36v to 12v

crossy

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What's the output voltage when the heater drops out? Does the heater show under-voltage or some other error?

And please, what is the INPUT voltage to the converter when the output is under load?
 

MisterSandals

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I see a couple things in your pics:

First is the temp controller that it looks like you are using as a cutoff contractor to (from?) your 36V-12V converter.

I don't think these are meant to handle that many amps. I was using one for a couple years to run sead tray heaters and it stopped working on a 5A load yesterday. I added a 100A digital contractor and it works great (surprisingly).

Try taking the temp controller out of the equation (take the 2 left wires and twist them together) to identify or rule this out.
Screen Shot 2023-01-24 at 9.12.29 AM.png

Probably not related to this issue but if this breaker gets warm or trips before it should, replace it with a quality breaker immediately. Otherwise replace it soon, its going to be trouble with a 1500W inverter (sooner than later).
What brand is this? $15 Chinese knockoff?

Screen Shot 2023-01-24 at 9.10.43 AM.png
 

Rednecktek

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I know that box!

OK, so you're getting good voltage in, what's the output no-load voltage? It should be 13.something at least. If that converter is doing what it's supposed to at 30a then you're right and there's "Something Strange" going on.

I know, not much of a help but at least it's good to know you're not crazy.
 

Kamaleon91

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Lol thanks guy's I'm still trying to figure it out I will change the breaker. I just purchased an adjustable buck converter I might be able to add it as just a dedicated 12v line for the heater I have to figure this out its driving me crazy
 

Vigo

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If you have a multimeter with min-max, that has a way to disable the auto turn-off feature (i have one that you have to hold a button while turning it on to get it to stay on indefinitely) you could use that to verify that the input voltage never drops too low. But based on the amount of battery you have powering a 300-400w converter i dont actually expect that to be the issue.
 

Kamaleon91

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I can't explain why this is happening doesn't make any sense at all I have more than enough power I've seen them heaters run on a motorcycle battery
 

Rednecktek

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I have 3 and I've done multiple measurements... average is 13.6a to start up peak dirty, 12.8a for a clean start, 44w after full start on the 8kw unit, 33w on the 5kw units after full start, both running highest setting.
 

Bud Martin

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Too bad that OP does not have 12V 30A load that OP can try to see if the Buck Converter can handle it or not, and we also do not know what the surge current the Buck converter can handle.
 

Kamaleon91

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If I have to purchase something that can better supply the proper power then I will like I said I purchased an adjustable buck will that do the trick?
 

MisterSandals

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If I have to purchase something that can better supply the proper power then I will like I said I purchased an adjustable buck will that do the trick?
I reread from the top and my gut feel is the batteries are the issue.

How hard would it be to pull the batteries out so you can isolate them?
I suspect they are not wired in a balanced manner and only a couple of the batteries are getting fully charged and fully drawn on for loads.
 

12VoltInstalls

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I just tested the voltage just after the buck converter under load with the diesel heater and it was holding a constant 12.23v but the heater still drops out in a few minutes in
What size cables/wires? Or did I miss that?
Post25 pic they look small-ish but I’m on a phone…
I reread from the top and my gut feel is the batteries are the issue.

How hard would it be to pull the batteries out so you can isolate them?
I suspect they are not wired in a balanced manner and only a couple of the batteries are getting fully charged and fully drawn on for loads.
That’s reasonable.
His description sounds a bit like tired fla but of course they are not.
 
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