Why Did DeWalt Discontinue 18V Batteries?

There is a DeWalt power tool for basically any home or work site need, but you may have noticed that none of them have 18V ...
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10 Best Replacement Battery For Dewalt Xrps | Tools & home improvement | Recombu

Voltage: 14.4V/Capacity: 3600mAh/Type: Ni-Mh/Package Include: 2*DC9091 Battery Compatible with Dewalt 14.4v xrp battery dc9091 dw9094 dw9091 ddc9094 de9091 de9092 de9038 dw935 dc984 dw954 Compatible ...