No Battery Power - troubleshooting help

danwrona

I'm troubleshooting an electrical issue and have eliminated all possibilities that I'm aware of. I'm handy enough but not an electrical expert, so I'm looking for help considering other possibilities.

2023 TAB CS-S Boondock
We replaced the basic factory 64 Ah marine battery with a Weize 12v 100Ah AGM, but we're getting no power to the 12v system
The only change I made was disconnecting/reconnecting and switching in a new battery box
There are no physical signs of any damage or issues
All fuses are intact (two in-line blade fuses in the battery box, blade fuse at the controller, and all fuses in WFCO panel)
Nothing happens when we turn the battery disconnect switch on
Power doesn't even seem to be getting to the switch, but I'm not sure how to test it 
I was able to test shore power with a wall adapter (15a circuit), and lights, fan, and pump work 
I'm not sure quite how to read the Victron settings, but it does not appear to be reading/recognizing the battery - screen shots attached for reference

• Am I missing a fuse?
• What else might be the cause? 
• Are there any other testing procedures you would recommend?
• What other information would be helpful to diagnose?

Thanks for any help you can provide

skibug

When you say the fuses are intact did you perform a continuity test using a multimeter or just visually inspect them? I would recommend a continuity test. 

Grumpy_G

Do you have a voltmeter at hand? That would be the best tool to troubleshoot this. 

Not to insult you, but one thing I can think of is that the battery is connected the wrong way around, this causes the reverse polarity fuse in the power center to blow. The solar charge controller will also not recognize the battery. 

Basic troubleshooting: measure voltage between battery posts, measure voltage between battery switch and ground (e.g. the trailer frame, check reverse polarity fuse. 

pthomas745

Show us a photo of the battery wiring.  IF the battery was wired in "reverse polarity", the "battery protection fuse" in the WFCO has blown.  In theory, the fuse at the battery itself should also have blown.  

It is possible that the battery you installed has a very small charge, and the "low voltage disconnect" circuit on the battery management system has kicked in.  You could simply try leaving the trailer plugged in, battery disconnect on, and see if you get any charge at all into it that would "kick start" it back to life.  (See your manual or check the Wieze battery pages for info about the "low voltage disconnect".

And....yes, a multimeter.  Every single "help my battery" post can be sorted out quickly with a meter.

Grumpy_G

Forgot to ask: Confirm you got an AGM battery not a LiFePo battery? As @pthomas745 mentioned the latter type turns off the output completely when the charge gets too low. 

Marceline

Can you post a photo of the connections at the battery? Are you sure that you reconnected it correctly? 

I think that the solar controller should be wired directly to the battery (not through the switch), so it's strange that it's reading zero voltage.

It's odd that there is no 12v power to the camper and also no battery reading in the solar controller as these should be two separate paths (solar controller directly to battery and house connection to battery routed through the switch). 

danwrona

Thank you all for weighing in so quickly.
 
@Grumpy_G No insult taken - don't claim to know what I'm doing, just trying to learn things I've never been exposed to

Responses to some of your questions, working on others:
Yes AGM not LiFePo
Battery was fully charged, currently reading 12.9V with multimeter
No reading from the disconnect switch to ground (frame)
Picture of wiring attached. There's a small chance the green wires are wrong but +/- are correct (working from a bad before picture - I know, novice mistake). 

pthomas745

The battery wiring in the trailer can be confusing.

Two sets of cables on your trailer: one is for the trailer, and the other is for the SAE port (the solar port).

The two cables with the fuses are the "positive" cables, and should be on the positive post of the battery.

The two white cables are the "negative" cables, and should be on the negative post of the battery.

You can see the general idea from the photo below.

Once you get the wiring in the right place, then it will be time to check the various fuses in the WFCO for "battery protection", etc.  Turn the battery switch off while you re-wire.

Let us know how things work out!

PS:  Good for you for having a multimeter!

rfuss928

Thanks for the photo,  I think I see the problem.
The wires connected to the positive post are both the battery connections and those on the negative post are both of the solar connections.
To fix:
Turn off the battery switch.
Disconnect all the existing battery connections
Connect the two white wires to the minus post.  One from each loom.
Connect the two green wires from the red fused lines to the positive post.  One from each loom.
Turn on the battery switch.
All should be good.  I don't think anything has been damaged...

Marceline

That looks wrong to me. The red/green lines are both positive so should both be connected to the positive terminal. The whites are negative. You should probably also double check the fuses in those fuse holders before you reconnect everything.

danwrona

That was it, all's working!

Thank you all so much for the quick help. And mostly for sparing me an embarrassing conversation with a service tech (not to mention the fees). 

I will get pictures before disassembly.
I will get pictures before disassembly.
I will get pictures before disassembly.
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