Do you have any data on how much electricity your unit uses?

Yesterday was my first time running the unit with the new truck batteries and before I turned it on the voltage was at 12.6v and after running it for 40'ish minutes the voltage was down around 10v after turning the key on and activating the glow plugs which I know is a great way to kill my FICM so I need to do some more testing today and monitor/record the voltage and see what's what. I'm thinking I may need a third battery to use this heater properly and to prevent damaging my FICM.

And ambient temp was -20c/-4f and after running the unit for 40 minutes it got the coolant temp up to 35c/96f.

Thanks

 

Heater alone takes 50-60Watt.
Did you connect the heater to the blower motor? Then it depends on the fan speed. This power consumption is added on top.

On cold days, the heater always runs for 30-40 minutes here. It works perfectly fine. No starting issues.

 

Not connected to the blower motor.

After 30-40 minutes of running your unit do you know what your battery voltage is before starting the engine and after the heater has done it's shut down cycle?

 

I see 12.2-12.5V.
I think your batteries are the issue

 

The batteries are brand new and not even used till yesterday. Brought them home 2 weeks ago, trickle charged both of them then put them into the truck and have sat there since while I monitor the voltage to see if there was any parasitic draw with all my electronic add-ons unplugged, which there wasn't. After trickle charging the batteries were at 12.89v and over the 2 weeks the voltage settled to 12.62v which seem reasonable seeing as the temp has dropped 20 degrees since the batteries were put into the truck.

Today I'll top up the batteries then let em sit for 5 hours then with my multimeter hooked up I'll run the coolant heater for 30 minutes set to the highest setting(80c)and see where the voltage is at once the heater has shut down. If the draw is drastic then the only thing I could think of would be the glow plug staying on the whole time, but that would most likely burn it out if running for 30 minutes straight so at this point I dunno!

 

Are these both the same heaters????

 

Is yours a 5KW device, too?

 

We should compare the ampere values.

 

No. Mine is a Chinese clone.

 

It's listed as a 5kw unit.

 

Chinese listed means nothing.... pull out an ammeter.

 

I don't have one of those. Will my multimeter suffice?

 

It only makes 10A

 

Sorry, I don't understand.

 

Your device will max measure 10ampere.

With 20A you should be good:


do you have a clamp multimeter?