This is a placeholder topic for “Adafruit LC709203F LiPoly / LiIon Fuel Gauge and Battery Monitor - STEMMA JST PH & QT / Qwiic” comments.
Low cost Lithium Polymer batteries have revolutionized electronics - they’re thin, they’re light, they can be regulated down to 3.3V and they’re easy to charge. On your phone, there’s a little image of a battery cell that tells you the percentage of charge - so you know when you absolutely need to plug it in and when you can stay untethered
Read moreWondering what is the difference between this, and “Adafruit MAX17048 LiPoly / LiIon Fuel Gauge and Battery Monitor - STEMMA JST PH & QT / Qwiic” ( SKU: ADA5580) ?
I assume they use different ICs, but both appear to do the same thing, and it looks as though the description was a copy and paste job. I have just come across a blog post which suggests MAX17048 is much more accurate than INA219.
As a customer I really want to know which is better (depending of course on my different purpose).
I recently bought a “DFRobot Digital Wattmeter” (SKU: SEN0291), and just now found that DFRobot sell a MAX17048-based “Gravity: I2C 3.7V Li Battery Fuel Gauge” (SKU: DFR0563) … and of course checking which of the other brands you sell have essentially identical products (and the difference in prices).
Hi Donald,
For most makers there might not be too big of a difference, getting the SoC is a huge level up for a lot of projects.
From what I interpreted from the datasheets:
Accuracy
Available outputs
I guess now its a choice of price vs features, do you need the increased accuracy or current sense capability?
LiPo cells ought to have a much more accurate SoC reading from just the voltage, over a flatter voltage curve chemistry like LiFePO4.
Keen to hear your thoughts!
Probably the wrong thing to say to me 
I come from a software background so am trying to pick things up as I go. The various types of battery are a learning curve (mountain) still in my future 
I agree that having any battery monitoring is a huge level up - but why stop there ? We know that Lithium batteries and solar panels put out variable amounts of power - that’s why we need specialised boards to manage them. Why is it not reasonable that we want to track the power levels ?
Given the MAX17048’s apparent higher accuracy and more detailed info, and the low cost of this Adafruit version, there is no choice I suppose really its a case of “voltage = 3.27v” wouldn’t have the same urgency as “battery 12%” ! In my case the bigger consideration (which I keep on forgetting) is whether the device is supported by my software ecosystem (I have gone the RasPi and ESPHome route, whereas most of the support is for Arduino 
) and physical connections.
It is a pity that Core’s website’s “Related Products” tab shows unrelated products which supposedly other customers looked at or bought - instead of the similar products from the other suppliers which you sell.
I can understand skipping battery monitoring in low cost products; or in a UPS intended to cover a max 30 minute mains power outage. But even in a UPS, don’t you want to know how much the battery performance has degraded over time, and when it’s time to replace the battery ?
I can’t imagine why DFRobot provides no monitoring capability whatsoever in their top shelf Sunflower: Solar Power Manager boards (which they describe as “for IoT or off-grid projects”). I would expect that from budget products, or an electrical supply company … but from a business built around intelligent controllers, and with real-world applications in mind ?
DFRobot are certainly not alone in this - but it was the diagram for their Solar Power Manager on their I2C Digital Wattmeter (SEN0291) page which suggested for me the importance of monitoring battery and solar inputs by adding 4 Wattmeters effectively doubling the cost. Personally I think monitoring the solar panel and battery inputs are particularly useful, and of course building them into the main board should reduce cost further. It seems odd that even with this top shelf unit we are expected to add battery monitors and presumably buck/boost on the outputs before connecting to our microcontroller.
Have a great day !
Cheers, Don
Hi @Donald23173,
What a deep dive we have here.
It’s kind of for the reason you listed above, lots of hobbyists will skip the monitoring or spec their projects appropriately to ignore it, when there are these external solutions available they can be added down the line.
In all my projects I have battery monitoring in one way or another. Usually, I just care about the charge and don’t care so much about everything else. A voltage divider works here.
Glad to have you here Donald!
Trust me, batteries go very very deep - like most topics.
A quick electronics definition: Power = voltage x current
Whereas with a battery the main variable we want to track as makers is charge (how much juice we have left), charge = remaining chemical potential inside the battery, usually related to the voltage across the terminals for LiPos.
The two options you originally were asking about monitor charge, not so much power.
Looking through the ESPHome integrations there is one for this: Analog Devices MAX17043 battery fuel gauge — ESPHome
Gravity: I2C 3.7V Li Battery Fuel Gauge | Buy in Australia | DFR0563 | DFRobot | Core Electronics
Strongly agree, having the percentage there is invaluable, thankfully, with LiPo’s its pretty easy to map the voltage to a SoC (state of charge) in percent, depending on how far down the curve will depend on how you map the voltage.
(However note that this is the open circuit voltage)
I imagine this is an artifact of how the backend works, for much more considered groupings, take a look at the categories: Battery Monitoring - Power & Batteries Australia
The cell health is a bit more difficult to decode from the device its powering, and a lot of things affect how fast a cell ages - there are some great resources around the net and I simply wont do the topic justice.
To be honest, me either! It makes sense that they make another version with those monitors added, but I guess they do also produce them sooo…
In that example they are measuring the consumption of absolutely everything, so pretty overkill but at least one for the battery would have been a great addition.
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