I am just puzzled ...

[Winterbagoal]

Originally Posted by AJMike

I think that the OEM wet cells were designed for people who plan to camp at sites with shore power and were only intended to provide enough power for them to get from one camp site to another with, perhaps, one night in-between with no short power. When we found how much we preferred dry camping and especially boondocking the power turned out to be insufficient unless we were willing to run our generator. Given how much my wife hates the sound and smell of it there was not much choice.

We did consider AGMs for a while but it just seemed like a better solution to go with the Lithium and, even with all of this extra charger pain I still think it was the best decision for us.



Thanks.

I think cost of them might have played a teeny role in Winnebago choosing them over their newer offerings in the newer models, AGM or Lithium standard or optional are available now. Not offered when we ordered our Navion. You too?
I think the lithium option is probably going to be the best overall option for some time, considering all the factors. Price always scares people, but if you "do the math" it works out about equal, or maybe even better from a bang for the buck perspective. For me, anyways. (Unless the batteries outlive me, and that's always a possibility).

[BobC]

The difference in square mm between 5 and 6 AWG is minor. 5 AWG is 16.8 sq mm, while 6 AWG is 13.3 sq mm. Diameter-wise, the difference is 0.51 mm.

https://www.engineeringtoolbox.com/a...uge-d_731.html

I can't see that's going to make much, if any difference, in your situation. The charger is only going to put out 30A, so I'd check out what you need based on the actual length of your run:

https://www.bluesea.com/support/arti...r_a_DC_Circuit

[DavidM]

Interesting thread, but maybe you should concentrate on physics for your answer rather than the manufacturer's fractured advice.

When you connect a charger to a battery, the charger senses the battery's voltage at the charger's terminals, not the battery's terminals which is what really counts. Other charging sources like alternators have a remote sense wire but I have never seen a charger with one.

So it is important to keep the voltage drop low, to about 0.2 volts so that the actual voltage delivered to the battery terminals is close to what the charger is seeing. There are wire sizing tables and programs that will figure the voltage drop based on current, wire size and wire length.

Let's assume that it is 5' from your charger to your battery. That requires 8 gauge wire to stay under 0.2 volts drop. Then let's assume it is 17 feet (5 meters), that requires #3 gauge. So it looks like Victron allows maybe 0.3 volts drop which leads to #5 gauge.

Then you have to consider the voltage drop from the alternator to the Victron. I have never seen any recommendations so let's keep it to 0.2 volts as well.

So here is what I would do if your distances are short- 10' or less: use #6 gauge wire which will fit into the set screw holes and be done with it, knowing that the voltage drop is reasonably low. And yes it should always be stranded wire. Solid wire is used in buildings that don't vibrate.

David

[Goodspike]

Originally Posted by DavidM

There are wire sizing tables and programs that will figure the voltage drop based on current, wire size and wire length.

I posted a website above that does that.

https://www.calculator.net/voltage-d...s=30&x=57&y=13

[AJMike]

Originally Posted by Winterbagoal

I think cost of them might have played a teeny role in Winnebago choosing them over their newer offerings in the newer models, AGM or Lithium standard or optional are available now. Not offered when we ordered our Navion. You too?
I think the lithium option is probably going to be the best overall option for some time, considering all the factors. Price always scares people, but if you "do the math" it works out about equal, or maybe even better from a bang for the buck perspective. For me, anyways. (Unless the batteries outlive me, and that's always a possibility).

We bought 2 years ago and at that time Winnebago was offering a Lithium Option for one of the Class Bs, I think the ERA but I am not sure. As far as I know it was not available for the Fuse at that time and certainly no one offered it to us when we were going through the purchase. On the other hand I did not know then how much we would enjoy dry camping/boondocking so had it been offered to us I am sure I would have declined.

I did not hear about the Winnebago Lithium upgrade for the Fuse when I decided to upgrade to Lithium and the price would probably have put me off had I known. We spent $2400 for the BB batteries and the install of them plus the Renogy charger. The charger itself cost another $200 so the total cost was about $2600, about half of the Winnebago upgrade.

