Battery fuse blew?

Freep

Solar Addict
Got me? I’m also wondering if the fuse holder being plastic was the real problem. As the wire didn’t seem but slightly burned and the fuse didn’t crack, just turned darker. Perhaps I shouldn’t use a plastic fuse holder?
You don't know if running a microwave in your own rig for 30 minutes is something that is likely to happen? Have you ever used a microwave?
 

HRTKD

Boondocker
@JonL , the way your batteries are wired together is probably less than optimal. Go to the link below, from the resources section of the forum. Go to section "3. Battery bank wiring". It will show you better ways to wire up multiple series/parallel batteries.


The recommendation from Battleborn for the 300 amp fuse came from 6000 (surge) watts / 24v * 1.15 = 287 amps and they rounded up to 300. That's a bit high in my opinion.

For the battery fuse, the general recommendation here on the forum is to use a Class T fuse, not ANL.
 

JonL

Solar Enthusiast
@JonL , the way your batteries are wired together is probably less than optimal. Go to the link below, from the resources section of the forum. Go to section "3. Battery bank wiring". It will show you better ways to wire up multiple series/parallel batteries.


The recommendation from Battleborn for the 300 amp fuse came from 6000 (surge) watts / 24v * 1.15 = 287 amps and they rounded up to 300. That's a bit high in my opinion.

For the battery fuse, the general recommendation here on the forum is to use a Class T fuse, not ANL.
Thanks, as I’m still learning. This is my second solar system as the first was lead acid and a much smaller system. I’ll find class T fuse – thanks! 👌
 

jwelter99

Solar Enthusiast
  • Size wire for the load requirements
  • Size fuse to protect the wire
  • Use good components
  • Pay attention to connections on high current contacts
It looks to me that the fuse folder either was not properly fastened on the fuse or wire on that one side leading to high resistance and heat.

Also whenever I see gold plated car stereo type power fittings I get worried as they may work for short transient loads "when the bass goes off" they typically are not adequate for long periods at higher current like you get in an energy storage bank.

Victron suggests CNL for the Multiplus but that is a carry over to AGM battery systems. For lithium Class-T is really the best option, especially for 24V and higher systems. But what you are seeing is not signs of fuse arcing due to too low of AIC but overheating due to poor contact.
 

Freep

Solar Addict
This is for a house. And yes I use the microwave daily.
So you don't know if it is reasonable or likely to run a microwave for 30 minutes in your own house even though you use it daily.....um..... You should probably make sure you have a smoke alarm and a fire extinguisher by your electrical setup.
 

JonL

Solar Enthusiast
Update: well I’m back up again and I think I found out what the real problem is. I believe the wire connections are too short and are heating up faster than everywhere else! I also realize that since it’s been down a couple of days there was a surge of energy from the stored panels. But still this area was the hottest by far.
In the photo where I circled the wire connections, you can see they’re the shortest wires of my whole system. So I’m going to switch out a few wires and make a few others much longer in order to see if that helps!
 

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smoothJoey

Baltimore Oriole
The components?

Sorry, what?

The compression lug could be improperly crimped to the wire.
The flange nut may not be torqued tightly enough.
The terminal and lug mating surfaces may be pitted and/or oxidized.
The mating surfaces may not be clean.
Etc...
 
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HRTKD

Boondocker
Well after I hooked everything up and flipped on the solar panels, the surge from the heat was only at those points that I circled. So what else would it be?

Bad crimps? Bad connections? Recheck your crimps by pulling on the lug as hard as you can. A solidly crimped lug isn't going to come off.

How many amps were you pulling through that circuit? I know what we think is being pulled, which is around 83 amps. But what does your shunt say?

Can you provide a link to the common bus bars you are using? Do I see a crack in the base of the positive bus bar?

Nit picking here, but the fuse should be between the battery and the switch, not between the switch and the common bus bar.

If you put just one wire between the battery and the positive bus bar, does that wire also heat up?
 
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