Fridge to battery?

[Rhythmtone]

These are great suggestions thanks,
It's hard to use the quote feature on my phone but I will try to reply back to the most important things, ad hoc.

I can/will try a 20A in the DC board position, I suppose - installer put a 30A but I can change it back - doesn't really solve the problem though.

Why can't I use a different DC board that had 1-2 circuits for 30A? (For slide outs usually)? Like the Amazon link below:

https://a.co/d/5LLDBd8

It's "Main" fuses are 40A but it gives you 2 slots for 30A devices - this way I can leave the 8AWG run from the fridge to the panel alone, and just upgrade to 6AWG (or whatever) from panel to battery, which probably needs to be done anyway ...

I will try to add more as I think about it, but this seems like the easiest way,
Thanks

To add:
The progressive dynamics and OEM Chinook board (magnatek/parallax?) both have 30A "main fuses", supporting 20A max at each DC circuit - even using either of these boards (haven't decided yet) the undersized run to the battery will still be present, unless upgraded. So we're really taking about 2 problems.
#1 under-rated single DC circuit for fridge
#2 undersized wiring from DC panel to battery (total load)

Changing to the board I linked, from a WFCO unit, at least gives me the grace that the individual DC circuits (2 of them) are correctly rated, for 30A, which solves problem #1.

Problem #2 will be present with any board that I use (currently), working from small to big, I don't see why this wouldn't all work as intended - 8AWG from fridge to DC panel is good, get a DC board that provides supports 30A on a single circuit, upgrade wire from said DC board to battery, which needs to be done anyway it seems ...

Thanks

[Blue~Go]

I took a look at the board you linked. Didn't mean to not include it before, it's just that I would never use any of these style boards, so I'm not familiar with them. I right away don't like them because of the wires just being trapped by screws. Those loosen, and then you get heat and resistance, which no fuse or breaker guards against. I would suggest checking the tightness every few months (or maybe more if you bounce around on dirt roads) (or half the Interstates these days )

I realize they are in almost every RV, and every RV isn't burning down. They are just something I'm not used to (coming from boats) and I don't really like them so when I re-did my DC distribution I naturally used what I'm familar with instead (whole brown box is gone).

I guess if it were me (which it isn't) I'd do the following

1) Just put in a 20 amp fuse and try it. I mean, you would only be using the DC mode when driving right? At that time your voltage will be higher due to the alternator. Oh, nevermind:

Okay, maybe not. I did just look up the watt draw of the DC element for the original fridge that was in my Chinook (RM3663) and it is 215 watts. So obviously whomever installed the fridge you have now didn't bother to consider electrical requirements

2) A solution just for the refrigerator, which would solve both the issue of the undersized circuit board and the crazy undersized (due to length) wire. This would be to run a cable pair from the refrigerator, forward through the existing Chinook wire chase, across the overhead of the overcab (just ahead of the panel that holds the doors on the overhead - is basically out of sight and P-clips can be secured to overhead -- this is how I ran the 8AWG duplex wire for my current fridge, tho granted it only draws about 45 watts), then down behind the driver's side pillar and to a fuse block just before the main positive house bus bar (battery bank).

3) Bonus which isn't directly related to the fridge but will make your whole DC electrical system happier is to run a shorter (and maybe larger) cable from the brown box "output" to the house batteries. This can be run against the wall under the couch (outboard of the water tank) in good loom. The original run is not only just a slim little 8AWG, but it also goes from the brown box, back to the shower wall, out to the outer wall, up the corner to the overhead, forward in the wire chase above the window (!), and then down the driver's pillar. Surprised they didn't take one more lap around the Chinook for good measure For this, if you only run an 8AWG positive cable, fine. If you run a larger cable then add in a jumper from battery neg to frame that is the same size as the new cable. There are holes already in the frame right there to bolt through. But even if you keep the new cable to 8AWG, the new run would be about HALF the length of the original (more length = more voltage drop).