However were I to go through this again I would be sorely tempted to get the Winnebago upgrade for a couple of reasons. It includes 250AH of power, not 200 AH, it includes what Winnebago calls the "alternator control module" (which sounds like a BIM to me) and it includes all of that with its vehicle warranty. I am more than happy with the BattleBorn batteries, but less than happy with the Renogy DC-DC charger and it would be nice to know that the whole thing was covered by a manufacturer warranty. Yes, BB warrants their batteries for 10 years, and Renogy warrants their charger for one year, but I have been trying to get the Renogy 40 amp charger fixed now for 5 months and I still don't know what the issue really is, or whether or not Renogy will fix it.

The Renogy 20 amp charger is working just fine now, but seems a bit small fro 200 amps of battery and I worry that it will just take too long to fully charge them after some extended dry camping.

[AJMike]

Originally Posted by BobC

The difference in square mm between 5 and 6 AWG is minor. 5 AWG is 16.8 sq mm, while 6 AWG is 13.3 sq mm. Diameter-wise, the difference is 0.51 mm.

https://www.engineeringtoolbox.com/a...uge-d_731.html

I can't see that's going to make much, if any difference, in your situation. The charger is only going to put out 30A, so I'd check out what you need based on the actual length of your run:

https://www.bluesea.com/support/arti...r_a_DC_Circuit

The OUTPUT side of the charger has a very short run length, perhaps 5 feet, and it is not the issue. 8 gauge wire would probably be enough. The issue is the INPUT side. I measured today and while I did not crawl under the RV I did measure how long the run would have to be to be run down under the RV, across to the passenger side, back to the coach step, up to the cabinet holding the charger and then to the charger and all of that is about 16 feet.

The charger is rated as being about 87% efficient and having a continuous output of 430 watts. Given an 87% efficiency that means that the input power is almost 500 watts. I don't know what the input voltage is, but if it is 12.4 volts then we are talking about approximately 40 amps from Ohm's Law. If it is 12.2 volts then the current would be a bit higher. The table you referenced lists that as 6 gauge, so perhaps that is enough. I will give it a try since I did buy some 6 gauge wire from HomeDepot.

[AJMike]

Originally Posted by Goodspike

I posted a website above that does that.

https://www.calculator.net/voltage-d...s=30&x=57&y=13

That looks very helpful but I don't know how much of a voltage drop the unit can take. If it truly is 0.2 volts then I do need 5 gauge wire. What I found interesting is that when I brought the 6 gauge wire at HomeDepot and checked to see if it would fit into the set holes I found it not only fit, it fit with room to spare. I now wish I had bought some 4 gauge wire, if only a foot, to see if it would fit as well.

I asked about 5 gauge wire at the store but only got blank stares and the comment that they carried 6, 8 and 10 gauge. When I asked about 4 they said that yes, they did have that as well, but no one seems to carry 5 gauge in the local stores.

[DavidM]

I think that the output side voltage drop is much more important than the input side, as the B2B device turns whatever input voltage it sees to a higher output voltage so it can charge correctly. For 15' and #6 gauge and 30 amps you will have 0.37 V drop which doesn't seem bad at all.

You can always go to #4 gauge and pull a few strands out for the last inch so it will go in the set screw hole and get it down to 0.23V.

David

[AJMike]

What I ended up taking away from all of this is that different tables and/or calculators give varying results. Some tables indicate that 6 gauge is OK, others that 5 gauge (and hence 4 gauge since I can not find 5 gauge) is needed.

I don't know what the most important thing here is - heat or voltage drop - or if they are both equally important. But there is one thing here that might also have an effect. Of the 16 feet or so of length for the INPUT side of the charger, 13 feet or so is 4 gauge wire. If 3 feet is 6 gauge then the voltage drop from that small section might not be enough to cause an issue.

A bit of calculation using the Voltage Drop Calculator that Goodspike posted gives some interesting results.

16 feet of 5 gauge wire, 12.2 volts, 41 amps yields a voltage drop of 0.41 volts.

13 feet of 4 gauge wire + 3 feet of 6 gauge wire, 12.2 volts, 41 amps yields a voltage drop of 0.36 volts (0.26 + 0.1), less than the drop from the all 5 gauge wire. Perhaps the 6 gauge wire may be OK, at least for a short trial, to see how it works.

