Yikes, sorry to hear you are only getting 3 yrs out of your 12v acc. battery. I just purchased a 2020 Kona EV a month ago and have no issues so far. Not sure if it is OEM battery or newer. I did replace my Ducati OEM battery with a Li-ion made by AntiGravity 2yrs ago. It has been flawless. I do believe they make Automobile replacement Li-ion batteries as well. I would not hesitate to look into them for your Kona.

Don

 

My original 'Rocket' battery still worked perfectly into the 6th year but I retired it and installed an AGM start-stop battery at twice the price of a flooded calcium-lead-acid. Only 1.5 years later I'm seeing slight wobbles in the continuum but fingers crossed it still works fine. But I know what pisses it off and don't do that dumb stuff, like having doors open for more than a few minutes. I monitor it daily with a BM2 voltage logger.

I can't reconcile how a battery can fail after 3 years without external factors. There's always a back story.

 

A bit of the back story: I suspect that last summer when I left the car sitting in my driveway while on a long 5 week trip, the battery missed me and became unhappy and sullen, although it didn't give up for another few months (see my Feb post). I removed the 12V battery from my Kona EV after that post, it read 5V. I used the desulphate cycle on my battery conditioner for about 36 hours. The battery then accepted a charge and got up to almost 13V. I reinstalled it in the Kona, have had no further issues with that older battery. The car sometimes sits unused for 4 to 6 days at a time, no issues with starting now.

 

hi, here some indications related to sulfation and how to prevent it
types of battery sulfation
ther are two types of sulfation in lead acid batteries: reversible( also refered to as soft ) and permanent ( also refered to as hard )
If sulfation is recognised early enough you can sotimes reverse the sulfation of the battery
permanent sulfation build up when a battery has been in a low state of charge for weeks or months . At this stage restoration of the battery or reversal of the sulfation is highly unlikely and as a result the battery will suffer the effect of permanent sulfation.
How to prevent battery sulfation
To prevent sulfation during storage a battery must be keep at a charge of at least 12.4 volts and be stored in an environment where temparature do not exceed 75 degres F ( 24 degres C )
For every 10 degres F increase above this temperature the rate of self- decharging of the battery doubles
Even if youare storing a new fully charged lead acid battery you will need to ensure the voltage does not drop beow 12.4 volts .
Applying a top up charge ( also refered to as a maintenance charge) periodically will help prevent sulfation building up.
Sulfation is the number one raidon you should not store your lead- acid bzttery without charge.