As a side bonus you could re-purpose the original 8AWG wire and terminate it in any location that is useful to you along its path: Driver's side overhead cabinets, floor by driver's side pillar, overhead cabinet on driver's side. That's handy as the original wires that lead up there are smaller and less capable (more voltage drop).

2 + 3 together would make a nice improvement. Of course there's more that can be done (proper fusing! etc.) but it's a start and not too difficult.

If you either keep the original Brown box DC fuse board - or add a larger one of the same type, I would definitely check/tighten those screws on a regular basis. They can be prone to loosening which causes resistance and heat.... and there is nothing that can really protect from that.

[Rhythmtone]

All great advice thanks!

I mostly got everything exposed today, not that easy, haha.

A new run from brown box to battery, behind the couch, seems like a clear win - I may even move the batteries up into the living room, like you did, but haven't decided yet.

Do you remember where the white DC wire (negative) runs after the brown box? I may actually be lengthening that if it terminates closer to the box originally - I forgot to trace that one, for now.

What gauge would be good for this? I was going to go with 6AWG due to cost and installation difficulty, especially if running down to the original battery location in a pair, but I could maybe step up to larger.

For the screws, yes, I understand - I will look at the blue sea stuff, but not sure how much more I want to spend. I was thinking a tiny dab of green loctite might help, we'll see.

Thanks again

[Blue~Go]

All great advice thanks!

I mostly got everything exposed today, not that easy, haha.

I remembe those days. Good on you.

A new run from brown box to battery, behind the couch, seems like a clear win - I may even move the batteries up into the living room, like you did, but haven't decided yet.

It's a bit surprising that Chinook didn't just make a wire chase down there. SO MUCH shorter.

What type of batteries are you going to have? I just ask because flooded cells are not something I would move inside. AGM or LFP I would. In any case, there is much about the battery area in the Chinook that could be brought up to modern safe standards (main fuse! main switch).

If you've been reading my posts in another thread, you already know how I feel about the LVD, so I'll refrain

Do you remember where the white DC wire (negative) runs after the brown box? I may actually be lengthening that if it terminates closer to the box originally - I forgot to trace that one, for now.

Not sure which one you mean, but in general (for the DC system), Chinook used white for ground. There is an 8AWG wire from the brown box to the chassis, which carries the small chassis grounds back through the system (eg the ones on the frame ends at the rear). Maybe that's the one you are referring to?

I would (and did) supplement this with a new chassis ground wire from the house battery negative to the frame, myself. I used 1/0AWG but that's because I ran a 1/0AWG positive for my self-jump-start wire, so I needed to keep everything in that circuit to 1/0AWG or better. If the jump-start circuit is not going to be part of your plan, then even an additional not-quite-so-big wire would be an improvement. Anything. You don't want to end up with a situtation where you have 3/4 of a circuit (or circuits) at a certain wire size but then you forget that little link and it's a bottleneck/weak link.

What gauge would be good for this? I was going to go with 6AWG due to cost and installation difficulty, especially if running down to the original battery location in a pair, but I could maybe step up to larger.

Whether you would want to go larger or not kind of depends (IMO) on your whole battery setup and your expectations for lifespan. I mean, for example, you wouldn't pair the charger that's in the brown box with a set of Lifeline AGM or some nice LFP. The charger is just too dumb, and in the case of AGM, has no temp sense.

But to isolate just this wire, here is some idea:

Sample: 50 amp combined loads, 25' of 8AWG wire (original setup). Voltage drop is a horrifying 15.5%
Sample: 50 amp combined loads, 15' of 6AWG sire (new setup). Voltage drop is less horrifying 5.6%

Sample: 25 amp combined loads, 25' of 8AWG wire (orig.). Voltage drop is 7.4% (ugh)
Sample: 25 amp combined loads, 15' of 6AWG wire (new). Voltage drop is 2.8% (somewhat acceptable)

Upgrade to 4AWG:
Sample: 50 amp combined loads, 15' of 4AWG wire (new). Voltage drop is 3.5%
Sample: 25 amp combined loads, 15' of 4AWG wire (new). Voltage drop is 1.8%

Now in the above scenarios your voltage drop would always be worse than those figures. That's because I didn't count the long (colored) wires to the loads, all the connections, voltage drop over fuses, or the voltage drop of the main wires at the batteries. This was a calculation for JUST that old/new piece of wire, as if it existed in a vacuum.

