I am designing a circuit which will utilise a lithium ion battery. The circuit would ideally be plugged into a power source the majority of the time, butI would also like it to be portable. I have been doing some research into battery charging and management ICs and circuits. They all seem to be aimed towards charging removable batteries.

How would I go about wiring in a lithium ion battery so that it can be charged and used within the same circuit?

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    \$\begingroup\$ Could you choose one or two datasheets that you feel are representative and edit your question by including links to them? I haven't personally designed such a chip into a circuit, but from skimming datasheets I've been left with the impression that they address exactly your use case. If not, then one might with a bit of help from a microprocessor. \$\endgroup\$
    – TimWescott
    Mar 30, 2023 at 15:07
  • \$\begingroup\$ I believe Texas instruments makes several battery charging ICs that can charge lithium batteries (whether they are permanently wired in or removable). ti.com/power-management/battery-management/charger-ics/… \$\endgroup\$
    – user4574
    Mar 30, 2023 at 15:09
  • \$\begingroup\$ Search for "PMIC", you'll find plenty. Also nearly all dev boards which support use of a battery allow charging it as well, you can look up what IC they use for that. And of course there's the infamous TP4056. \$\endgroup\$
    – jcaron
    Mar 30, 2023 at 15:18
  • \$\begingroup\$ Consider also buying a ready-made power bank: it does what you need, it's reliable, it meets regulations, it's safe, it has a warranty, it's less likely to catch on fire, and it will cost less. \$\endgroup\$ Mar 30, 2023 at 15:29

1 Answer 1


There are battery charger ICs that can handle the case of a load and battery connected.

This is not a specific recommendation for this chip, but one example is the BQ21080. As you can see in the diagram the charger includes a Power Path Controller that automatically allows power to flow from IN to SYS (power source powers load), IN to BAT (power source charges battery), or BAT to SYS (battery powers load). This is the type of configuration that you would want for a permanently connected battery.

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