Battery Fuse(s)??

[War Eagle]

For reference, this is what the 40A "battery fuse" looks like in our 2017 21. It would be pretty hard to miss, if you have one. Like others have mentioned, I carry a spare but have never needed it.

[War Eagle]

Originally Posted by War Eagle

For reference, this is what the 40A "battery fuse" looks like in our 2017 21. It would be pretty hard to miss, if you have one. Like others have mentioned, I carry a spare but have never needed it.

I should have noted that the fuse normally has a rubber cap covering/protecting it, but I removed the cap to show the fuse for the photo (you can see the cap tucked under the nearby wire).

[marant]

Thanks for the photo, War Eagle. The 2010 does not have a fuse, but I think I will install one when I install the new series connector. Does anyone know if it makes a difference if it is installed on the series connector, or must it be on the positive lead into the trailer? Seems to me any overload would be reflected in both sets of wire.

[padlin]

Put it as close to the battery post as you can on the positive cable that goes from the batteries to the converter. No need to protect the short battery to battery cable as long as it's of sufficient gauge.

[tdf-texas]

Originally Posted by marant

Thanks for the photo, War Eagle. The 2010 does not have a fuse, but I think I will install one when I install the new series connector. Does anyone know if it makes a difference if it is installed on the series connector, or must it be on the positive lead into the trailer? Seems to me any overload would be reflected in both sets of wire.

Interesting since you mentioned this. For the 17', since the batteries are physically separated with a wire running from one battery across the trailer to the other battery, a catastrophic fuse should be between the two batteries and directly connected to the positive terminal of the first battery in the series.

This would protect both the 6v interconnect wire and the positive 12v wire from short circuit faults. See attached drawing.

[tdf-texas]

The previous drawing would not work if you had an inverter as it requires a 200 amp fuse. In the case where a inverter was installed, a 200 amp fuse and 60 amp fuse would be installed as shown.

[marant]

Anyone have suggestions on a fuse block to attach to the battery terminal?

[John in Santa Cruz]

Originally Posted by marant

Anyone have suggestions on a fuse block to attach to the battery terminal?

this with a suitable battery connector on one side, and a splice to the existing wiring on the other. this holder is good up to 60A fuse, and has 6 AWG wiring

https://www.amazon.com/Bussmann-HHX-.../dp/B000CZ2Z92

[rubicon327]

Originally Posted by John in Santa Cruz

this with a suitable battery connector on one side, and a splice to the existing wiring on the other. this holder is good up to 60A fuse, and has 6 AWG wiring

https://www.amazon.com/Bussmann-HHX-.../dp/B000CZ2Z92

marant: This is the exact one I just purchased to add a fuse near the batteries on our 2010 19. Haven’t gotten around to installing it yet.

[John in Santa Cruz]

btw re things like fuse holders, beware of no-name Asian stuff on amazon/ebay/etc, their wire gauges aren't correct. I got some stuff that was supposed to be 10 gauge, but was much closer to 12, I asked the vendor, "Oh, this is CHINESE wire gauge, not AWG" ... i was less than impressed.

[marant]

Originally Posted by John in Santa Cruz

this with a suitable battery connector on one side, and a splice to the existing wiring on the other. this holder is good up to 60A fuse, and has 6 AWG wiring

https://www.amazon.com/Bussmann-HHX-.../dp/B000CZ2Z92

Thanks, John. Just ordered it.

[lieb]

The solution is correct (soldered connections and larger guage wire). I had a similar problem. What is going on is "I squared R" losses. Ohms law: E = I*R and power law P = I*E (E being volts). If you do the usual math, you end up with P = I**2 * R and in your case you had zero power. In my case, by the time the power got to the propane detector, it was 11 V after I had the batteries replaced.
The problem is at 6.3V, you are talking about a lot of current affected by the resistance. Note it is half as bad with a 12V battery. This is why your solution of a larger guage wire and soldered connections fixes the problem. You should also use larger size connectors and put some shrink wrap on the wire to connector to keep the dirt/water out.
Those battery boxes on a 17B are outside and behind the wheels, a very hostile environment for electrical stuff. Also clean the connections and then give them a good spray with battery terminal protectant.

