15kWh 48V LFP battery around $1800 with low quality battery management system in metal box on wheels. Car batteries need more expensive inverters if you want to fast charge them (150kW-950kW) and super fast discharge them while driving fast (>100 kW). Thus my 600kW extender comes to almost $62000 for vans and small trucks. Cheaper if installed as house battery. The Mercedes eSprinter 56kW van costs around $80000 new but we sell 3 year old vans like this for $4000 without battery. So refurbished and converted to eCamper with 1800 mile range you pay $6700. You can drive 3000 km (almost 1860 miles) with this battery in the eSprinter and eCamper. A normal size car would go twice as far with this battery but it's big and heavy enough that you need to tow it in a trailer.

The crucial point though is the charging/discharging inverter (converter) that I purpose built (printed circuits boards) and a change to the car firmware. Without it the car will reject the battery, your acceleration would be less and it also would not last the same amount of discharge cycles. My battery electronics works fine for cars, trucks, boats, house and neighborhood batteries (up to 6mW per shipping container).

We build entire smart grids around the batteries, solar panels and tiny houses. https://www.researchgate.net/profile/Merik-Voswinkel/publica...