Hi all,
Need a controller chip suitable/configurable for 3.7V cells. Any suggestions?
thanks.
Hi all,
Need a controller chip suitable/configurable for 3.7V cells. Any suggestions?
thanks.
What capacity? What charge current?
MCP73831, SOT23-5, programmable charge current up to 500 mA, thermally limited.
Sixty seven cents ($0.67). Needs 2 caps and a resistor. Optional LED + resistor to show charging
Sorry! Yes, 1090mAh; charging at around 500mA would be fine.
Sounds good - on the face of it, anyway.
Actually IIRC that chip outputs too much for a 3.7V cell. :(
Are you designing a product or just need a good LiIon battery charger?
If the latter, I suggest a fairly universal "balance charger" as used in radio control hobby devices. I have an iMax B6: More:
Or, if you want to keep it simple for one cell:
However, if you're designing a product around the chip, I'll pass due to lack of experience.
-- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
nope, they're designed for 3.7 volt LiPo cells -- we use large numbers of them.
The latter. But these aren't regular cells, they have problematic connectors so there's no off-the-shelf solution. That's why I'm building one from scratch.
Thanks! I'll go with that, then.
Could you be a bit more specific? By not being a regular cell (whatever that means), are you dealing with exotic chemistries or internal protection circuitry that's getting in the way?
For simple cells, I've built custom charging fixtures using spring pins and clips for the battery contacts. For the charger section, I just butcher an external cell phone battery wall charger or use a programmable charger PCB to deal with different charge currents.
I haven't tried this, but it looks like it could do most anything you want:
-- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
No it's entirely standard. The problem is the way it's encapsulated, that's all.
Well, ok. Methinks that starting with a charger chip and building a suitable charger might be a bit overkill for what seems like only a connector problem.
Incidentally, flat LiIon cells will bulge when charged. That means the case has to have some room inside for expansion. To me, "encapsulated" means potted, which won't work with LiIon because of this expansion.
-- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
Heh heh heh. The Battery of the Bulge?
Not a problem, Jeff. I'll be using the original charger case designed specifically for this cell and its encapsulation. I'm simply replacing the control circuitry, that's all.
Nice. I like that. My contributions:
- Inflated claims and specifications.
- Bursting with power.
- Bubble packaging.
- Charged with a fault and battery.
- Built in case opener.
- Puff the Magic Ion.
- The mini big bang.
- I'll huff, and I'll puff, and I'll blow the case up.
- Magic smoke inside.
- Poof. Game over.
- That's swell.
My favorite bulging batteries are the older MacBooks, which have the battery mounted directly below the trackpad. When someone calls with a "trackpad doesn't work" problem, I'm fairly certain that the battery has bulged and will need replacement.
Drivel: In a past life, a small part of my job was to create such advertising slogans. However, mine were not intended to be the real slogan because that was already pre-selected by upper mismanagement. My slogans were to be as awful as possible, so that by comparison, the pre-selected slogan would seem to be far superior. It worked. I've often suspected that the new Keysight Technologies name was selected in much the same manner: Altogon Technologies Altagon Technologies Vectelo Technologies Sightshift Tech Stormkey BoldSight Keyhawk Boldfire Yeah, I guess Keysight Tech was the least evil.
-- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
Hi Cursitor,
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Regards Leo snipped-for-privacy@setfuse.com
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