USB/DC Lithium Polymer battery charger is nice, but I need more voltage

[Florin Andrei]

The USB/DC charger module is exactly what I'm looking for, but I need more than a single LiPo element. In fact, I'll need about 4 elements in series. I need over 12 V for a project, and a way to handle battery charging / discharging automatically and seamlessly. The device needs to switch back and forth automatically between battery and external DC, and I don't want to remove the battery, ever, except when it's too old to stay charged.

How do I do that?

I was thinking to use a laptop battery, but I know nothing about them. Do they have an integrated controller? If so, how do I connect the whole thing?

(I used to design and build all sorts of electronics, up to and including systems with microprocessors, but I stopped 15 years ago, so I know the theory but I might be a bit foggy on details. Feel free to beat me on the head with science, I'll handle it.)

[hjohnson]

Have you taken a look at step-up voltage solutions? It of course depends on how much power you need (you said you need over 12 volts, not what amperage you're running at).

That way, you could have the lipo charger, powered by external DC to power the system and charge the battery, and run the output of that to a boost converter to always get you your 12V. For more information, check out Dave Jones's tutorial on switching regulators here: http://www.youtube.com/watch?v=qGp82xhybs4
--Harry

[fs9]

Have you taken a look at step-up voltage solutions? It of course depends on how much power you need (you said you need over 12 volts, not what amperage you're running at).

That way, you could have the lipo charger, powered by external DC to power the system and charge the battery, and run the output of that to a boost converter to always get you your 12V. For more information, check out Dave Jones's tutorial on switching regulators here: http://www.youtube.com/watch?v=qGp82xhybs4
--Harry

Would it be possible to combine charger/lipo's sets? I have a similar need, only at a little lower voltage, and I came here exactly to ask about it. Having a couple 2.8Ah 3.6v cells giving a total 7.2v while maintaining the amps is just what I need, as I'm building a household monitor that will check on the UPS but should stay on even after power failure and notify me using a GSM interface. Should I expect any kind of issue coming from operating both chargers in sync, like they were two amps of a stereo? Will (sorry, potentially dumb question) the use of both outputs in series affect the lifespan of the lipo cells?
Thanks for the patience, and I won't complain about any literature on this matter anyone should care to throw on me.

[footswitch]

Ok, this topic led me to register in this forum.

Adafruit seems to make their share of solutions from scratch. I'm actually surprised they don't already have this.

I'm looking for the exact same thing.
A standalone accessory that would handle all-things-power: just plug to AC, and output regulated 5V DC, handling up to 3A (4 seconds peak, normal consumption is 300mA @ 5V), with a battery charger featuring automatic switchover and low voltage cutoff to prevent wrecking the battery.

I don't really care about the regulated output. Regulators exist for a reason, and they're the easy part.

For the past 6 months, I've been using a design that I created myself, but:
- needs a 15V 1500mA converter (substantially more expensive than 5V, 6V, 9V or 12V);
- it's heavy (lead acid battery);
- it's ugly and big (because of the reasons above);
- takes time to build (naturally);
- doesn't have low voltage cutoff (so, if power goes out for a whole day, the battery is dead for good).

Adafruit, you could be pioneers in this. Please?

Are there any news regarding this topic, that I'm not aware of?
Thanks in advance for reading.
footswitch

[THENET]

Hi, I have purchased samples of the Adafruit Lithium solar charger PCB's, and need to know who I could contact to develop a similar board with the below characteristics:

1. Charging for 4.2volt 12000mAh lithium Polymer battery pack
2. Using a 6 volt 5 watt panel
3. Also allowing for inwards DC current from both 12 & 24volt VCC
4. The ability for both inward currents to be present at teh same time
5. Outward current supply minimum of 10 volts, maximum of 12 volts (max amp)

I need to develop the system for a project that we are developing for a self powered vehicle solution. I am happy to pay the development costs, and offer MOQ of 500 units

Thanks,

Allen

[THENET]

Sorry for the gramar........... Love spell check.

The outward current ampage needs to be 1amp.

Thanks

Allen

[adafruit_support_bill]

@THENET - You should post this on the Jobs board. There is a section for contract projects.

[adafruit_support_mike]

I'm looking for the exact same thing.
A standalone accessory that would handle all-things-power: just plug to AC, and output regulated 5V DC, handling up to 3A (4 seconds peak, normal consumption is 300mA @ 5V), with a battery charger featuring automatic switchover and low voltage cutoff to prevent wrecking the battery.

The general product category is called a 'power brick', and you can buy them from places like Mouser.

The trouble with creating a general power supply is that everyone wants something different.. 5v, 3v, 3.3v, "a little more than 5v so I can drive a 5v rail with N-mosfets," "I really want split rails so I can use op amps" etc. Current requirements are equally diverse, as are size/shape/portability constraints. The MintyBoost is a solution for one set of constraints, as are LiPos and chargers.