[tdf-texas]

Originally Posted by lieb

The solution is correct (soldered connections and larger guage wire). I had a similar problem. What is going on is "I squared R" losses. Ohms law: E = I*R and power law P = I*E (E being volts). If you do the usual math, you end up with P = I**2 * R and in your case you had zero power. In my case, by the time the power got to the propane detector, it was 11 V after I had the batteries replaced.
The problem is at 6.3V, you are talking about a lot of current affected by the resistance. Note it is half as bad with a 12V battery. This is why your solution of a larger guage wire and soldered connections fixes the problem. You should also use larger size connectors and put some shrink wrap on the wire to connector to keep the dirt/water out.
Those battery boxes on a 17B are outside and behind the wheels, a very hostile environment for electrical stuff. Also clean the connections and then give them a good spray with battery terminal protectant.

Good post Jim! As you have been a member of the forum for over six years and only 14 posts, it would be great to hear from you more often.

My personal take is that electrical connections should be - mechanically crimped, soldered, and heat shrinked. My experience has been that the wire fails before the connection will if done this way.

[marant]

I am in awe of the knowledge you all have.
Thanks again.

[John in Santa Cruz]

soldering really big battery cables is NOT the best way to go, crimping with the correct sort of heavy duty hex crimper is. its almost impossible to solder like 4 AWG or fatter wire, the copper carries the heat off faster than you can pour it into the wire.

[Eggscape]

This thread has been an interesting read.

Next month I will be doing a post on how and why I hooked up my batteries like this using a circuit breaker and plug.

[tdf-texas]

Originally Posted by John in Santa Cruz

soldering really big battery cables is NOT the best way to go, crimping with the correct sort of heavy duty hex crimper is. its almost impossible to solder like 4 AWG or fatter wire, the copper carries the heat off faster than you can pour it into the wire.

I wouldn't recommend soldering large gauge cables either. I have used Cadweld to join large gauge cables and that works well. Kinda expensive though.

http://www.technoprotection.com/uplo...g%20manuel.pdf

When I made up my large gauge inverter cables, I used welding cable, a compression crimper, and heat shrinked - makes a good gas tight connection and keeps dirt and grime out.

Mike's trailer doesn't have an inverter so the battery cables are 6 AWG or less. Those I would compression crimp, solder, and heat shrink. I bought this a while back and have been very pleased with it.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

It will crimp terminals down to 12 AWG with compression - much better than a standard wire crimper.

[Vermilye]

I guess I'm lazy. While I have a crimper that will go up to #4 wire, for inverter cables I have them made to order. I had Genuine DealZ build the #2/0 cables with the wire color, terminals & heat shrink I wanted. While more expensive than making your own (although buying a hydraulic crimper for one time use adds a lot to the overall $) Genuine DealZ does nice work, ships quickly, and lets you choose wire color, although limited to red or black for the largest sizes.

[marant]

Finally got it done. Thanks everyone, particularly tdf


(With photo, I think)

[Bilbo]

Originally Posted by tdf-texas

I wouldn't recommend soldering large gauge cables either. I have used Cadweld to join large gauge cables and that works well. Kinda expensive though.

http://www.technoprotection.com/uplo...g%20manuel.pdf

When I made up my large gauge inverter cables, I used welding cable, a compression crimper, and heat shrinked - makes a good gas tight connection and keeps dirt and grime out.

Mike's trailer doesn't have an inverter so the battery cables are 6 AWG or less. Those I would compression crimp, solder, and heat shrink. I bought this a while back and have been very pleased with it.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

It will crimp terminals down to 12 AWG with compression - much better than a standard wire crimper.

Hello TDF-Texas, I was wondering if you could provide more info, or an updated link on the compression crimper you linked to in your post. Seems your Amazon link now points to a pink buggy.
Thanks