You can't go wrong with the products the RGP crew offers.
The GBP wireless battery works a treat.
Occasionally I need to remove the battery cover to secure a charge, but I can confirm it's more related to my (POS) Qi charger than the battery. I just flip off the battery lid and it's perfect everytime.
I'm not sure if there's a way to know if the battery is getting low, my GBP doesn't have the battery light in the fascia.