183 replies to this topic

[Utah]

My camper is a FWC Hawk Shell.  Manufacturing date is March 2015.

 

[regarding - "I have no idea what the other coiled wire with split loom is"]

The only wire in the picture with split loom over it is the wire (pair) from the rear wall solar panel connector. 

The larger black/white wire coiled pair is the OEM wire for battery connection (which I do not use).

The other very thick black wire is 2 Ga wire that runs to the truck battery neg terminal (the companion 2 Ga red positive is not shown in the picture).

 

Thanks.

[ntsqd]

I have made several of those jumpers over the years, they're handy. I've also made such a jumper with a momentary switch in the middle of it to use for the remote turning on or off of a circuit. Or for bumping the engine over when running the valve lash.

 

For simple voltage testing I find myself reaching for one of these: https://www.summitra.../parts/apt-7760 Holding the metal barrel and touching anything grounded completes the test light/buzzer circuit. No ground wire whose alligator clip pops loose just when you manage to contort yourself into the perfect form to be able to reach the wire in question.

[Vic Harder]

My camper is a FWC Hawk Shell.  Manufacturing date is March 2015.

 

[regarding - "I have no idea what the other coiled wire with split loom is"]

The only wire in the picture with split loom over it is the wire (pair) from the rear wall solar panel connector. 

The larger black/white wire coiled pair is the OEM wire for battery connection (which I do not use).

The other very thick black wire is 2 Ga wire that runs to the truck battery neg terminal (the companion 2 Ga red positive is not shown in the picture).

 

Thanks.

2awg for battery wires... good stuff!

 

Looks like you already have the signalling and battery wire for a Victron shunt in there too.

 

Yes, if the right hand side are in fact the rooftop PV panel wires, then those would go to a future MPPT input.

 

Do you have any unconnected or coiled wires under the sink? Sometimes those are the rear solar wires.  Otherwise, the wires in the loom are likely the rear solar connectors.  AND, if you buy a portable kit with its own solar controller, then yes, they would connect directly to your battery and shunt.  Beware of polarity issues with solar connectors.  Some are known to be wired in reverse.

[Jon R]

My camper is a FWC Hawk Shell. Manufacturing date is March 2015.

[regarding - "I have no idea what the other coiled wire with split loom is"]
The only wire in the picture with split loom over it is the wire (pair) from the rear wall solar panel connector.
The larger black/white wire coiled pair is the OEM wire for battery connection (which I do not use).
The other very thick black wire is 2 Ga wire that runs to the truck battery neg terminal (the companion 2 Ga red positive is not shown in the picture).

Thanks.

I see now that you were pointing at what you believe is the plug itself on the left side rather than the wire. I didn’t read carefully enough before.

[Utah]

Thanks for the helpful responses.

Vic -
Yes, with this project I will reconnect my Victron shunt and BMV-712. Also, my Hawk is a shell (so no sink).

So, then there is no compelling reason not to cut and modify the wire on the left coming from the rear wall external plug-in connection point?

I am thinking I could modify that wire now for two purposes:
(1) I could run new wiring with connection directly to my battery (positive) and shunt (negative) and use that external connection point as an option to charge my battery using a Noco Genius 5 amp charger that I have (will be a slow charge rate - but gives me another option for charging).
(2) In the future if I decide to get a portable solar panel I could use it to plug in the portable solar panel (being mindful of correct polarity) and it would be pretty much ready to go.

Does that make sense?

[pvstoy]

Solar wiring:

 

https://fourwheelcam...t-solar-panels/

 

 

[Vic Harder]

Does that make sense?

Yes, it does.

[Ruffinit]

Hi everyone,

Thank you all for the amazing work and excellent documentation. You’ve created a phenomenal resource. 

I’m also interested in upgrading my AGM to a LiFePO4. I’ve been following this thread with great interest. 

My ATC camper came with a AOPEC (12V, 140 A) smart battery isolator. 
The truck is a 1996 Toyota T100, so surely a ”dumb” alternator. 

Paraphrasing what Vic said:

 

“Variations

If you do not want to charge the truck from the camper . . then you might want to add a DC-DC charger into the mix . . because an older truck with a “dumb” alternator will . . happily charge your camper batteries. . . now that I have LiFePo4 batteries . . I added a DC-DC charger to LIMIT the charging current to a nice stable 30A.”

 

“If you want to charge the truck from the camper, then you can’t use the DC-DC charger wired like this.  Instead, you will want to use an Automatic Charge Relay (ACR).  I use the Blue Sea ML-7622.  . . “

 

I’m in this second category: my starter battery is connected to my camper battery through my AOPEC isolator. 

My question:

Does the ACR provide the necessary current limit for a “dumb” alternator when charging a LiFePO4 battery?

Can I (Should I) leave the AOPEC and add a Victron DC-DC charger to limit the current?

My limited understanding is the AOPEC will allow 140 A (and the Blue Sea allows 500 A) >> 30 A

Or will the DC-DC prevent the ACR from functioning?
 

Thank you in advance for your comments. 
-Bruce

Edited by Ruffinit, 21 March 2023 - 11:43 PM.

[ntsqd]

The isolator and a DC-DC converter are; very, very roughly; parallel type components.

 

I am unsure of what you want the system to do. I'd say let's start with what you've listed above and work towards the goal of what you want the system to do.

Edited by ntsqd, 21 March 2023 - 11:49 PM.

[Vic Harder]

Hi everyone,
Thank you all for the amazing work and excellent documentation. You’ve created a phenomenal resource.
I’m also interested in upgrading my AGM to a LiFePO4. I’ve been following this thread with great interest.
My ATC camper came with a AOPEC (12V, 140 A) smart battery isolator.
The truck is a 1996 Toyota T100, so surely a ”dumb” alternator.
Paraphrasing what Vic said:

“Variations

If you do not want to charge the truck from the camper . . then you might want to add a DC-DC charger into the mix . . because an older truck with a “dumb” alternator will . . happily charge your camper batteries. . . now that I have LiFePo4 batteries . . I added a DC-DC charger to LIMIT the charging current to a nice stable 30A.”

“If you want to charge the truck from the camper, then you can’t use the DC-DC charger wired like this. Instead, you will want to use an Automatic Charge Relay (ACR). I use the Blue Sea ML-7622. . . “

I’m in this second category: my starter battery is connected to my camper battery through my AOPEC isolator.
My question:
Does the ACR provide the necessary current limit for a “dumb” alternator when charging a LiFePO4 battery?
Can I (Should I) leave the AOPEC and add a Victron DC-DC charger to limit the current?
My limited understanding is the AOPEC will allow 140 A (and the Blue Sea allows 500 A) >> 30 A
Or will the DC-DC prevent the ACR from functioning?

Thank you in advance for your comments.
-Bruce

Yes, your T100’s alternator will be happier if you limit the current draw with a DC-DC. The DC-DC also provides “intelligent” charging, vs just dumping current into the battery.