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Author Topic: Chassis battery charging modifications  (Read 758 times)

Henry J Fate

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Chassis battery charging modifications
« on: July 13, 2018, 07:46:40 AM »
Hello Friends

My 2001 Brave does not charge the chassis battery when on shore power. This week I used a jumper cable to charge the chassis battery using the house charging circuit. My chassis battery is a deep cycle battery as is the house batteries. I browsed around looking for permanent fixes but did not find  enough info to make a final decision.

I would prefer to have the chassis battery charge from  the stock converter/charger during shore power connection.

I have a few questions.

What is the reason for not offering this feature from the factory?

Has anyone designed a modification to safely accomplish this?

Thanks in advance

Henry-

Optimistic Paranoid

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Re: Chassis battery charging modifications
« Reply #1 on: July 13, 2018, 08:45:33 AM »
It can depend on what the RV uses as an isolator between the house and chassis batteries.  If it's a solenoid, it would be easy to come up with a little jumper clip that would leave the batteries paralleled so the convertor current would flow to the chassis battery too.  With a diode type isolator, I'm not sure if that could be done or not.
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Gary RV_Wizard

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Re: Chassis battery charging modifications
« Reply #2 on: July 13, 2018, 09:00:03 AM »
You want a device called a Trik-L-Start. It's a well known and reliable solution for chassis battery charging in the many Winnebago coaches that lack that feature.

http://www.lslproducts.net/TLSPage.html

If you want a bit more elegant solution, you could choose a Magnum Smart Combiner or the Xantrex Echo Charge, but the Trik-L-Start does the job handily.
For a long time Winnebago (and a few other RV makers) believed that  their owners did not camp for extended periods (more than a few days at a time) and did not plug their rigs in at home. Therefore charging from shore power was an unjustifiable extra cost in their product. [Fleetwood came to the opposite conclusion, but that's what makes horse-racing!].  After numerous complaints about dead chassis batteries, Winnebago eventually added the feature to its diesel pushers and after a further delay, to many of the gas-chassis models as well.
« Last Edit: July 13, 2018, 09:06:11 AM by Gary RV_Wizard »
Gary
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John From Detroit

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Re: Chassis battery charging modifications
« Reply #3 on: July 13, 2018, 11:06:26 AM »
Q1:What is the reason for not offering this feature from the factory?
A1:$$$$$$$$$$$  Cost a couple of bucks

Q2:Has anyone designed a modification to safely accomplish this?
A2: YES  Trick-L-Start is one such product (google it) And Echo Charge is another Two different companies nearly identical products.

Both install very simply.. Locate your ISOLATOR solenoid. this will have likely two small wires and two BIB ones. Ignore the small ones.
The big ones one is HOUSE and one is Chassis.

ENgine off, not plugged in the HOUSE one should read 13.6 and the other 12.6 or there about.
The device has 3 leads.
One is ground, Find a good ground spot and attach
one is Chassis or Main, Hook that to the BIG terminal that reads 12.x
The remainder is HOUSE it gotes to the 13.X terminal
Mount the case and. Job done.

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Henry J Fate

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Re: Chassis battery charging modifications
« Reply #4 on: July 13, 2018, 02:07:29 PM »
A couple of weeks ago I found the trik L start. It apoears to be an easy way of solving the problem. Thanks to Gary and John. Before I commit to adding an additional charging component, I would like to be sure that there Isn't an easy modification to the existing charging system.

Pretty sure my system works as follows...

1.The engine charges both the chassis and the house batteries.
2. Shore power only charges the house batteries.
3. The generator only charges the house batteries
4. I have a momentary aux start switch which combines the chassis batteries and the house batteries while it is manually held in the on position. This is to be used to draw current from house batteries for starting the engine if needed or possibly even used to start the generator if the house batteries got to low.
5. If I am running the generator or plugged into shore power and activate the momentary aux start switch, my volt meter is signaling a charge to the chassis battery.

