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EricR

New Member
Thanks.

I didn't add it because its not connected :).
:)
I believe mine already showed that.
Yes, now that I look at it again I can see it does!
Means the same thing, no?
I will amend my statement to include the break peddle also needs to be de-pressed.
Which makes it less of an issue.

What condition?
Having the house battery feed current to the brake controller's output.
Having your house system integrated with a system without fuses is a concern to me.
My big concern is, if anything went wrong and the break-away system failed your insurance might look for an out.
OK, now I'm 95% sold on a separate breakaway setup.
 

EricR

New Member
Hopefully the blue(brake) wire is fused at the vehicle side.
If the 2 batteries(which may be at significantly different voltages) are connected in parallel, you will likely have fire hazard levels of current flowing through that wire.
Ironically the voltage drop of the long thin wire might mitigate things a bit.
OK, I'm 100% sold on a separate breakaway setup! 😄

Now it seems like very inexpensive insurance.

Thanks for all of your knowledge and help!
 

EricR

New Member
Though I am still curious about the validity/practicality of the idea @12VoltInstalls raised of using a diode to prevent backflow (for lack of a better term) from the house battery to the tow vehicle.

@shadowsteve was also commenting/asking about the use of a diode. I'm not sure his question(s) were answered.

Regards,

-Erci
 

EricR

New Member
Wow, Amazon had a break-away kit with case, battery and wiring for under $15! I'll need to reuse my existing switch and dig up some self-tapping mounting screws.
 

12VoltInstalls

Solar Addict
curious about the validity/practicality of the idea @12VoltInstalls raised of using a diode to prevent backflow (for lack of a better term) from the house battery to the tow vehicle.
I guess that’s a circuit that would do that.

The point was to protect the breakaway battery- although I suppose it is still vulnerable to discharge, the chemistry or voltages were of concern.
Two diodes I guess would solve that…
 

shadowsteve

Solar Enthusiast
If the manufacturers ship a trailer with the breakaway system tied to the installed battery system why are you changing this situation when installing a replacement battery system? The battery technology should have no bearing on how the system is wired for this function.

This is the engineering drawing for the DC interconnect on my '14 Jayco fifth wheel. The switch is tied to the battery through the main 50A auto-reset breaker that's in the battery compartment. With the prior AGM install I connected into the point on the left of the 50A brkr and will do functionally the same with the LFP system. In this way I've not altered what Jayco designed. I don't have the drawings that show the incoming 7pin connection but would expect it's just tied to the breakaway switch at the pinbox and on to the brakes.
 

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12VoltInstalls

Solar Addict
The battery technology should have no bearing on how the system is wired for this function.
Solar into lfp feeding into a ken-and-barbie sla could have bad consequences.

There’s no harm in improving things.
An independent brake battery isolated from ‘house’ assures good brake function even after sucking the house batteries down with breakfast or whatever.
For the money? Why not?
Manufactured Item Dependency Syndrome prevents innovation and in this case, imho, a more robust layer of safety. YMMV; plan your sensibilities accordingly.
 

shadowsteve

Solar Enthusiast
Solar into lfp feeding into a ken-and-barbie sla could have bad consequences.

There’s no harm in improving things.
An independent brake battery isolated from ‘house’ assures good brake function even after sucking the house batteries down with breakfast or whatever.
For the money? Why not?
Manufactured Item Dependency Syndrome prevents innovation and in this case, imho, a more robust layer of safety. YMMV; plan your sensibilities accordingly.

Not sure what you mean by "Solar into lfp feeding into a ken-and-barbie sla could have bad consequences". If a trailer is running LFP then there is no SLA/FLA unless you've added a brake battery system which means another battery to maintain. This compromises the safety of the system rather than enhances it IMO. I'll stick to powering the brakes off my properly maintained and monitored house batteries.

It'll only be required to function properly once in it's life but that's a fairly important "once" :)
 

smoothJoey

SmooJo
If the manufacturers ship a trailer with the breakaway system tied to the installed battery system why are you changing this situation when installing a replacement battery system? The battery technology should have no bearing on how the system is wired for this function.