[dkoldman]

Originally Posted by AJMike

If you find it I would appreciate you either posting it or sending it as a PM. In the meantime I will go to HomeDepot and try to see if they have any wire that seems appropriate and will fit into the set holes. I will also do a search on eBay and see what I can find.

Not sure if application intended is suite but it is copper and stranded 4 gauge. 5 ft each color?

https://www.ebay.com/itm/4-Gauge-Wir....c100005.m1851

4 gauge sold by foot (black)

https://www.ebay.com/itm/4-Gauge-AWG...8AAOSwwNVTud7B

and 4 gauge red

https://www.ebay.com/itm/4-Gauge-AWG...4AAOSwFAZTuecn

[AJMike]

Originally Posted by dkoldman

Not sure if application intended is suite but it is copper and stranded 4 gauge. 5 ft each color?

https://www.ebay.com/itm/4-Gauge-Wir....c100005.m1851

4 gauge sold by foot (black)

https://www.ebay.com/itm/4-Gauge-AWG...8AAOSwwNVTud7B

and 4 gauge red

https://www.ebay.com/itm/4-Gauge-AWG...4AAOSwFAZTuecn

Thank you for the links.

[orangeminnie]

We've found that the Victron terminal connectors work MUCH better when ferrules are used. #6 is difficult to fit in without it, let alone #5. The ferrule crimps to a square, which fits into the connector wonderfully. For 30A, we jump to a gauge larger than #6 at the first junction point, unless the run is only a few feet.

[winnie32v]

Just thinking....
Would it be reasonable to open up the wire hole(s) using a drill bit????
Then maybe the thicker guage wire would fit into the holes.!!!!!

[AJMike]

Originally Posted by orangeminnie

We've found that the Victron terminal connectors work MUCH better when ferrules are used. #6 is difficult to fit in without it, let alone #5. The ferrule crimps to a square, which fits into the connector wonderfully. For 30A, we jump to a gauge larger than #6 at the first junction point, unless the run is only a few feet.

How far do you run 6 gauge to the first junction? The total input run for us is about 16 feet, all of it 4 gauge except for the last 3 feet.

I have never used my crimping tool on a ferrule so I don't know. Do they all crimp to squares when a crimping tool is used? Or do you need some special ferrule or some special crimping tool?

[orangeminnie]

Originally Posted by winnie32v

Just thinking....
Would it be reasonable to open up the wire hole(s) using a drill bit????
Then maybe the thicker guage wire would fit into the holes.!!!!!

No..................

[AJMike]

Originally Posted by winnie32v

Just thinking....
Would it be reasonable to open up the wire hole(s) using a drill bit????
Then maybe the thicker guage wire would fit into the holes.!!!!!

Perhaps. But I would think is that doing that would not only void my warranty but perhaps destroy the wire hole or damage the ability of the set screw to hold the wire. It is certainly a step I would prefer to avoid.

[orangeminnie]

Originally Posted by AJMike

How far do you run 6 gauge to the first junction? The total input run for us is about 16 feet, all of it 4 gauge except for the last 3 feet.

I have never used my crimping tool on a ferrule so I don't know. Do they all crimp to squares when a crimping tool is used? Or do you need some special ferrule or some special crimping tool?

Ferrules take a dedicated crimping tool. The ones I've seen and/or used, crimp to a box/square on the larger wires, and more or less round on the smaller wires. Complete kits very cheap on Amazon.

[AJMike]

Originally Posted by orangeminnie

Ferrules take a dedicated crimping tool. The ones I've seen and/or used, crimp to a box/square on the larger wires, and more or less round on the smaller wires. Complete kits very cheap on Amazon.

Thanks. I will look into that.

[Winterbagoal]

"ferrules" implies iron based metal sleeves encapsulating copper stranded wire. I would imagine the iron reduces conductivity and adds a lttle resistance, as well?
Are there copper ferrules?

[e4services]

they assume the EU standard, and has a different insulation that connection wire.
I would not worry about a short piece of connection wire, if that is what you need, just the long run to the panel is best to use solar wire.