There is another Brand just release to the marketplace. The Greenworks
They have two Battery Power models 60V.
Click to see the Greenworks details Description & Specification
Like any other trimmers, regardless of trimmer's brand and models, Gas or Battery Power. They all have an issue.
Too hard to control and maneuver, as the trimmer rides on the back two wheels.
The worst thing is, you have to push down the trimmer handlebar, to raise the trimmer-mow-ball above the ground.
The trimmer is heavy, the engine vibration, uneven ground and rough terrain, potholes.
Users constantly fighting to control and balance the trimmer during trimming.
It is hard to trim for a long period, as users getting tired and felt pains in their body.
Below is the Description & Specification of the Dr Trimmer models.

Model - DR  PULSE 62V - Self Propelled
Motor: 850W Brushless
Cutting Wide: 18 inches
Cutting Height: from  2" - 4"Wheel Size
14” x 1.75” width
Frame: 14 Gauge Steel
Battery: 62V 5AH lithium-ion
Dimension: 35 in x 22.25 in x 24 in
Weight: 40 lbs. - 45 with Battery
Accessories: Tree Guard, Belt and String
Torque: 7.6 lbs. ft.
Charge time: 90 minutes
Run Time: 40 minutes
Body Frame Deck: 14 gauges Steel
Type: Self Propelled
Warranty: 2 years

Model - DR  PULSE 62V - Manual Push
Motor: 850W Brushless
Cutting Wide: 18 inches
Cutting Height: from  2" - 4"Wheel Size
14” x 1.75” width
Frame: 14 Gauge Steel
Battery: 62V 5AH lithium-ion
Dimension: 35 in x 22.25 in x 24 in
Weight: 40 lbs. - 45 with Battery
Accessories: Tree Guard, Belt and String
Torque: 7.6 lbs. ft.
Charge time: 90 minutes
Run Time: 40 minutes
Body Frame Deck: 14 gauges Steel
Type: Manual Push
Warranty: 2 years

Model - DR  Pilot
Engine:  OHV 170 CC
Cutting Wide:  22 inches
Cutting Height:  from  1 1/2" - 3 1/2"
Wheel Size:  14” x 1.75” width
Frame:  14 Gauge Steel
Drive Belt:  V-Belt, 3L440
Dimension: 35 in x 22.25 in x 24 in
Weight:  55 lbs.
Accessories:  Tree Guard, Belt and String
Torque:  7.6 lbs. ft.
Oil capacity 16.9 oz. - 30W
Gas capacity:  1.6 qtrs.
Starter: Coil Start
Type: Manual Push
Warranty:  2 years

Model - DR  Premier
Engine:  OHV 170 CC
Cutting Wide:  22 inches
Cutting Height:  from  1 1/2" - 3 1/2"
Wheel Size:  14” x 1.75” width
Frame:  14 Gauge Steel
Drive Belt:  V-Belt, 3L440
Dimension: 35 in x 22.25 in x 24 in
Weight:  57 lbs.
Accessories:  Tree Guard, Belt and String
Torque:  7.6 lbs. ft.
Oil capacity 16.9 oz. - 30W
Gas capacity:  1.6 qtrs.
Starter: Coil Start
Type: Manual Push
Warranty:  2 years

Model - DR  PRO
Engine:  OHV 185 CC
Cutting Wide:  22 inches
Cutting Height:  from  1 1/2" - 3 1/2"
Wheel Size:  14” x 1.75” width
Frame:  14 Gauge Steel
Drive Belt:  V-Belt, 3L440
Dimension: 35 in x 22.25 in x 24 in
Weight:  62 lbs.
Accessories:  Tree Guard, Belt and String
Torque:  9.7 lbs. ft.
Oil capacity 16.9 oz. - 30W
Gas capacity:  1.6 qtrs.
Starter: Coil Start
Type: Manual Push
Warranty:  2 years

Model - DR  PRO XL
Engine:  OHV 201 CC
Cutting Wide:  22 inches
Cutting Height:  from  1 1/2" - 3 1/2"
Wheel Size:  16” x 1.75” width
Frame:  14 Gauge Steel
Drive Belt:  V-Belt, 3L440
Dimension: 35 in x 22.25 in x 24 in
Weight:  71 lbs.
Accessories:  Tree Guard, Belt and String
Torque:  10.3 lbs. ft.
Oil capacity 16.9 oz. - 30W
Gas capacity:  1.6 qtrs.
Starter: Electric Start
Type: Manual Push
Warranty:  2 years

Model - DR  PRO XLSP Self-Propelled
Engine:  OHV 201 CC
Cutting Wide:  22 inches
Cutting Height:  from  1 1/2" - 3 1/2"
Wheel Size:  16” x 1.75” width
Frame:  14 Gauge Steel
Drive Belt:  V-Belt, 3L440
Dimension: 35 in x 22.25 in x 24 in
Weight:  83 lbs.
Accessories:  Tree Guard, Belt and String
Torque:  10.3 lbs. ft.
Oil capacity 16.9 oz. - 30W
Gas capacity:  1.6 qtrs.
Starter: Electric Start
Type: Manual Push
Warranty:  2 years