These conditions lead me to suspect that the momentary switch is used to prevent drawing off the chassis battery if it was able to be left in the on position with no shore or generator power.  There could also be some concern of competing charging circuits with the engine alternator and the charger/converter with the engine running and the genorator running or plugged into shore power.

I wonder if I could change the momentary switch to a normal on/off rocker switch and be able to combine the batteries if needed. I do remember some of the older systems working similar. The only draw back to that is that if you leave the switch on without the generator running or plugged in, you could reduce all your batteries to a point  where you couldn't start the engine or generator. That would be fine with me if it is safe to change the switch.

Any help with that would be greatly appreciated.

Thanks again for all the help.

Fyi.... My generator has been working just wonderful.

Henry



Alfa38User

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Re: Chassis battery charging modifications
« Reply #5 on: July 13, 2018, 03:02:51 PM »
Could you??? yes but...

The Trk-L-Start has electronics in it that prevents stealing the current from the house battery charge if the house batteries are too low to start with. It only functions when the converter is charging the house batteries and after they are at a certain state of charge.

With the mod you are suggesting, YOU become the controller and hopefully you don't forget that switch and leave it in the wrong position. You would be be making one BIG battery serving both the house and chassis battery by the simple mod you are suggesting when left in the "ON" position. You did recognize that in saying "The only draw back to that is that if you leave the switch on without the generator running or plugged in, you could reduce all your batteries to a point  where you couldn't start the engine or generator."
« Last Edit: July 13, 2018, 03:08:52 PM by Alfa38User »
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Optimistic Paranoid

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Re: Chassis battery charging modifications
« Reply #6 on: July 13, 2018, 03:08:00 PM »
Sounds to me like you've got a solenoid isolator.  The momentary switch provides power to the solenoid, activating it so the batteries are combined.  So yeah, if you replaced it with a "normal" switch you would defeat the isolator and the house and chassis batteries would be combined.
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PJ Stough

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Re: Chassis battery charging modifications
« Reply #7 on: July 13, 2018, 03:39:25 PM »
Q1:What is the reason for not offering this feature from the factory?
A1:$$$$$$$$$$$  Cost a couple of bucks...


I imagine one reason would be at least on older Winnebagos that were plugged into shore power for more that a few days at a time, the onboard converter/charger would over charge and eventually ruin the engine battery.
PJ Stough   Iowa
2005 Winnebago Voyage 38J

Henry J Fate

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Re: Chassis battery charging modifications
« Reply #8 on: July 13, 2018, 09:31:39 PM »
There are many things to consider. It does appear that the quick fix would be to change the momentary switch to a standard one. My opinion is that the switch does activate a relay solenoid that introduces the house batteries to the starting battery. Is this method used for charging the chassis and house batteries when the coach engine is running?  If not, could there be two different charging circuits from the engine? One for the starting battery and one for the deep cycle house batteries? Deep cycle batteries like to be charged a little different than a starting battery. Charging methods will influence the life expectancy of the batteries and the quality of their life.

I bring this up because by changing the momentary switch to a standard switch, it becomes  possible to combine the charging sequence by leaving the switch on while the engine is running. The other issue is that my starting battery is a deep cycle battery. I didn't plan to do this but it just happened to be the best choice at the time. I think possibly the charging sequence for the starting battery could be improper for the deep cycle. Or maybe Winnebago did not get too detailed in their charging design and have one charging circuit off the engine for all the batteries.

The Trik L Start system may offer some other advantages like friendly charging of the different types of batteries at different charge states. Much to think about. Changing the switch seems to easy.

