There are quite a few projects I have planned that will be powered by various combinations of Li-PO or Li-ION batteries. In all cases I'm going to need to quickly check the remaining charge, and provide an obvious notification if I'm in danger of reaching the over-discharge point. I've thought about many simple circuits to do this and I'm open to others. But so often I've re-invented wheels where a cheap and "already done" solution exists. Can anyone point me to some ready made solutions? The ideal would be something where I could simply "dial in" or "set" some voltage points I want to watch for, with maybe a few LEDs to indicate battery health when a button is pushed, and maybe a steady (or better yet blinking) warning LED when, for example, a 3s Li-ION pack got down around 9V.
Like I said, i can think of some simple circuit designs, probably with an LM3914, but I'm hoping for minimum parts, or many just "1 part" if what i want already exists in a cheap ready made module or IC.
Like I said, i can think of some simple circuit designs, probably with an LM3914, but I'm hoping for minimum parts, or many just "1 part" if what i want already exists in a cheap ready made module or IC.
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Start here. Ya might find something to fit yer needs..
Shop lipo charger module online Gallery - Buy lipo charger module for unbeatable low prices on AliExpress.com
Shop lipo charger module online Gallery - Buy lipo charger module for unbeatable low prices on AliExpress.com
Have you seen TI's products?
Battery Monitor, Protection & Authentication Solutions IC | Products | Power Management | TI.com
I'm OK on the chargers, having found plenty of cheap fully fabricated ones, and in most important cases I buy Li_ION cells with built in protection anyway. The current project that comes to mind is a portable guitar amplifier, where the main issue is being able to keep reasonable track of how much "playing" time you likely have left. So for that, a few LEDs to give an indication will be fine.
Honestly, I'm probably being lazy... I doubt I'll find something simpler chip than an LM3914 and a few LEDs (I don't have to use all 10). I'm just weary of having to fabricate every last thing.
I'm just weary of having to fabricate every last thing.
Here are some that may work, for a few dollars each.
Shop lithium battery indicator online Gallery - Buy lithium battery indicator for unbeatable low prices on AliExpress.com
Yeah thanks again! I think I found a winner among those listed on your ali-express link. This forum still doesn't allow photo uploads, but its the one with 4 T-1 LEDS and all SMT parts. Comes to just a couple of dollars, worth it to me to have a "snap in" test (one less thing to do!!!!).Its actually a few cents cheaper then just a single LM3914 in its surface mount version.
The one I'm describing is only for one cell, and I was looking for 2 and 3 cell circuits. But it occurs to me that just measuring one cell is probably good enough. Really, measuring the total of multiple cell voltages would be no better guarantee of inaccuracy due to severe imbalance. I'll likely have to power it with a "push to test" switch to make it practical.
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