Battery 900mAh and charger

Hi guys.

Can anyone tell me if I can use this battery and charger module with spark core?
Thank you.

Datasheet for those interested:

@SalomaoJr: I don’t see why not. Your main problem is that 3.7 volts is just too high for direct connection to 3.3v. The onboard regulator can handle between 3.6v to 6v you’ll need to plug directly into the VIN and GND of the Spark Core

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Ok, thank you.

@SalomaoJr, just be aware of this:

Make sure the LiPo has a protection circuit on it so the voltage does not drop below the “danger” level. From the looks of yours, it should be ok. :smile:


Of course you can use this battery. But the full capacity of the battery cannot be used because the input regulator of the core can only handle a minimum of 3.6 Volt. The cell itselfs can go down to at least 3.0 Volt. A fully charged LiPo battery has a voltage of 4.2 Volts. So I think you can use 50% of the capacity with this configuration.

In your case, you will likely not have the same problem I had with my weather station. I use a 4-cell NiCd battery where one cell drops suddenly. The remaining 3 cells run the core quite well. During this winter time the sun was shone very rarely and the battery was not loaded enough during the day time. I use a power converter which delivers 3.,3V from 2.3V up to 8V. For a converter, lower voltages mean higher current. The batterys deliver lower currents as the voltage drops down. So there is the problem, my battery drops completely because of lack of power, then the converter turns off and the battery suffered and the converter starts to power the core again.

For your application, take a power converter which operates from 3V to 4.2V. If you could implement a battery voltage measurement, you are able to protect the battery from deep discharge just by software.

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Hi @digixx I’m interesting in powering my Core this kind of battery too just a higher amp than that. However, in your post you stated that OP needs a power converter. My question therefore is why would you need a power converter? Why cant you just power the Core from the 3.7V battery since the spark can run fine with 3.7V?

Hi, suckms

I use 4 cells NiCd.

When you use a single Lipo cell, the voltage range goes from 4.2V for a fully charged cell, to about 3.0V for a discharged cell.
The voltage regulator on the core needs at least 3.6V to supply 3.3V to the core.

Lets see what happens when you run a Spark core directly on a single Lipo cell fully loaded to 4.2V

Lipo voltage higher then 3.6V => the core runs as expected
Lipo voltage comes close to 3.6V (half capacity left) => the core runs as expected
Lipo voltage drops under the safe input voltage => who knows what the core does. The regulator cannot supply the needed 3.3V. Brown out conditions may happen.

If you use a voltage converter which give direct stable 3.3V from an input range of 2.5V to 8V, you can be sure that the battery can go down to 3V and the core is still powered with a voltage of 3.3V. Of course, you must monitor the Lipo voltage to ensure to cut the power when the Lipo is on the lowest voltage possible before it damage the battery.

Using a up/down power converter, I can avoid the loss of the 0.3V from the onboard linear power regulator. Monitoring the battery voltage is essential in this case.