Using a system while charging it's battery

[chisleu]

I'm having issues finding an off the shelf pcb that can do what I want.

I have a battery powered system that I want to charge without interrupting power like laptops do. I am currently using an over-sized 5vdc buck converter.

Does anyone have any experience with such things? My battery is about 6AH and would prefer at least 1 A of charge current.

[adafruit_support_mike]

Our LiPo chargers do exactly that: http://www.adafruit.com/products/280

Most of the magic lives in the MCP73861 at the heart of the circuit. That does all the level checking, current routing, etc.

[chisleu]

THANKS!

EDIT: It does allow for a switchable charge/run mode, but I'm looking for a laptop style plug in for power + charge circuit.

[adafruit_support_bill]

but I'm looking for a laptop style plug in for power + charge circuit.

Can you be more specific? Are you looking for something with a USB port?

[chisleu]

but I'm looking for a laptop style plug in for power + charge circuit.

Can you be more specific? Are you looking for something with a USB port?

I'm sorry. I mean an uninterrupted power supply and charging circuit.

So I can boot my system and use it on battery, and when the battery runs low I just plug in 1 plug which starts powering the system and then the batteries automatically switch from drain to charge. Much in the way a laptop behaves.

I figured there would be something off the shelf that could do it, given how many cell phones/laptops/etc do it.

[adafruit_support_bill]

All of our chargers do that. You can charge the battery and power a load at the same time.

The SolarLiPo charger ( http://www.adafruit.com/products/390 ) has a more sophisticated load-sharing scheme than the others. It can provide full power to the load while still regulating the charge current to the battery.

[chisleu]

Very nice. Then I am very confused. I'm very happy to purchase 1 solar panel and 1-2 chargers but I don't have room for two solar panels on my little project. I like the word very.

Can I setup these batteries as 2x 2P and connect them to this board: http://www.adafruit.com/products/390 ....
Then put the load sides of the two charger PCBs in series to make my 7.4V for my project?

Here is my project thus far with a temporary / hard wired battery for testing. I still need to add a 3d printed panel with mHDMI and mUSB female connectors and the power input for the charger circuits.

[adafruit_support_bill]

You don't need a solar panel to use the solar charger. It will also accept power from USB or a 5-6V DC power supply.

This guide shows several connection options for multi-cell charging: http://learn.adafruit.com/multi-cell-lipo-charging

[chisleu]

You don't need a solar panel to use the solar charger. It will also accept power from USB or a 5-6V DC power supply.

This guide shows several connection options for multi-cell charging: http://learn.adafruit.com/multi-cell-lipo-charging

Clearly there is something I am missing because I don't see how any of those circuit examples will keep my system from rebooting when you flip the switch. There will be a momentary interruption in power if I understand that correctly. What I'm looking for is a method to plug in a charger cord which will start powering the circuit while charging the batteries. I see that the solar capable charger does that. I would love to add a solar panel to the top of my system, provided I could split it's output to both charger boards. However what I need to know is if this example will work.

Here is a link to the circuit I'm describing: https://docs.google.com/file/d/0BwteEg8 ... RvME0/edit

Could I wire it like so to allow for a single panel slowly charging when possible, and a auto-switching 5v input / charging setup with a 7.4v output voltage for my load?

[adafruit_support_bill]

That circuit won't work. If you want to charge 2 batteries in series, you need 2 chargers. Each of those chargers needs a separate power supply - otherwise they would have a common ground and short out one of the batteries.

[chisleu]

That circuit won't work. If you want to charge 2 batteries in series, you need 2 chargers. Each of those chargers needs a separate power supply - otherwise they would have a common ground and short out one of the batteries.

Since I'm not going to have two power supplies for the device, then I need to find a 7.4v charger instead?

Zut! I was excited about the prospect of using a solar panel.

Thanks for your help.

EDIT:
If I change to use a boost converter, I could use http://www.adafruit.com/products/390 and http://www.adafruit.com/products/500 .

I would have to rig a voltage monitoring / LED scale setup. Maybe there is something I can work out. Again, thanks for your help.