you're lucky you're running into models that don't panic in some way without a battery.

for example some alienware and XPS models rely on the battery for amperage capacitance when their big onboard GPUs get busy; allows them to run cooler/less-wattage/smaller wall-warts but it also makes for a platform that'll crash when it hits a high GPU usage without a decent way to make up the amps.

'spose you could use a bigger power supply if you get bios/uefi to play nice. hard proposition sometimes with Dell products.