Hot battery cable

jbwells · Mar 17, 2024

Hi team,

Yesterday when I turned the sauna on in my gym the power went out......I went to the solar shed and saw that the battery breaker for inverter 1 had tripped....also noticed that the battery cable going into that breaker looked hot. I'm using 2 6500ex's and 6 eg4 batteries......Even when I'm using 2000w sauna and split duct ac I shouldn't be going over any of the capacities for my solar setup.......I noticed that the main battery cable is getting hot and the battery breaker for inverter 1 looks a little blackened compared to the shiny silver of the inverter2 battery input......Any ideas? Bad battery crimp?

SparkyJJO · Mar 17, 2024

Bad crimp or (more likely) loose nut.

FilterGuy · Mar 17, 2024

I suspect there are a couple possible issues.

1) the 'hot' battery cable looks a lot smaller than the othe cables on that fuse. Is it undersized?
2) The darkened connector and the darkened cables could be due to a bad connection or a bad crimp.

wpns · Mar 17, 2024

The other crimps look hexagonal, the ones on the bad wire look like a single bump?

So yeah, either bad crimp or poor torque on both ends of that cable?

HighTechLab · Mar 17, 2024

Nice bus bar - but why not run a jumper from breaker 1 in the e-panel to breaker number 2 (stacked) then a cable down to your batteries?

Also seems like a lot of current for the gauge. might want to double check the wire sizing coming off the bus bar.

Mattb4 · Mar 17, 2024

That almost transparent insulation on the battery cable gives me pause. I had a problem with a battery cable getting hot with similar insulation. It turned out that the wire inside of it was not the size it was listed at. Do you trust the source of your cable?

seneysolar · Mar 17, 2024

Mattb4 said:
That almost transparent insulation on the battery cable gives me pause. I had a problem with a battery cable getting hot with similar insulation. It turned out that the wire inside of it was not the size it was listed at. Do you trust the source of your cable?

Looks like CCA wire, car audio stuff?

Order up some new pure copper cables, with good crimps. Check out windy nation

Sennen · Mar 17, 2024

Windy Nation or Temco for some quality wire. Can also use thhn if you want that kind of struggle

FilterGuy · Mar 17, 2024

Slightly different topic:
Running wire through a knockout without a grommet or something to protect the cable is concerning and certainly not to code:

I made the same mistake a bunch when I first got started, but as I learned more I stopped doing it. Luckily, I never had an issue but if the edge of the knock-out ever pierced the wire it could be a 4th of July fireworks moment.

timselectric · Mar 17, 2024

Looks like the conductor is carrying more current than its capable, safely.
The conductor is overheating and the heat is causing expansion and contraction at the connection. This loosens the connection. Which creates more heat in the next cycle.
Use a better quality conductor of adequate size. (Oversize if possible)

jbwells · Mar 17, 2024

Wow! So much great advice! Thank you so much.....Ok I'm going to try some new cables from Windy Nation and get some grommets installed. Will update if it fixes the problem so others can reference this thread in the future. Thanks again.

Hot battery cable

jbwells

New Member

Attachments

SparkyJJO

(un)Certified Arc Generator

FilterGuy

Solar Engineering Consultant - EG4 and Consumers

wpns

Solar Joules are catch and release

HighTechLab

AKA Dexter - CTO of Current Connected, LLC

Mattb4

Solar Wizard

seneysolar

Solar Enthusiast

Sennen

Solar Enthusiast

FilterGuy

Solar Engineering Consultant - EG4 and Consumers

timselectric

If I can do it, you can do it.

jbwells

New Member

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