BG

[Rhythmtone]

New batteries are AGM Duracell Group 31's
New charger is PD4645VL - because it was no extra cost to get the lithium option
Original LVD is gone, by PO - replaced with LR9806 simple disconnect switch, open to advice on this piece, haven't decided yet, but it does work

DC load on the panel is hard to say, but approximately:
15A lights
15A lights
15A range
15A detectors
20A furnace
10A USB accessories
30A fridge - but may l use original 8WG from fridge to panel, then connect to original 8AWG from panel to battery (only for fridge) - this will be a very long run, but keeps the 23A fridge on it's own run - alternatively, fridge goes to new DC board and becomes part of the main load. Also, since I'm not sure where the fridge negative connects, yet, this is still undecided.

It's a good point about total voltage drop and weak links, but obviously I'll have to live with the post-panel DC wire runs, as those would be next to impossible to upgrade in most cases.

Yes, that is the white wire I am referring to - it connects to chassis somewhere, but I haven't found the pathway yet.

The only substantial negative wire in the battery drawer (except a small accessory one) goes straight to chassis, not up into the coach, it's independent, and easily replaceable - but this one doesn't go to the DC panel directly, based on visual inspection.

I am on the fence about disconnecting the old white wire in the DC panel, as the new run to battery, behind the couch, will replace it - but I may leave it connected in case there's something else that uses it, behind the walls, if that all makes sense.

Boost circuit would be nice to keep, the "combiner" is not original (I know about the recall thanks to your other threads) - it is some metal circular one that I still need to identify - seems as if it was installed when the "house party on wheels" stereo modifications were done with the huge amp in the rear, though why they decided to run it all off the engine battery is still beyond me.

More to come, haha,
Thanks again

[Blue~Go]

New batteries are AGM Duracell Group 31's

OK. I felt comfortable moving my AGM bank under the couch (this was back in 2014). I DID completely re-do the DC distribution so it had fusable wire sizes, was all fused, had a main battery switch, etc. There were some really shaky bits in the original setup (not picking on Chinook: RV standards have always been really low, and it was the 1990's and with that context they did better than some - at least it's well documented!)

LR9806New charger is PD4645VL - because it was no extra cost to get the lithium option

Okay, that's a pretty dumb charger and won't be particularly kind to your batteries. No temp comp (critical), etc. But if you either aren't going to be shore charging very often, or you don't mind your batteries not lasting as long as they could it can work.

Original LVD is gone, by PO - replaced with LR9806 simple disconnect switch, open to advice on this piece, haven't decided yet, but it does work.

I looked it up and it looks like a solenoid/switch. So unless I'm misreading it, it's not the same as an LVD (low-voltage disconnect). That said, I think the Chinook LVD didn't disconnect until (IIRC) 11.5 volts. That's so low it's almost useless, IMO. So maybe no big loss, as long as you know what you have now is only a switch (that you turn on and off).

DC load on the panel is hard to say, but approximately: ....

.....It's a good point about total voltage drop and weak links, but obviously I'll have to live with the post-panel DC wire runs, as those would be next to impossible to upgrade in most cases.

This really brings up a larger question. The electrical system is just that: A system. It can be easy to get into a situation where you are replacing this and that component but not really planning or implementing the whole. And that's okay as long as you know that's what's going on and it's okay with you.

BTW, I've re-done the entire DC distribution system in the Chinook, but I have not (nor did I feel a need to) replace any of the original (colored) wires going to the loads. A couple times I removed something and moved it to another wire*, because some of them were pretty long/thin/overloaded (voltage drop); but they all had appropriate fusing at least.

