42 replies to this topic

[Jon R]

That leaves the OTHER white wire in this picture. I'm a bit puzzled over that one. Is that the wire you have wired/taped together with the red one it was joined do in this pic? Looking at the wiring diagram, the only place two wires are shown like that is at the Main Battery, and Aux battery +ve posts. Since we are IN the camper (The auxilliary system), this should be the Aux side of the picture. BUT, that red wire goes to a breaker we confirmed as connecting to the TRUCK (MAIN) battery. Or am I missing something????

If we’re looking at the area where the isolator was installed and the wiring is like my 2021 Grandby was from the factory, one white wire is connected to the hot bus of the 12 volt dc fuse block, and the other is the positive wire from the original truck connector jacketed 3 conductor wire which was white positive, black negative, and green running lights.

Edited by Jon R, 11 November 2023 - 09:01 PM.

[Jollyrogers]

Jon, that is how my 2015 Hawk was wired also.

[Ben_1987]

Thanks for the help all. I tested the wires at the separator and I assumed correctly that the single wire on top was to the battery and the one on bottom was to power the fuse box. Turns out my problem was a grounding issue. I followed that step in the original directions a little closer and based on feedback from others in their replies, and everything seems to be working as intended. I moved the main ground from the input of the DCDC negative and moved it over to the negative bus bar. I then sent a wire from the negative bus bar to each of the negative ports in the DCDC. This brought power back to the camper and everything now seems to be working. I'll probably still remove that wiring I fastened together at the battery separator to remove the extra connection and redundant breaker - but I'll do this at a later date.

 

Thanks again,

[Jollyrogers]

good deal that you figured it out!!!

[Ben_1987]

Ben,  This is looking mighty fine.  A few things:

 

1) That big negative cable by the brake booster in the engine bay... grounding to the body is not ideal.  Can you add to the length of the ground wire to go to a battery post?  Worst cast, add another fat wire from that ground to the battery?  You are asking for ground problems with using the body/frame to carry that much current

 

2) Re: 100% SOC - The shunt will have a setting for "Synchronize" to reset the SOC.  I would put the batteries in a no draw situation and let them charge overnight to make sure they are really full up, and then synchronize the battery monitor.

 

3) Make sure all the charging settings are the same for all devices.  I use 14.4V charging and 13.4 float for my Victron/BB gear.  The only exception is my ACDC which I set to 13.2 resting so that it sits at about 65% SOC when plugged in.  

I just realized I never responded to this, but based on your recommendation, I changed the truck side of the truck to camper ground so it was grounded through the battery and not to the frame. I don't think I ever posted a photo. I also syncronized the SOC monitor but will probably do this again and check all of the PV charger, DCDC charger, and shunt settings now that things seem to be working. I have never seemed to get great watts out of the flexible solar panel so that might be something I check at a later date. I seem to never get more than 100 watts and its a 200 watt panel.

[Ben_1987]

I cleaned up the wiring a little bit and added a disconnect to make it easier for me to disconnect and pull the battery if I need to. I also removed that funky ring connection that I had after the DCDC install. On another note, regarding some poor solar performance last summer, I contacted renogy about the lower wattage I was seeing from my solar panel (max maybe around 70-80 watts with 175 w panel). They ended up warrantying my panel and sent me another 175 watt flex panel. I tested both in the roof and rear solar plugs when I received the replacement and saw about the same watts from either panel. Not sure why I had poor performance in the past (probably due to being further north and trees?) but may try things again this summer after some of my recent rewiring work. Now that I have two 175 panels that presumably work fine, I would like to put both on my roof and run in series through the existing roof connection which would run through the victron mppt 100/30. Any problems with two 175 watt panels on the roof in series running through the stock plug to the victron mppt?

 

 

[Vic Harder]

. Any problems with two 175 watt panels on the roof in series running through the stock plug to the victron mppt?

 

 

Ben,

 

Nope.  To be absolutely clear, your MPPT is rated at 100V input at 30A.  350W total is what you have for panels, and as you have noticed, that's highly optimistic.  Even if you had 360W/12V = only 20A.  And most higher power solar panels only put out 40V or less so your good there too.

[Jon R]

Nominal specified PV power for the MPPT 100/30 is 440 watts, and there’s no reason you can’t overpanel it as long as you stay within the PV array voltage maximum limit of 100 vdc. I have two 200 watt panels into the same MPPT controller and I have never maxed out the output. Even if you did hit the maximum the MPPT controller just limits the panel current by raising the input load voltage the same way it does when optimizing output.

[Ben_1987]

Thanks guys

[Jon R]

I just realized that, while Vic and I both assumed you were asking about the MPPT input capacity, on second look it appears you were really asking about whether the FWC wiring could handle the current from two 175 watt panels wired in parallel and connected to the roof connector.

On my 2021 Grandby I believe the wires are 10 awg, and I have my two 200 watt panels wired that way. Because when the panels are generating 50% or more of their rated levels their output voltage to the MPPT is 25 to 30 volts, the current from both panels totals under 20 amps. The 10 awg wire is more than adequate for that current.

The conservative way to check wire size adequacy for a PV array (for simple wire heating, not voltage loss for long runs) would be to use the short circuit current of the array in sizing the wire. The 10awg wire is adequate when checked this way as well.

Edited by Jon R, 02 February 2024 - 12:40 AM.