38
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i'm picking my new 390bh up tomorrow. i'll take a pic of the battery bay and trace those down for you if Silver doesn't get a chance to before then...

i'm not an electrical engineer but to me, it seems either lead pair is not pulling a balanced load based on your diagram. each lead pair is pulling from half the bank first instead of from across the entire bank of batteries. based on what i have learned, to get a balanced pull you would want to have the positive and negative leads connected at the furthest ends of the bank from each other. so in your diagram, go diagonal corners for your connect points to get the draw balanced acrossed all 4 batteries instead of just two...

i'm sure an electrical engineer can clear this up better than me...

the diagrams posted before in this thread do show a balanced draw across the entire bank..
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Old 04-21-2013, 10:32 PM   #39
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To balance the bank, the lower two connections should be swapped.

The inverter positive should go on the other batteries positive and the "Camper's" positive should go where the inverter's is now.
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Old 04-22-2013, 10:39 AM   #40
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Boowho

I have been away thus the reason for no response. Yes as I stated in my first post your drawing is correct. I like it so much I have taken a copy for my files. Saves me the trouble of sketching one. As for the loading and balance issue I see discused. The battery cables on my coach are all 1 AWG wire. With wire that thick it will make little difference which post the wire is attached as for loading. It should be transparent for all intents and purposes.

When I had a lot of acid I had a bad battery. I replaced the battery and most of the outgassing and acid formation has gone away. I still have some. I believe that the battery compartment could be better vented but it is not. What I plan to try next is to remove the battery tray and rails and spray the bottom of the compartment, rails, and battery with truck bed liner. Perhaps that will seal up the metal and prevent the acid from forming. Have to treat with baking soda first to netrulize any acid.

Hopes the info helps
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