*either a new wire I ran; or eg re-purposing the 8AWG refrigerator wire or the 8AWG previous load center wire. My rig also had a yellow 14 AWG running up each side from behind the brown box (not connected) up to each side of the overcab. I forget what they were marked for but it was something optional to "entertainment" that my rig didn't have. So those were re-purposable. I have 12 ATC fuse positions in the blocks that replaced the 9 in the brown box section; plus another 6 in the Safety Hub (plus 4 Midi fuse positions also in the Safety Hub).

Also, just FYI for future: It's pretty easy to get into the wire chases running up each side of the Chinook inside the upper cabinets. Really the only part that's semi-impossible is where the bundles all run behind the shower stall. That's where the original refrigerator 8AWG came in handy for the passenger side (I ran a new duplex cable around forward for the refrigerator).

Yes, that is the white wire I am referring to - it somehow makes it to negative terminal, but I haven't found the pathway yet

I believe that runs to the frame in the rear driver's side. I circled it in red in this excerpt from the 1999 manual. Chinook ground wires have all been white in mine (except certain purchased components that had other colors in their own pigtail).

Usually you can click to enlarge:

- I can upgrade battery drawer negative to chassis ground wire easily, which seems to be "after" all of these DC runs

There kind of is no "after" in the negative circuit. I mean, it's all one common ground. You do still have to have a full circuit, somehow, for each size of wire, but there is no "after" to my mind.

- I am on the fence about disconnecting this old white wire, as the new run to battery will replace it - but may leave it connected in case there's something else that uses it behind the walls, if that all makes sense.

I would leave it in place and just add another/beefier one from the house negative post/busbar to the frame.

Boost circuit would be nice to keep, the "combiner" is not original (I know about the recall thanks to your other threads) - is is some metal circular one that I still need to identify - seems as if it was installed when the "house party on wheels" stereo modifications were done with the huge amp in the rear, though why they decided to run it all off the engine battery is still beyond me.

I would definitely check into this. Here are the things that were wrong with my original Chinook installation of this circuit:

1) Wire was not large enough to fuse to the amp draw of a jump start. It was unfused at the start battery. That's not cool. So many places for that long wire to potentially short out.

2) Surepower was recalled for catching on fire. But even withhout that, it induced a lot of voltage drop when charging on an already long skinny wire.

3) Fusing at the house bank was wholly inadequate for that circuit. Also no proper AIC rating.

4) There was no control at all over the charging parameters when charging while driving (and no way to shut it off, either).

I do think it's worth summarizing that it might be worth thinking over (not saying you already aren't) the big picture. Do you want it safe(r)?
Do you want to take better care of your batteries in terms of charging them through solar, shore power, or the alternator (or just replace every couple years)?
Do you want to aim for lower voltage drop for your appliances or etc.?

All of the above?

Not that you can't do it bit by bit, but sometimes that could lead to re-doing. Just something worth thinking about.

[Rhythmtone]

I'd say I'd like all of the above, to do it "right", without spending a massive fortune, a small fortune is okay, haha - redoing is a nightmare - the workload and it being all torn apart, etc - time is way more on my mind than money ATM, which is why I've even gone this far, haha. As in, put in time now, not tear it apart again - It would be different if things were easier to access, but they aren't, haha.

I understand about " there is no after" regarding the entire circuit - I just meant physically and to point out that there are multiple spots that might need to be looked at - as you said, no point in upgrading just one section of the circuit(s).

Can you give me a charger recommendation then? The Internet certainly recommended PD4645, haha, but I see your point about thermal sensing.

More to come, thanks!

[Blue~Go]

I have to run, but I'd say for starters, have a look at the currently going "Batteries" thread we have going. You may not want to wade through the whole thing, but by the last couple of pages we have things pretty well ironed out.

Short version: Consider something like a Victron IP22 15- or 30-amp charger. This is fully programmable, and will work in a Smart Network (see below) to give you temp sense plus voltage sense.