Enjoy the weekend

Henry

Gary RV_Wizard

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Re: Chassis battery charging modifications
« Reply #9 on: July 14, 2018, 11:42:47 AM »
Quote
Is this method used for charging the chassis and house batteries when the coach engine is running?
Yes.  +12v from the engine alternator is used to close the solenoid (relay) and cross-connect the two systems.  You could do the same from the house side, either permanently or via a manual switch (instead of the momentary), but the risk is that you will some day discharge the chassis battery and get stranded.  Folks always say they would never do that, but the whole reason that RV builders install isolation systems is that history has shown they are necessary to avoid frequent problems.  RV builders are notorious penny-pinchers, yet they feel this extra expense is needed.  In fact, RVIA manufacturing standards require it.
Gary
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Henry J Fate

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Re: Chassis battery charging modifications
« Reply #10 on: July 15, 2018, 09:13:17 AM »
That's good info Gary. I should be able to confirm this by locating the solenoid and verifying it is energized with the engine running. Do you have any idea how the engine charging circuit protects itself from competing charging currents? Ex: running the generator and running the coach engine at the same time. It would seem that there would need to be some sort of priority in this example. I suspect diodes could be used but that alone wouldn't necessarily guarantee a proper charging sequence but would isolate competing charge voltages.

My other concern that has given me reason to sort this out is this....

It seems fairly easy to have the combining solenoid energized when plugged in or if the generator is running. This, coupled with the momentary switch, seems to make far more sense. Couple of ways to do this. Simply connect the solenoid to the converter/charger so that whenever the coach is receiving 110v and powering up the converter/charger, the solenoid combines the batteries. The other way would be to install an additional solenoid which responds to 110 volts which in return would combine the batteries.

The above methods seem all to easy. Especially the first one which leads me to wonder if there are factors other than functionality that come into play.

Thanks for everyone's help.

Henry


Gary RV_Wizard

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Re: Chassis battery charging modifications
« Reply #11 on: July 15, 2018, 09:33:56 AM »
No protection between the two systems, largely because no practical problem has been demonstrated.  These DC systems intersect at the batteries, and the batteries react to which ever is applying the higher voltage.  The engine alternator is essentially an unregulated charger and over a long enough time would possibly overcharge the house batteries, but few people travel enough hours every day for this to be a concern.  The house charging system is effectively idle while the alternator is operating, simply because the alternator typically is pushing a high enough voltage that the batteries look to be fully charged (from the perspective of the house charger).
Gary
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Henry J Fate

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Re: Chassis battery charging modifications
« Reply #12 on: July 15, 2018, 09:56:30 AM »
Very interesting Gary. Without testing to confirm this, I believe it to be true. Do you think that using the existing solenoid, to respond to a powered up converter/charger,  would be an adequate fix? Installing a new 110 volt relay would probably be a little more complicated.

My other question would be.....

Has anyone any knowledge of this modification  being successfully executed? Just seems that someone somewhere must have looked into this or completed it.

Thanks

Henry

Charlie 5320

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Re: Chassis battery charging modifications
« Reply #13 on: July 15, 2018, 03:31:05 PM »
Very interesting Gary. Without testing to confirm this, I believe it to be true. Do you think that using the existing solenoid, to respond to a powered up converter/charger,  would be an adequate fix? Installing a new 110 volt relay would probably be a little more complicated.

My other question would be.....

Has anyone any knowledge of this modification  being successfully executed? Just seems that someone somewhere must have looked into this or completed it.

Thanks

Henry
Many years ago Winnebago used a 3 way switch to accomplish this. One way was momentary, middle off, other way on. The problem was if you left it in the on position when the coach was stored, many times you would end up with both sets of batteries DEAD. Being the BCC you have don't do this, is to install a battery tender on the chassis battery. Battery tenders can be bought pretty cheap and it will maintain the battery to the correct voltage without over charging it.
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Gary RV_Wizard

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Re: Chassis battery charging modifications
« Reply #14 on: July 15, 2018, 04:02:04 PM »
I don't know of anyone who has done that modification, but many coaches have a Battery Control Center (BCC) that does exactly that.  The solenoid in question is part of the BCC system.

