Chinese Diesel Heater, powering the thing.

[fpgt72]

I have one of these things in my shop, and it actually works quite well.....save one issue.

I have a small 12V battery, Not this one but one of the same size


as well as a lead acid "lawn mower" battery. The diesel heater will work just fine off of these batteries no issue at all.

The diesel heater sits about 10' from the solar battery bank. My charge controller has a 12v out that I use for lights.

The diesel heater will not run off of the 12v out from the charge controller. As I understand things the heaters will draw 10+ amps when starting up then calm down a bit, figured perhaps it will not support that kind of output.

Wire direct into the bus bars, still no joy.

Diesel heater comes up with an error that says not enough voltage. Ok, checked voltage on the wire coming out 13+v depending naturally. Still the same error. I am thinking perhaps it is the size of the wire, 12 too small? Went to 10, same error, angry I went to 2 same error.

And yet perfect function when the battery is 1' away.

Deeply puzzled.

Any suggestions on this.

 

[Skypower]

Check the power output when you are actually trying to power it up. You may find that open circuit voltage is not the same as under load. Insufficient, or bad battery?

 

[fpgt72]

Check the power output when you are actually trying to power it up. You may find that open circuit voltage is not the same as under load. Insufficient, or bad battery?

I left that part out, sorry.

I can hook the volt meter inline and see the voltage, sits above 13v the entire time. It really has me puzzled.

 

[hugemoth]

Check the voltage at the heater itself at startup. If it's an all in one unit check the lugs on the back to see if there is a loose connection on the inside. These heaters can draw up to 140 watts during startup and shut down.

 

[JJJJ]

These heaters can draw up to 140 watts during startup and shut down.

Sounds like an initial surge.

 

[Rednecktek]

You need a larger battery, the BMS on that battery is likely capped at 1c or 10a which is too little for that 12-14a the diesel heater needs to fire up its pump, fans, and glow plug. The lead acids can output that kind of power for the startup, but the little guy is just trying to work too hard.

Also, that little battery probably doesn't hold enough juice to get you through a night unless you're on the lowest setting the entire time. For reference, running it on high for 24 hours uses just shy of 1Kwh, or just under 85Ah. It's not much, but it does add up over time.

 

[JJJJ]

If you follow other threads on this topic @Rednecktek has a tremendous amount of experience and knowledge regarding diesel heaters.

 

[fpgt72]

Sounds like an initial surge.

I put an analog meter in line and watched the amps climb up to over 20a. ON A 14g WIRE....then shutdown.

On the wire roughly 1' long it will climb to 1/3 that.

What I have done is basically give up. I have that small battery that I will connect during startup and shut down. Then during its running I have a switch that will remove that small battery and it will run off the "big" battery bank.

I think you and the other poster is spot on, the current is HIGH, on the long wire. Why I went to the really large wire, with the same results.

The connection is soldered directly to the board.

 

[OffGridForGood]

One of the (few) places I still use a Lead-Acid battery - the shop backup diesel heater.
To keep the L-A battery ready for service, I bought an automotive battery maintainer and pluged this into a circuit from the solar. As long as I have power on, the battery maintainer is keeping that L-A battery charged and ready to go. Lead-Acid likes to sit long periods at full charge. seems to work for my set up.

 

[Rednecktek]

Hitting 20a on that wire is a sign that the heater is dropping the voltage really, REALLY low and compensating by drawing a LOT more amps trying to compensate for it. Yup, that little battery is too small.

Another option is to set your charge controller to the lead acid settings and just leave both batteries in parallel. You'll only get the LFP up to about 90%+- charge but you'll have the extra capacity of both batteries AND enough amperage to fire up that heater every time.