On Mar 1, 7:44=A0am, Bob <b...@mailinator.com> wrote:
> On Feb 29, 5:23 pm, Paul Stewart <paulstew...@phawfaux.co.uk> wrote:
>
> > I have been googling on an off but not managed to find anything
> > suitable. =A0I wonder if anyone on here is able to help.
>
> > I have a home made laptop. =A0My problem is powering it from battery. =
=A0I
> > am looking for a battery pack that outputs 12 and 4/5 amps. =A0However 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?
>
> You need to consider;
>
> How well regulated do you need the 12volt supply to be?
> How long do you want to run from batteries?
> How important is weight?
>
> Battery packs vary somewhat if voltage between fully charged
> and nearly exhausted. For example can your equipment
> cope with say 11volts to 14volts?
>
> If you need a maximum variation of say 11.5V to 12.5V you are going
> to need a regulator or switcher between the batterys and the
> equipment. That gives you the option of using a different battery
> voltage, eg use an 18volt or 24volt battery pack with
> a 12volt output DC-DC converter module.
> There are plenty of off the shelf modules eg a Traco Power
> TEN60-2412
>
> I'd look at either gel-cell or AGM lead acid batterys or a stack of
> 18650 lithium ion cells.
> Either way, theres a lot of current available and you need to
> include fuses and suitable insulation.
>
> People generally seem to make homemake laptops
> by putting an LCD screen, a motherboard and a keyboard
> in a robust metal suitscase. A series stack of 6volt
> alarm batterys would probably fit in reasonbly well.
>
> Lead acid will be heavier. Lithium ion will be more expensive.
>
> A lead acid float charger will supply power for other things
> as well as charging the batterys. Plenty of cheap
> chargers on ebay direct from Hong Kong. A float
> charger will hold the battery voltage at 13.8volts.
>
> A constant voltage current-limited lithium ion charger would
> probably work ok as well though drawing current might
> interfere with the fully-charged detection. You can probably
> find somthing suitable with a bit of searching.
>
> 12V times 4A =3D48watts, twice the power used by many laptops.
> Four 6volt 10AH lead acid batterys and a 90% efficiency
> DCDC converter dropping 24V to 12 volt would give you
> around four hours on batterys.
>
> Bob
Are you interested in APP SB Power Pole Connectors.
AMP 50 Connector.
SB 50 amp connector (gray, red, black). 50 amps maximum, for #6 gauge
stranded wire. Housing and 2 contacts supplied. 1-7/8" overall length.
Available in Gray, Red, and Black. Gray will be provided if no
preference is given. Each color will mate ONLY with the same color.
Also available for #10/12 AWG wire. 50 Amp Power Pole Connectors:1
Housing+2 Contacts one color mates with the same color only. It is: 50
amp rating, 600 Volts continuous AC or DC operation. UL listed.Made in
China,manufacturer of Ningbo Electric Pneumatic.
http://www.ningbo-electric.com/power-po ... -Power-Co=nnectors.html