I need to drive a 90w 5v circuit with 18650 batteries

Submitted by Chris on Wed, 06/03/2020 - 06:36

I was wondering if I can do this at all really and I know very little about supplying power with batteries. Would I just use a DC-DC converter like the LTC3780?

Yes, it can be used, but there is a problem. The 18650 has a maximum current rating. You should be careful that the current maximum load current rating should not increase. What is your planing for the input battery spec? voltage? mAH?

  Joined February 12, 2018      696
Monday at 02:11 PM

TP4056 has 1A of current rating. 3 parallel 18650 9900mAH will take approximately 10 hours to charge fully. Is this ok for you? That is a really long time for such applicaiton.

  Joined February 12, 2018      696
Monday at 02:11 PM

Thank you for your reply, I ended up going a different direction and not using 18650 batteries. I used a 7.2v Tenergy NiMh pack and probably wasn't hiting half the max rating of the LED strips as I ran them at 18 brighness instad of 256. I ended up using a 15A rated buck converter just to be on the safe side.

  Joined June 03, 2020      3
Wednesday at 06:26 AM

Good to know this. Use proper protection for the battery charging for a longer battery life.

  Joined February 12, 2018      696
Monday at 02:11 PM