Buteline have available an electric battery-operated mini clamp tool, complete with battery, charger and separate jaws in 15mm, 20mm and 28mm. 

The electric mini tool is small and light -- without jaws fitted, it's only 377mm long and 1.7kg. This lighter weight combined with a short pressing cycle makes the tool very easy to use.
The charge time is now only 15 minutes and the tool can do approximately 150 clamps per charge. The Makita 18V/1.3Ah Li-ion battery can be charged approximately 900 - 1000 times.
For more information, please contact us by freecalling 0800 BUTELINE or contact your local Buteline representative. 

Buteline Electric Mini Tool with Bute Jaws

Electric clamp tools should be serviced every year or at every 20,000 clamps, whichever comes sooner.
For servicing and repairs, please contact one of the below service agents in New Zealand:

Jonel Hydraulics - North Island
7 Blackburn Road, East Tamaki, Auckland, New Zealand 
P: +64 9 274 9296 (ask for George Pavletich)
F: +64 9 274 8231
E: enerpac@jonel.co.nz

Jonel Hydraulics - South Island
29A Epsom Road, Sockburn, Christchurch, New Zealand
P: +64 3 348 9082
E: jason@jonel.co.nz

Service agents are also available in Australia and the United Kingdom.