could the lithium batteries used in EVs be used in place of lead/acid batteries in regular cars?

[80251]

Title says it all. The lithium batteries used in EVs seem to be much more reliable than the lead/acid batteries found in ICE vehicles. Do they have +12V lithium batteries that you could swap for a lead/acid battery? Or would the entire charging system have to be overhauled as well?

 

[USAFRet]

Title says it all. The lithium batteries used in EVs seem to be much more reliable than the lead/acid batteries found in ICE vehicles. Do they have +12V lithium batteries that you could swap for a lead/acid battery? Or would the entire charging system have to be overhauled as well?

There is a relatively new type of car battery that is replacing the old school lead acid.

AGM - Absorbed Glass-mat
https://www.interstatebatteries.com/blog/what-is-an-agm-battery-and-whats-the-big-deal

My Mini requires one.

 

[BFG-9000]

There are LiFePO4 starting batteries that are drop-in replacements for more common sizes of lead-acid batteries available right now if your car will never encounter freezing temperatures.

Charging a LiFePO4 battery at high speed in subfreezing temperatures will cause immediate damage. All EVs using such batteries have battery heaters and will not allow charging to begin until those batteries have warmed to ~40F. This is why you see all of those news reports of EVs "stranded" at the charger but apparently not charging--all of the charger current is redirected to the heaters and if they had waited long enough before calling the tow truck then charging would've begun.

Dropping a regular LiFePO4 battery into your alternator charged car means either the battery would be destroyed in freezing weather or the battery's BMS would disconnect itself if charging is attempted, which in a modern car would fry all of the car's electronics from voltage spikes (the battery is required to smooth the dirty output of the alternator).

Two battery technologies: Lithium titanate, commonly referred to as LTO (Lithium Titanate Oxide) and Sodium-ion can charge at lower temperatures without damage (to subfreezing -20C or -4F) but are currently about double the cost of present LiFePO4.

AGM lead-acid is not a direct interchange with flooded lead-acid because of different charging setpoints, and normally you have to "register" a AGM battery to the car if it didn't come with one, or do hardware mods. For example it's pretty popular to modify the voltage regulator on Toyota Truck alternators to allow this since AGM is nonspillable (which is why Amazon can ship those but not conventional flooded lead-acid)

 

[drivinfast247]

Title says it all. The lithium batteries used in EVs seem to be much more reliable than the lead/acid batteries found in ICE vehicles. Do they have +12V lithium batteries that you could swap for a lead/acid battery? Or would the entire charging system have to be overhauled as well?

There are plenty drop-in replacements already out there. Give google a try.

 

[80251]

So basically I can't use either AGM or lithium batteries unless the alternator is designed to work with them?
Is it possible to get aftermarket alternators that work w/AGM or lithium batteries?

 

[USAFRet]

So basically I can't use either AGM or lithium batteries unless the alternator is designed to work with them?
Is it possible to get aftermarket alternators that work w/AGM or lithium batteries?

Whats wrong with your existing battery, or a same-type replacement?

 

[80251]

I'm tired of replacing lead acid batteries every three years. I'm also tired of having to maintain them (i.e. topping them off w/distilled H2O).

 

[BFG-9000]

If you live in a place like Hawaii or Florida, then you could just drop a LiFePO4 battery in right now because there is very low risk of cold weather. Otherwise for a motorcycle you could use a surprisingly affordable sodium-ion battery, or if you have deep pockets and need a group 24 battery even a solid state one. But lead-acid performs very well at a good price for starting applications without any deep-cycles--there's a reason EVs come with one lead-acid 12v battery even if they have 480v or more in back.

You can actually just drop an AGM in place of a flooded battery but it may have a lower than expected lifespan due to insufficient charge voltage, unless you get particularly lucky and your car just happens to supply enough (which is a real possibility if you have to top-off a flooded battery frequently) or can be programmed to do so. Otherwise you would add a "diode mod" to adjust the voltage a little.

But that may not be necessary because there are some flooded batteries with the same type of VRLA and venting system as AGM batteries use to prevent water loss. Normal flooded lead-acid batteries have regular caps (which may be hidden under a sticker but are there + vent around the edges), while VRLA are completely sealed/plastic-welded except for a vent tube attached to a labyrinthine maze where water can recombine and be recovered instead of lost. These look exactly like AGM batteries but there may be small clues such as a green Delco eye which reveals it's actually a flooded type. So just look for batteries that do not claim to be AGM yet are clearly impossible to top-up + have a vent attachment for trunk-mounting.

Real AGM batteries of course do deliver more amps (from the greater surface area) + have much higher vibration resistance and don't have shorting problems from shed plate material (both from the fiberglass mat mechanically separating the plates). And seems like a deal at only $20-30 more, but those are for the Calcium-Lead models. If you really want an AGM battery that lasts 10+ years then you have to choose one that advertises 99.99% pure lead to reduce internal corrosion, and those cost more.

Flooded lead-acid often dies from an internal short in one cell. Normal use and especially deep discharges result in shedding of active plate material off--and it doesn't all get recoated back onto the plates when charged. If enough accumulates at the bottom of the cell, then you get a short across and fast self-discharge. Some manufacturers like Exide intentionally do not supply enough free space below the plates so the battery won't last much beyond the warranty period, so instead choose a brand OEMed by Johnson Controls (Clarios/Delphi/Varta) like Walmart's EverStart, or East Penn/Deka.

I don't usually buy AGM unless the car originally came with one, because I replace car batteries every 7-8 years before they go bad to avoid problems, and both cheap AGM and flooded lead-acid last that long for me in a mild climate.

 

[USAFRet]

I'm tired of replacing lead acid batteries every three years. I'm also tired of having to maintain them (i.e. topping them off w/distilled H2O).

Buy better batteries.
Got a new one for our 2018 Subaru yesterday. 7 year warranty.
And that replaced the original from 2018, so....6-7 years.

And sealed. No adding water.

 

[drivinfast247]

So basically I can't use either AGM or lithium batteries unless the alternator is designed to work with them?
Is it possible to get aftermarket alternators that work w/AGM or lithium batteries?

Pretty much any vehicle built in the last 15 years will work just fine with a AGM battery without modifications.

 

[80251]

Forget lithium then AGM here I come!