Add a Victron BMV 712 battery monitor plus plug-and-play temp dongle for it. Now you have a battery monitor (good!) and you can set the two up in a Smart Network so that the IP22 uses the temp and voltage AT THE BATTERY POST for the charger (and for any future solar or alternator charger such as an MPPT 100/20 or OrionXS).

Physically, since this charger has a "household" AC plug, I would wire an AC receptacle to the "charger" AC breaker (and remove the wires for the PD charger). Because voltage drop is not a big concern on AC wire, you could put that receptacle under the sink area (close), or nearer to the batteries (farther away). Then size the DC wires accordingly to the length of run from the actual charger DC outputs to the battery bank. Better yet, run a separate pair of DC wires for the charger to house batteries (same couch route), instead of "doubling up" on the load wire like Chinook did. There are a few ways to do this depending on personal choice.

If you put your batteries under the couch of course this all gets much more compact and you run less/smaller wire.

Fuse all wires coming off the house bank with a main fuse and switch, and then have branch (DC) fuses that re-fuse as the wires get smaller. See the other thread. Even if you don't want to wade through the whole thing, you could just skim through and look at the diagrams and photos and probably glean some info fairly quickly.

[Rhythmtone]

I understand most of this, haha, thank you so much.

It only begs one more question (for now) - if I get a Victron or that style of charger, and move it, let's say into the battery drawer, for the sake of discussion, and use an AC run to get back to to the AC breakers, that seems like a clean solution.

This would take the charging load off the long DC run, and solve voltage drop one-way, for charging. But NOW, going the other way, powering DC loads, I'm now debating whether is it necessary or prudent to also run new DC wire back to the panel with this layout - it seems that I will be limited by the size and length of the existing WHITE wire at the DC panel (if it's in use), and/or the size/length of any small ground wires at the loads, let's say the fridge or a DC TV, for example. I could upgrade the wire size from battery to panel, and it would be shorter, both things provide better voltage at the panel, but I'm not sure how much this will matter, especially if few or zero loads are grouned to the panel.

To clarify, if any of the DC loads DO use the white wire at the DC panel, I'll be limited by gauge and length from panel to the load, because I'm not replacing that. If they DON'T use the white wire at the DC panel, then I'll be limited by whatever small ground that they do use, elsewhere in the coach. I see why moving the battery and/or running a new DC pair makes sense in theory, but I thought that all loads got negative from the DC panel, which was wrong.

Hopefully that makes sense, thanks for all the info so far,
Dave

[Blue~Go]

I understand most of this, haha, thank you so much.

That's great. I know when it's just a bunch of words it can seem like a slog to visualize.

It only begs one more question (for now) - if I get a Victron or that style of charger, and move it, let's say into the battery drawer, for the sake of discussion, and use an AC run to get back to to the AC breakers, that seems like a clean solution.

In some ways I like the idea of the charger somewhere "indoors," but then the battery compartment is pretty sheltered. And of course going any distance with AC wire is easier (in terms of voltage drop) than DC wire.

But so okay, let's run with that idea (the charger will be down below near the batteries). Actually this is precisely the setup that was chosen in the concurrent battery thread, in case you want to dip in a take a look.

This would take the charging load off the long DC run, and solve voltage drop one-way, for charging.

Yup.

But NOW, going the other way, powering DC loads, I'm now debating whether is it necessary or prudent to also run new DC wire back to the panel with this layout - it seems that I will be limited by the size and length of the existing WHITE wire at the DC panel (if it's in use), and/or the size/length of any small ground wires at the loads, let's say the fridge or a DC TV, for example. I could upgrade the wire size from battery to panel, and it would be shorter, both things provide better voltage at the panel, but I'm not sure how much this will matter, especially if few or zero loads are grouned to the panel.

