26BH DC Upgrade

[ve7fet]

This is going to be a long post... but I know there will be stuff in here that some folks will find interesting.

If I've learned one thing in owning different RV's... the manufacturers have no clue when it comes to electrical. It is quite sad, with all the money we spend on these things, that they can't even do the simple stuff right.

Let's start with some stock photos:





So a few interesting finds, once you start tracing wires, and seeing what they did.

Let's start with the power jack. How many times have you, or the DW run the jack up and hit the limit, and promptly blown the 30A fuse that Jayco wired in to the jack power lead?

Well, pop the cover on the jack, and what do we find inside?



Hey! There's a 20A automatic resetting circuit breaker in there!! WTF?

Why on earth put a 30A fast blow fuse inline, when the jack manufacturer already protected the jack with a circuit breaker?

One 30A fuse holder promptly removed, and wired direct to the battery.


Now, when you dig in to that mess of a junction box, that someone obviously used a drill to drive on all the wire nuts (WAY too tight), pay attention to the grounds.

The TT uses frame ground for return. The ground wire from the battery (was) grounded to the frame in here.

Unfortunately, Jayco took all the rest of the ground wires (white), from some lighting circuits and the TOW VEHICLE HARNESS and wire nutted them to a BARE #14 wire, which they then grounded to the frame through one of the screws in the box.

Now I hope someone realizes how STUPID that is... let me give you a hint... Your #6 battery ground goes to the frame, ok fine. HOWEVER, your tow vehicle ground (for your lights and CHARGING) is grounded to the frame through a piece of #14! Every wondered why you barely get any re-charge current to your battery when your TV is hooked up? Now you know!

Obviously, I'm going all in for my upgrade, so lots of stuff got changed. The frame mounted CB's, gone. The fuse for the jack, gone. The "solar ready connector and wiring", gone.

Back to the grounds. My main frame ground got relocated (due to the installation of a Trimetric), so that just left the remaining grounds in that JB up front. Put ring terminals on them, some No-ox-id A Special grease, and re-attached to the frame:



While I was in there, I also got rid of the wirenut for the TV brake signal, the emergency brake switch, and the TT brake wire. Took all three of those wires and used a proper compression splice and heatshrink to ensure that there is no chance of corrosion here that could affect my brake electrical:




See more in Part 2...

[ve7fet]

Part 2...

Back to the actual upgrade... first, we're getting rid of the single 12V and going with dual 6V in a NOCO dual 6V box.

That involved adding some aluminum angle supports to the stock rails, to allow the NOCO box to be mounted on top:






I went with a 250A Mega fuse and holder at the battery. Used #2 weld that is c-tapped up to #1/0 flex. This gives me some flexibility in the last couple feet for the battery connections, and then 1/0 to the main panel that I mounted in the front passthrough (street side).




So, in the front passthrough, I mounted my new DC charge/discharge distribution panel.



We've got a BEP 701 disconnect on the main positive lead from the battery.

A positive and negative buss bar to terminated connections on.

We have a 400W true sine inverter (it's what I had on hand... might upgrade that later). A Chinese 80A circuit breaker feeding that... again, it was already on hand.

We have a Morningstar Sunsaver MPPT charge controller here to support solar charging. A couple DIN breakers to feed that (solar and battery).

There is a 80A Mega fuse and holder that feeds a #6 running back to the hitch for the new TV charge connection (my truck has an aux battery, and there is a dedicated connector at the hitch for it).

I pulled back the #6 from the WFCO converter under the underbelly, and fed it up in here to terminated on the positive buss bar.

There is also the 500A shunt for the Trimetric.

So, on the negative buss bar, we have all the grounds. There is a frame ground wire (#6, terminates on the frame, just under the passthrough), inverter ground, TV ground, and ground for the solar. On the other side of the shunt, we have the ground that goes direct to the battery negative.

This way, the Trimetric reads ALL charge/discharge current in to the batteries. That is the ONLY connection to the negative side of the battery (if you noticed another wire on the battery picture, that is a temperature sensor for the Sunsaver, not an electrical connection).


Mounted the Trimetric and the Sunsaver meters on the curb side of the master bed, so I can open the door and have a peek at what is going on:




While I was cutting holes, I also added a USB charge port, and 12V DC accessory socket (for powering my CPAP) on the street side of the bed:




The dual 100W Renogy panels on custom folding mounts:



Built custom pigtail cables for those using Anderson SB50 connectors. The Sunsaver will take either a single panel (12V) or I can throw the two in series (about 30V) and get better power transfer to the controller. There is a SB50 mounted on the side of the TT, just under the passthrough door... now we are "Solar Ready".

