I have replaced std batteries in both my locators with Li Ion batteries from a company called Shorai. They make several sizes and capacities of 12 volt batteries. It’s been three years now and I have been completely satisfied. No special charger needed and my locators feel feather light compared to using lead batteries. Also, I have never run out of power, although I usually charge every day or two. The battery power indicator on one of the units (Vex) never seems to drop below 100%.

The bad news is they are expensive. Also if you talk to someone at Shorai,they will tell you their batteries are not intended/designed for slow draw usage. But I have never had a problem of any kind. Hope that helps.