Wireguard should alleviate exactly that.
It's designed to not use persistent connections, keepalives may have to be enabled in case of nat traversals though (to enable incoming packets).
It's designed to not use persistent connections, keepalives may have to be enabled in case of nat traversals though (to enable incoming packets).
It can leave connection open which prevents many cellular radio technologies from falling into lower power state.
Really depends on how optimized the cell modem is and how often keepalive packets are being sent by the VPN. Honestly, I haven't seen too much of a battery hit on ipsec VPN on the iphone SE. However, my older android phones used to get shredded on OpenVPN.
EDIT: If anyone's asking, I use the algo.sh script to deploy ipsec vpn on digitalocean (has option to enable adblocking too) https://github.com/trailofbits/algo.