Oh, and the WFCO has been replaced with a Progressive Dynamics retrofit converter, that actually charges the batteries. If anyone wants a brand new WFCO, I have one for sale.


Still a bit of wiring cleanup to finish, but it is finally coming together.

The 400W inverter is plenty enough to run the TV and the kids electronics. If I need more power, I'll just fire up the Honda.

[GrievousAngel]

I will review carefully. It certainly shows that you have dug into the problems and solutions.

I will return with questions I'm sure.

Thx,

Billy

[GrievousAngel]

Being an electrical guy, I see that you know proper electrical methods and practices. You've done a great job.

Do you feel its reasonable to run the 13,000 BTU AC off grid for short intervals w/o a generator? ~ battery amp capacity and converter/charging sizing? Inverter specs?

I'm looking at a 30A 120VAC system with: WF- 8930/50 Distribution Panel, WF-68100 converter/charger, WF-5100 series sine wave inverter, solar trickle charger, up to a 500A battery system.

Would a 2 x 6VDC battery system be preferred to a 12VDC battery (assumming amp capacity being ~ equal?

I found the CB inside the electric tongue jack as well! My tongue jack also had a glass inline fuse feeding from battery. Was it a 20A fuse?

Do you or should you drive a Cu ground rod when off grid?

Later,
Billy

[GrievousAngel]

Hello ve7fet:

Thanks for your sharing of this information.

First, what are the tongue CB(s) protecting? Are there two? Replace with another brand or size?

What brand, type and group size battery do you suggest? Battery box?

I understand the best wire to use on RV's is 'Boat' listed wire and cable, with only all Stranded Cu wire, terminals, etc.

I propose in Phase One Upgrade:

1. 400 Ahr of Deep Cycle AGM: (2) 6VDC @ 200 Ahr each or (1) 12VDC @ 400 Ahr. OR should invest in a Gel battery system. Would Gel battery technology change if I used 6VDC or 12VDC batteries?

2. Upgrade battery wire to 400 Ahr with Vdrop of 1% @ 40'?

3. Upgrade WFCO converter to WF converter or other brand? I know a realistic charging criteria is needed. Remove current WF converter. I would like Gel charging flexibility in my new converter. Current available for charging, ie. other than 30 A @ 120 VAC?

4. Upgrade DC junction box connections near tongue. Suggestions on terminations and grounding. Replace CB to what brain, type and size based on above upgrades.

Other suggestions important to do in first phase? Would do solar charging in phase Two, so I may need to prepare in Phase One?

I must start soon, as I have no useful battery capacity currently.

Later,

Billy

[GrievousAngel]

I have no front pass-through on my 2018 Hummingbird 17RK? So, where would you suggest to mount the battery charge/discharge components? I think I could mount in a NEMA 12 Box on front tongue ... The curb-side storage is needed for my heavy gear. I also could mount under the queen bed like the hot water and furnace, but nearer center of space. Con: Not in Code Favor - Not accessible quickly. The 17RK is ~ 19' long!

Billy

[ve7fet]

Originally Posted by GrievousAngel

Do you feel its reasonable to run the 13,000 BTU AC off grid for short intervals w/o a generator? ~ battery amp capacity and converter/charging sizing? Inverter specs?

No, I don't think it is worth the money you'll have to spend to make that work. You're going to need at least a 2 if not 3kW inverter to handle the surge current on start, unless you add a Micro-Air soft starter to help with that.

Then, you're going to need a lot of battery, if you want to run it for any length of time.

Much better off with a Micro-Air and a 2kW generator, if you need air conditioning.

Originally Posted by GrievousAngel

I'm looking at a 30A 120VAC system with: WF- 8930/50 Distribution Panel, WF-68100 converter/charger, WF-5100 series sine wave inverter, solar trickle charger, up to a 500A battery system.

I don't know what their inverters are like, but I would stay away from almost everything WFCO makes, especially their converters.

You'll be much happier with a Progressive Dynamics converter, or one of the other specialty brands that actually charge your batteries and maintain them. The nice thing about the Progressive Dynamics is that they make a drop-in replacement for most of the WFCO distribution centers... just change out the converter section and you're done in 20 minutes.

Originally Posted by GrievousAngel

Would a 2 x 6VDC battery system be preferred to a 12VDC battery (assumming amp capacity being ~ equal?

Always. You will get better performance out of 6V batteries in series.

Originally Posted by GrievousAngel

I found the CB inside the electric tongue jack as well! My tongue jack also had a glass inline fuse feeding from battery. Was it a 20A fuse?

