12v 4amp rechargable battery

I have been googling on an off but not managed to find anything
suitable. I wonder if anyone on here is able to help.

I have a home made laptop. My problem is powering it from battery. I
am looking for a battery pack that outputs 12 and 4/5 amps. However I
also want something that comes with a charger and that will provide
enough current to both keep the battery charged and power the unit
when plugged into the mains.

Anyone any ideas on how I can achieve this?
.

Relevant Pages

  • Re: Freezer Current Safety Indicator?
    ... that you could connect to a battery and a buzzer... ... Parallel Voltage measurement. ... The mains failure might be a circuit beaker or mains power as you suggested. ...
    (sci.electronics.design)
  • Re: UPS batteries
    ... recharging the battery from the AC line. ... less -- is properly called a Standby Power Supply. ... "THE INVERTERS IN some UPS's actually power the load continuously ... a switch disconnects the load from the AC mains ...
    (sci.electronics.repair)
  • Re: Advice in mini-ITX
    ... For power I use a picoPSU at 60W. ... input I can build a battery backed PSU rather than a UPS. ... without conversion back to mains. ... chargers can switch back to bulk charge from trickle mode without being ...
    (uk.comp.os.linux)
  • Re: Inspiron 6000 LCD - Backlight issue?
    ... rebooting on battery only with mains disconnected. ... if it involves different power wires going into the inverter and the ... brightness is that the laptop senses the power source and allows ...
    (comp.sys.laptops)
  • Re: Things we remember...
    ... source independent of the mains? ... Where does their power come from? ... they may well have emergency generators. ... One of the signals on phone lines is called "battery" for a reason... ...
    (rec.arts.sf.written)