U3V70A for charging supercapacitors

Im just looking to use a U3V70A to charge a string of supercapacitors to 16V from a 12V supply
There are 6 x 2.7V supercapacitors in series to make 16.2V .I would like to charge them to 16V
Looking at the specs of the specs of the step up voltage regulator I think it will be OK .
Am I missing anything

I suspect the in-rush current from your super capacitors would trigger the short-circuit protection of the U3V70A and it would not be able to start up. Our U3V50AHV regulator does not have short circuit protection and does have cycle-by-cycle over-current protection, so it might be more appropriate. Unfortunately, we have not tried charging super capacitors with either regulator, so I cannot say for sure.


Thanks Claire
As I already had the U3V70FA sitting here and was curious .I tried it yesterday
It starts and appears to work well ,getting marginally hot but its working ( I will put heat sink on and keep trying)
Thanks for your reply it is appreciated

Unfortunately it didn’t go well .Not sure what happened here
Was working well till it failed

Wow, that is some spectacular damage! It sounds like it worked for some time before failing; do you know when it failed (e.g. right after power-up when it started charging the super caps)?


Hi Brandon
I am using the Supercapcitors as a starting aid on a motorcycle .It worked well charging them possibly 30 charging cycles .It was warm but not too hot .I put a heat shrink sleeve over it so it could not short on anything .I did not shrink the sleeve ,just used as a protection .
All of a sudden it just failed the charge input ( earth ) wire has also melted ,then it shrunk the heatshrink onto the board and caught fire !!!

Since it seemed to work for many cycles and the regulator was powered from the 12V battery on your motorcycle, it seems more likely to me that some spikes from the engine got to too high a voltage and damaged the regulator IC causing a short to ground. You might find this application note about suppressing transients in the automotive environment interesting.


Update on this project
I have changed to this board as suggested
When charging the Supercapacitors from 8V to 16V from a 12 volt source .The board is getting to approx 60 Degrees C at the arrows .What are your thoughts


It is not unusual for that diode to be one of the hottest components on the board, and in general 60 degrees C is not very hot for electronics. Did you see some issue that prompted you to look at the temperature of the regulator?


As I had the melt down of the other board I just wanted to make sure .Thanks