suggested battery supply for high consumption scenarios

[codifies]

From other posts you can see the bullying I'm giving my poor LiPo > but supposing I wanted to run a 15" LCD and I wanted more than four hours, say I wanted a comfortable 8hrs of reasonable but active use...

Would it be possible to make a circuit to use multiple cells at the same time that could still get a charge from the existing charging circuit? would this be too much for the existing circuit?

would the charging circuit cope with a larger battery that the 6600mha one ?

Does any one know of a charging circuit for a laptop battery that can be interrogated via I2C, GPIO, serial, usb or some other manner by the A20 that would be suitable to power the barrel connector?

charging circuits and batteries are black magic to me, give me binary any day!!!

[dave-at-axon]

It should easily handle a much larger battery if it appears as a single cell to the charging circuit.

The only issue I think you will have is the charging time because of the charging current that can be provided by the AXP device. As I can't find an English version of the datasheet, it is difficult to work out what it can support. There is a setting in the fex file though. On my setup it's set for 1000mA if there is external DC power or 400 if not.

If this is a standalone system you are planning on building and has to run with loss of mains supply, how about a cheap UPS supplying your AC-DC supply? This would give you way more than you are getting now.

[codifies]

http://linux-sunxi.org/images/2/20/AXP202_Datasheet_v1.0_en.pdf

6600mah does seem to take a long time to charge...

What do you think it could handle?

Speed of charge and larger battery ?

Could the setting be tweaked to get the last 20% from the battery with .9A to 1.2A draw? Without causing undue stress to either the SoC or battery?

I'm basically looking for a standalone battery operation similar to a laptop...

See chrisc.bedroomcoders.co.uk to see the set up...

[codifies]

After rereading the data sheet again, the only maximums I can see that are of note is the max charge current of 1800mA which will obviously effect charge time

I'm puzzled by max power dissipation at only 2100mW its not clear if this is charging or discharging or combined.... (you could be charging the battery and powering the board at the same time)

[jess]

On my setup it's set for 1000mA if there is external DC power or 400 if not.

Dave,

Can you show us your [pmu_para] section of your fex file?
I figure that you use 6600mAh LiPo - correct?
In this case you might at least do pmu_battery_cap = 6600
Did you make any other power related changes elsewhere inside your fex file?

[codifies]

I changed pmu_battery_cap to

before
lowest current   0.9480   A
highest current   1.2600   A
bat %age lowest   11   %
total time   04:34   hrs:mins

after
min current   0.922
max current   1.104
Lowest %   11.00%
total time   04:48

not a great deal of difference!

[dave-at-axon]

Dave,

Can you show us your [pmu_para] section of your fex file?
I figure that you use 6600mAh LiPo - correct?
In this case you might at least do pmu_battery_cap = 6600
Did you make any other power related changes elsewhere inside your fex file?

I have indeed set the capacity to 6600. I left the charging and everything else as it is as I don't need a fast charge for my design. I may change the shutdown percentage though but for now I control this from within the application itself.

[jess]

Dave,

Can you show us your [pmu_para] section of your fex file?
I figure that you use 6600mAh LiPo - correct?
In this case you might at least do pmu_battery_cap = 6600
Did you make any other power related changes elsewhere inside your fex file?

I have indeed set the capacity to 6600. I left the charging and everything else as it is as I don't need a fast charge for my design. I may change the shutdown percentage though but for now I control this from within the application itself.

Very similar to what I have here - although I have it set to 8000mAh instead, and left everything else as it is as well.

[N8body]

It should easily handle a much larger battery if it appears as a single cell to the charging circuit.

Can you please explain how to achieve this? Can I connect a bunch of Cells with each 3.7V in parallel to the charger? Or should i have an extra circuit for this?