Most cars use NCA or NMC chemistry which has 500ish cycles. Grid storage will soon use LFP which is cheaper to begin with and has 5000+ cycles. It has a lower density than other chemistries and very poor cold weather performance, making it less ideal for vehicles (though Tesla is using it in the standard range model 3 now). Those downsides don't matter for grid storage and really change the economics of charge/discharge.