avslash
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You will get an error light if you pull the BMS sensor. Tried several ways to work around that, and was never successful.
Higher output alternator?
- Thread starter jlach993
- Start date
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As long as the lithium battery can safely be charged with around 100 amps, the charge voltage can be anywhere from 13.8v to 14.6v and the lithium can be fully charged directly from an alternator.
PLEASE NOTE, many lithium batteries can NOT tolerate such CONSTANT high current charging.
The problem with using a lithium battery, be it as a cranking battery or as an auxiliary battery, or both, they will "out smart" the BMS in new vehicles.
This is because lithium batteries have a constant 13.3v voltage for 80% to 90% of there discharge cycle.
When the vehicle's BMS "sees" this higher than normal voltage, it acts as if the battery is fully charged and causes the alternator voltage to drop.
From this point until the lithium battery is near fully discharged, the vehicle will be powered from the lithium battery, and not from the alternator..
I have been testing direct charging of lithium batteries for about two years now and they not only work perfectly in vehicles WITHOUT SMART alternators, they dramatically improve the lifespan of the cranking battery.
There is more to this but it can be done and done safely with the right lithium battery.
Thank you.
Yea, there are many vehicles that have lithium batteries but they have the proper factory BMS’s. An AGM vehicle won’t have this set up for a different battery chemistry. If you’re car has an AGM already, I’d be curious which lithium battery would be a direct drop in to charged by an alternator.
This only applies if the vehicle has a SMART alternator and is the reason I asked if the LR4 SMART alternator function can be turned off or disabled.
If you can defeat the SMART alternator and have a constant voltage, then there is no reason you can not use lithium batteries.
I wonder if the GAP tool could have a function to disable the SMART function.
This would make life so much easier, but to my knowledge, this can not be done on Land Rovers.
Some Fords can have the SMART alternator function turned of with a gap tool.
New VWs can have the very same connection djkaosone suggested disconnecting on the LR4, and with the VWs, you not only turn off the SMART alternator but you also permanently disable the STOP/START function, and that is a big bonus.
A number of Asian makes can defeat a SMART alternator by cutting a single wire connected to the back of the alternator.
None of the above makes generate error messages.
avslash
Full Access Member
I have wondered about adding a resistor to the BMS sensor so that a constant voltage is presented to the ecm, and thus fool it into always providing whatever charging voltage we want.
My electrician buddy said its doable. I was going to do this where I simply stick the resistor into the the 2 prong wire and find the correct resistor that'll trick the system to give the proper voltage I want. I'm pretty sure anything bewteen 14.3V-14.7V is perfect.
I ended up getting a dc-dc charger for my secondary battery and got rid of my traditional battery isolator. I'm pretty happy with the new setup. If anyone is wondering, F60 behind the glove box is an instant ACC On/Off with the push Start/Stop button.
I've done this before I used to go on my off road trips to get a constant 13.8V charge and it will trigger my battery isolator to close for charging my secondary battery. Otherwise, voltage will drop and open the battery isolator, and my secondary battery and accessories die.
I get a warning about Charging Fault.
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