Okay, so stepping back a little, any device has a "loop" or circuit. So let's take a TV up in the overcab for example. Here is the path:

--House battery positive post
--Looooong skinny positive wire to DC distribution in brown box (fuse panel)
--12AWG orange wire that runs (ha ha, back along the SAME path) through the wire chase above the driver's side cabinets up to the overcab
-- TV ITSELF
-- white negative wire that runs back through the driver's side overhead cabinets and eventually down to the frame rail sort of under the shower (at some point a number of small white wires join up).
-- "through" frame rail up toward battery bank
-- thence through the negative jumper from frame to battery negative post

So does the negative path take a side jaunt up through the white wire to the brown box? It has no reason to. In fact, why is that 8AWG negative jumper even there? (Between the brown box and the frame.) I believe that's only the charger's (PDXXXX) negative return. I mean, you don't need to rip it out, but I don't believe it carries any circuit grounds. Negatives in general don't have any reason to return to a positive fuse block. They just need to get back to the battery negative to complete a circuit.

This is why I upgraded (size) the negative jumper from the house negative battery/bus bar to the frame. It's really ultimately carrying all negative loads.

Have a look at this diagram showing all the chassis grounds (from the 2000 manual but my early 1999 is exactly the same): Click on it to make it larger and more focussed.

Teal colored box:
-- that's the main jumper from the frame to the house battery negative.

Red box:
--110v chassis ground (I forget what this looked like on the brown box end so suss this out. It may be bare copper? At any rate as long as you are not changing the brown box ground wires -- and I don't see that you need to -- it should be fine)
--the 12v fuse panel ground (I believe this is the white 8AWG you see on the front)
--the 12 volt circuit grounds (basically all the driver's side Chinook loads come along the upper cabinets then go down the rear corner and end up here)

Green box:
-- Refrigerator chassis ground (8AWG)
-- Generator chassis ground (I think this is 6AWG)
-- 12 volt circuit grounds (like in the red box above, but this is all the passenger side loads that run along the upper wire chase, down the corner of the closet, and to the frame)

To clarify, if any of the DC loads DO use the white wire at the DC panel, I'll be limited by gauge and length from panel to the load, because I'm not replacing that.

See above, but I don't believe they do. I think it's only the charger in the DC circuit. That said, you can just leave that wire there, as it's not like a positive wire where you don't want to leave any extra "live" wires danging around. (If it were like that, your whole frame would be dangerous.)

If they DON'T use the white wire at the DC panel, then I'll be limited by whatever small ground that they do use, elsewhere in the coach. I see why moving the battery and/or running a new DC pair makes sense in theory, but I thought that all loads got negative from the DC panel, which was wrong.

Right, so as you can see above, all the Chinook loads have their own ground wires that go directly to the frame (some of them combine a bit before they go to the frame - in the rear corners on each side). So the important wire to enlarge is the jumper that goes from the negative house battery to the frame (luckily that's an easy one).

The only other time you would have to think about this is if you were adding NEW positive wires to NEW loads. Then you need to think about hmm but my chassis ground wires are still only the same size as original. What I do is I just don't add any new chassis grounds. Anything new that I run has a positive/negative wire pair, and that negative wire goes right to the negative bus at the house batteries.

Exception would be if, say, I used the original 8AWG refrigerator power wire. I'm not using that for the refrigerator anymore, but I left it over there to possibly use for a new item. No real need to do that on the driver's side, but it's pretty difficult to get wires around the back of the shower and over to the passenger side. So, if I reused that wire for something else, I could also re-use that 8AWG white wire that goes to the refrigerator chassis ground, because Chinook already has that "pair" in place.

So to summarize:

**New charger's AC wires (or the wires to the receptacle you are going to plug the charter into) go to AC section of brown box, to "charger" breaker and other appropriate ground busses (copy existing charger wires).

**You can leave the brown box chassis ground wires in place.

** Enlarge the chassis ground wire that goes from the house negative battery post (or actually this would go to the incoming side of the BMV's shunt, marked "load.") to the frame.

Make sense?