Mine had a 30A ATO fuse... which now is gone.

Originally Posted by GrievousAngel

Do you or should you drive a Cu ground rod when off grid?

Later,
Billy

Nope, ground is usually too hard in most campgrounds, and you don't know where they have run services, if there are any.

[ve7fet]

Originally Posted by GrievousAngel

Hello ve7fet:

Thanks for your sharing of this information.

First, what are the tongue CB(s) protecting? Are there two? Replace with another brand or size?

I believe one was on the DC supply from the battery, and the other may have been part of the "solar ready" wiring. Both are no longer required in my application.

Originally Posted by GrievousAngel

What brand, type and group size battery do you suggest? Battery box?

I'm giving the Interstate's from Costco a try, to see how well they perform. Trojan are very popular too.

Use the biggest 6V you can fit in your box. Mine are GC2's.

The NOCO battery box seems pretty well built. I did drill a few drain holes in the bottom well, as the lid has vent holes and wiring holes, so it is not waterproof... and I didn't feel like having to pull out the batteries to sop up the water once it finds its way inside.

I would have preferred to find a suitable aluminum tool box to fit across the tongue and put the batteries and wiring inside, but that just wasn't in the budget.

Originally Posted by GrievousAngel

I understand the best wire to use on RV's is 'Boat' listed wire and cable, with only all Stranded Cu wire, terminals, etc.

I had some surplus #2 welding cable (super-fine strands, very flexible), and some other fine stranded #6 and #1/0, so that's what I used.

Originally Posted by GrievousAngel

I propose in Phase One Upgrade:

1. 400 Ahr of Deep Cycle AGM: (2) 6VDC @ 200 Ahr each or (1) 12VDC @ 400 Ahr. OR should invest in a Gel battery system. Would Gel battery technology change if I used 6VDC or 12VDC batteries?

2. Upgrade battery wire to 400 Ahr with Vdrop of 1% @ 40'?

2x200Ah 6V's is still 200Ah... they're wired in series.

Most of the converters play equally well with flooded or AGM. It is personal preference or budget, more than anything. At least with flooded 6V, they are readily available in most places... AGM would be more of a specialty, if you needed to replace one on the road.

Use the biggest wire you can afford, especially if you are wiring it to an inverter.

Originally Posted by GrievousAngel

3. Upgrade WFCO converter to WF converter or other brand? I know a realistic charging criteria is needed. Remove current WF converter. I would like Gel charging flexibility in my new converter. Current available for charging, ie. other than 30 A @ 120 VAC?

Drop-in replacement Progressive Dynamics is the easiest solution for most WFCO upgrades, in my opinion.

Originally Posted by GrievousAngel

4. Upgrade DC junction box connections near tongue. Suggestions on terminations and grounding. Replace CB to what brain, type and size based on above upgrades.

Other suggestions important to do in first phase? Would do solar charging in phase Two, so I may need to prepare in Phase One?

I must start soon, as I have no useful battery capacity currently.

Later,

Billy

Yeah, dig in to that JB up front, make a wiring diagram before you rip it all apart, and then start cleaning it up.

You can leave the existing CB's, if you need to. I removed mine, as all my protection moved to my new panel.

At the very least, get in there and look at/fix the grounds, and check for other poor connections.

The problem with them spinning on those wire nuts with a drill is they break a lot of strands in the wire from over torque. So, they really should be checked and fixed. Solder and heat-shrink, if you don't have access to something like a T&B c-tap or other compression splicing system.

[ve7fet]

Originally Posted by GrievousAngel

I have no front pass-through on my 2018 Hummingbird 17RK? So, where would you suggest to mount the battery charge/discharge components? I think I could mount in a NEMA 12 Box on front tongue ... The curb-side storage is needed for my heavy gear. I also could mount under the queen bed like the hot water and furnace, but nearer center of space. Con: Not in Code Favor - Not accessible quickly. The 17RK is ~ 19' long!

Billy

Perhaps a custom aluminum box on the tongue that would take the batteries and all the wiring? There may be a concern there with hydrogen off-gassing and corrosion... but anti-ox grease on the connections would probably mitigate most of that.

I'm not too worried about any "code" requirements... this is an RV. Just do good, safe work, and keep the batteries outside.

It depends on how crazy you want to get with re-wiring stuff. If you aren't adding a lot of new components, then you may not need a lot of space.

You could also look at adding something like a 175 or 350A Anderson disconnect to your batteries, and building a heavy cable to plug your inverter in to, if you just need to use it occasionally. Then you can stuff the inverter wherever you have storage, until you need it.