A concern is that the solenoid has to be capable of continuous duty, i.e. days and days with the solenoid engaged.  Obviously the one in your rig can do several hours while driving, but I don't know about days on end.
Gary
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Henry J Fate

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Re: Chassis battery charging modifications
« Reply #15 on: July 15, 2018, 06:41:02 PM »
Thanks for the info Charlie. About 25 years ago I had a coachman classic which had a 2 position switch either on or off. I dint recall any problems back then but I am using this current coach a little different. What bothers me is that I currently have 2 charging sources for the batteries. Adding a third just doesn't sit well in my thinking but in the end, may be the best choice. I do believe that the existing charge circuits are adequate but need better management.

You bring up a good point Gary. I would think they probably didn't swing to far from what would be a continuous solenoid but it is something I would need to check to be sure. I should have some time this week to look the modification.

Thanks for all the help.

Henry

Henry J Fate

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Re: Chassis battery charging modifications
« Reply #16 on: July 16, 2018, 10:22:28 AM »
As I fell asleep last night, I had some thoughts and another option. Install a new 12 volt solenoid in the battery box that responds to a powered converter /charger. This would be fairly simple because all the batteries  are there and there are secondary battery terminals that will accommodate the additional cabling. I would only possibly need to run power from the converter to the battery box. I would leave the current momentary switch as is and not include a switch for the new solenoid. Let it automatically charge when plugged in.

Still thinking about this. My other thought is that I neef a good BBC. That might be too much to ask.

Henry

Gary RV_Wizard

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Re: Chassis battery charging modifications
« Reply #17 on: July 16, 2018, 10:47:23 AM »
Devices like the Trik-L-Start aren't a third charging source.  It's merely a parallel isolator solenoid that operates under the control of a circuit board designed to manage house + chassis battery charging safely and effectively.  Seems to me you are doing a lot of studying to avoid using a proven and inexpensive solution. For $30 you get everything you need to do the job and the operation is fully automatic after the simple installation.

http://www.bestconverter.com/TRIK-L-START_c_210.html
Gary
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Henry J Fate

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Re: Chassis battery charging modifications
« Reply #18 on: July 16, 2018, 01:41:43 PM »
Yes Gary you are correct. The Trik L Start device is not a source of charge voltage but rather a switch for an existing charge supply. I had to think back and read some. My converter / charger is the Magnetek 7445 45amp. It's a beast compared to the output management of the Trik L Start claiming to use up to 45 amps of charging if needed. Some good and bad with that but since I am using relatively cheap deep cycle batteries, I am not too concerned about the large charging rates as far as life expectancy of the batteries. The Magnetek does have a reduced voltage following a period of time at the initial voltage. Better than nothing I guess and probably not the best choice of charging profiles. The 5 amps max from the Trik L Start may be just fine most if not all of the time. I have seen them for about $35 on the internet.

Henry

Gary RV_Wizard

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Re: Chassis battery charging modifications
« Reply #19 on: July 17, 2018, 11:00:22 AM »
https://www.rvupgradestore.com/Ultra-Trik-L-Start-p/tls-oem.htm

5A is plenty - you are only maintaining the chassis battery, not re-charging a dead one. And the 5A peak won't harm it even if 24/7, which is the advantage of having separate charge management instead of the house charging trying to treat the house + chassis as a single battery bank.   
Gary
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Henry J Fate

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Re: Chassis battery charging modifications
« Reply #20 on: July 18, 2018, 07:53:55 PM »
Thanks alot Gary. Can't beat that for $30. I think this is the best resolution and will extend the life of the chassis battery and increase the quality of life. My chassis battery is left over from the initial purchase of the coach. The coach came with a starting battery for the chassis and one deep cycle house battery. The chassis battery was bad at purchase (not surprising)  and finally checked out shortly after purchase. I wasn't sure of the condition of the one house battery so I changed its duty to the chassis and bought two new deep cycle house batteries. So far its been great. The chassis battery is a little low on cca but I doubt I will be in any cold  weather and if I do and the battery needs some help,  I can use the handy dandy winne momentary engineering wonder. :-). They had it right all along. They just forgot to install the Trik L Start.

Thanks again to all.

Henry