This is the engineering drawing for the DC interconnect on my '14 Jayco fifth wheel. The switch is tied to the battery through the main 50A auto-reset breaker that's in the battery compartment. With the prior AGM install I connected into the point on the left of the 50A brkr and will do functionally the same with the LFP system. In this way I've not altered what Jayco designed. I don't have the drawings that show the incoming 7pin connection but would expect it's just tied to the breakaway switch at the pinbox and on to the brakes.
I must be seeing things wrong.
I think I am seeing the power converter is connected to both sides of the disconnect switch.
So the circuit includes a disconnect switch which doesn't disconnect.
What the foop is this soup?
 

shadowsteve

Solar Enthusiast
I must be seeing things wrong.
I think I am seeing the power converter is connected to both sides of the disconnect switch.
So the circuit includes a disconnect switch which doesn't disconnect.
What the foop is this soup?
The connection to the left side of the switch is from the charger portion of the unit. The right side is the 12v feed to the trailer. Two different circuits in the charger/converter
 

shadowsteve

Solar Enthusiast
That’s what I meant
You can do however you’d like to

I like independent brake battery systems. Always have but that congealed for me the year I worked for a utility trailer dealer.

Ymmv
A utility trailer has no house batteries as built. Same with a hauler deck, boat trailer, etc. If they have e-brakes then they need a battery pack. Not the same as an RV trailer. I think this has usurped the OP's original questions and taken his thread off track though so best to start a new thread if anyone wants to discuss it further. Apologies to the OP :)
 

smoothJoey

SmooJo
The connection to the left side of the switch is from the charger portion of the unit. The right side is the 12v feed to the trailer. Two different circuits in the charger/converter
That is not awesome.
Jayco is burning through their complimentary good will chips with me.
 
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shadowsteve

Solar Enthusiast
That is not awesome.
Jayco is burning through their complimentary good will chips with me.

How exactly do you expect it to be connected? With the cutoff switch open the trailer is depowered for 12V but the batteries can still charge. If you don't want the batteries to charge then the breaker in the panel will control that.

Jayco has no "good will" chips with me but this is Progressive Dynamics wiring instructions. You can look up the PD4590 manual if you want to confirm. Jayco didn't just make this stuff up. Maybe you should look at how your RV is done if you think this is incorrect.
 

smoothJoey

SmooJo
How exactly do you expect it to be connected?
My first objection is with the labels on the drawing.
Its not clear and that is an unnecessary fail.
Second, I want my battery disconnect switch to isolate my battery from both charge sources and loads.
 
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12VoltInstalls

Solar Addict
Not the same as an RV trailer. I think this has usurped the OP's original questions and taken his thread off track though so best to start a new thread if anyone wants to discuss it further. Apologies to the OP :)
No kidding?! Who’d a thunk?

OEMs do stuff or don’t do stuff to make a profit. If the improvement doesn’t suite you don’t do it. You are not obligated to affirm my opinion, I’m not obligated to affirm yours, and I have no need to discuss it further.
usually coach folks to just add a small lead acid battery and isolate the running gear system from the house system
smoothJoey wrote in response to EricR, the OP who asked a question

Not so far off topic
 
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BretS

Solar Enthusiast
If the manufacturers ship a trailer with the breakaway system tied to the installed battery system why are you changing this situation when installing a replacement battery system? The battery technology should have no bearing on how the system is wired for this function.
I agree... I have my breakaway fed from my LiFePO4 bank... I don't get what everyone's issue is with that??
 

12VoltInstalls

Solar Addict
I agree... I have my breakaway fed from my LiFePO4 bank... I don't get what everyone's issue is with that??
Is it also fed from your vehicle 7-pin?

That’s the start of issue
Do what works for you if you deem it safe

I prefer separate brake systems when we put high power batteries and SCCs into our RVs
 
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