[GrievousAngel]

First I must thank you ve7fet for your very detailed assistance. Sincere thanks. Billy

This is my delima:

If upgrading to: PD9280 converter w/ Charging Wizard Pendant and (2) 6VDC 235Ah AGM Group GC-2 batteries yielding ~470Ah capacity @ 12VDC in tongue battery box.

Option 1) Locate upgraded PD9280 converter near ORM WFCO electrical dist panel at rear door.

Pro: Less weight on tongue; Potentially less wiring; NO additional electrical panel box required; Less cost; Already have adequate space near rear door area next to WFCO panel.

Con: Not real close to battery system, ie. ~20' one-way.

Option 2) Locate new PD9280 converter near batteries on tongue and feed converter output (#2 Cu) to WFCO electrical distribution panel at other end.

Pro: Near battery system.

Con: Additional tongue weight; requires additional panel box (modified tool box); Additional cost.

It appears to me that Option 1 above is most advantageous. what is others opinions on this?

If using Option 1, is the PD9280 converter a excellent choice for the new battery system, ie. (2) 6VDC 235Ah AGM Group GC-2 batteries yielding ~470Ah capacity @ 12VDC? Would #2 welding be more than adequate for the battery run to converter (20' one-way)? The PD9280 battery terminals are rated up to #2 cable. What size battery cables should I use, ie. #2 as well? #2 seems a little small IMHO, but I am not deeply experienced in RV engineering (yet???)! So, 3rd division would be to use 2/0 welding cable then neck-down to #2 at converter end. What brand wire reducer do you recomend? Some are big dollars!

Is it correct to say that the only time the RV is earth grounded is when the 'shore power' is connected? When 'off-grid' there is no earth ground unless a generator is used. Am I correct in this statement?

Enough for now.

Thx,
Billy

[dhunter79]

Originally Posted by GrievousAngel

(2) 6VDC 235Ah AGM Group GC-2 batteries yielding ~470Ah capacity @ 12VDC

Electrical Math is wrong because 6VDC are in series and you don't add Ah, you add volts in series
(2) 6VDC 235Ah AGM Group GC-2 batteries yielding 235Ah capacity @ 12VDC

(2) 12VDC 235ah batteries in parallel would get you 470Ah, you add amps in parallel

[GrievousAngel]

It seems that a RV electrical system utilizing a converter and a inverter could be problematic. Am I correct? It would seem that automatic transfer switch would be required.

How is this accomplished, if its recommended?

Thx

Billy

[GrievousAngel]

Thanks, you're correct. I mistyped. What I think occurs is that when in series, the available ampere storage capacity or stored energy (power) doubles. The key words are 'stored or available '. Like you said the Ah do not double. It's analogous to two capacitors in series. The amount of stored energy doubles if in series.

Taken from another forum: "The confusion here is that volts times current (amps) equals power in watts. Although the amp-hours remain the same by doubling the voltage you have doubled the stored power. Or another way to look at it is you can now draw twice the current and have the same theoretical voltage drop in a given amount of time."

That being said, it is somewhat popular to use (2) 6VDC batteries in series to obtain 12VDC.

Any other comments? This is an interesting electrical concept.

Thx

Billy

[GrievousAngel]

Thanks, you're correct. I mistyped. What I think occurs is that when in series, the available ampere storage capacity or stored energy (power) doubles. The key words are 'stored or available '. Like you said the Ah do not double. It's analogous to two capacitors in series. The amount of stored energy doubles if in series.

Taken from another forum: "The confusion here is that volts times current (amps) equals power in watts. Although the amp-hours remain the same by doubling the voltage you have doubled the stored power. Or another way to look at it is you can now draw twice the current and have the same theoretical voltage drop in a given amount of time."

That being said, it is somewhat popular to use (2) 6VDC batteries in series to obtain 12VDC.

Any other comments? This is an interesting electrical concept.

Thx

Billy

[tjpolsin]

Ah, the choices.
- two small 12v batteries in parallel
- one big 12v battery
- two 6v batteries in series.

look at both the total weight of lead in the batteries you are adding, how thick the lead plates are, how much you want to spend, and what will fit in the tongue battery rails (without mod).

There are huge 12v construction/trucking batteries that fit that have lots of lead with thick plates, but the cost isn't worth it.

A single large 12v battery usually has nearly the same weight of lead as two 6v "golf-cart" batteries, but the plates are thinner.

more lead equal more total ahr capacity. thicker plates provides for more even an complete discharge of the battery.