If you see my last post, I was talking about lithium titanate, rated for much higher C rates.
It is a VERY rare engine that pulls anywhere close to 800A… most gasoline engines are in the 150-300 range. Most diesels are in the 350 to 600 range. My huge v8 IDI high compression navstar diesel takes around 550 so I doubt any exceed that often… what is needed is low fade high duration cranking. The ability to sustain cranking long enough to build heat to start a big diesel. Load the glow system up, AND run the starter. It’s a tough chore for many batteries. Lithium easily handles the capacity and duration, but cannot handle the amperage, THROUGH a BMS. High C rate lithiums can do it. Most LFP cells are rated at 2C max. With a 280Ah cell that’s over 500A, plenty for most starting. Headways are good for 10C, so easily handle the amperage, just not through a BMS. And only LTO can handle much cold weather charging…
I have an old 7.3 powerstroke, im in the same boat as you. I know the glow plug system draws 300a alone, which is a chore itself! Unfortunately my clamp meter only reads to 400a, so I won't be able to find out.
www.oilburners.net
www.picoauto.com
www.thedieselstop.com
Most diesels have a glow time, then a start sequence.300A ... didn't realize it was so much, but I'm finding references to about 25A per plug, 200A for eight.
Glow plug current draw.
Finally got around to getting a Digital Current/Voltage meter. With the shunt on top, it's good for up to 200 Amps and 200 Volts AC/DC. With that meter I can finish doing my GP testing with the GP controller and 8 GP's I made a year or so ago. Stay tuned for futher updates, if I can make a video...
Glow plug - voltage and current
The purpose of this test is to check the glow plug voltage and current to ensure correct operation.
Glow Plug Current Draw?
I have GMC K2500 with 6.5 turbodiesel.
I should check it next time with clamp ammeter.
"draws 300a alone"
You use glow plugs alone, then after they shut off use starter alone, correct? So never both at once?
I would have thought 4x 280 Ah could deliver several "C" for seconds or minutes, or for a big engine 2p4s with 560 Ah.
I'm still thinking of putting battery & inverter in my truck. Might do a cheaper 12V system (rather than 48V). I would want to have self jump-start capability. K2500 is supposed to have 2x 800 CCA batteries in parallel. I've used 700 Ah Optimas, now Oddessy. My hope is 280 Ah LiFePO4 could start it if needed. Would think even if that is abusive, would be OK for occasional use (unlike your replacement plan.)
Obviously you would connect starter bypassing BMS. BMS could disable solenoid at low battery.
But you need to prevent high voltage disconnect which would blow alternator diodes. What you might do instead is shut off regulator (easier said than done for internal regulator.)
Current into a circuit equals return current to the source.
... but bad connections and such certainly can increase resistance which would increase current...
Exactly. Resistance builds up heat which is expelled through connections and through wire. Does the heat just magically appear?
You are to easily satisfied
No, increased resistance equals decreased current at a fixed voltage (Like from a fixed12v source).
In order for the current to increase due to a bad connection the Voltage at the source would have to increase..
Learn something new every day!
