Author Topic: Battery reverse polarity  (Read 273 times)

eiscar

  • Newbie
  • *
  • Posts: 2
Battery reverse polarity
« on: February 05, 2019, 08:53:18 AM »
Hi!

I yesterday finally received the LiPo battery I had ordered to power the CurrentRanger. It was late, and in my excitement I just plugged it in. Big mistake. A couple of seconds later smoke started to come from the board (somewhere from the area around the connector). The connector fit was also extremely hard, so it took me a a couple of extra seconds and a cut to my finger to manage to unplug it.  V

Has this happened to anybody before? Any ideas on what elements of the circuit might have gotten fried? Is there hope for a repair?

Thanks a lot for the input!

Best,
Eduardo

alexsh1

  • Jr. Member
  • **
  • Posts: 50
  • Country: gb
Re: Battery reverse polarity
« Reply #1 on: February 07, 2019, 04:39:27 AM »
Hello,

From the CR guide:
Code: [Select]
Double check the polarity of your battery JST connector, proper polarity is marked on the silkscreen, here’s an example of a small 500mAh battery connection:

If a magic smoke has escaped and if you are lucky, the LDO chip (MCP1703) has gone. I would start here and then check the rest of the board. Hopefully, no serious damage.

Felix

  • Administrator
  • Hero Member
  • *****
  • Posts: 5908
  • Country: us
    • LowPowerLab
Re: Battery reverse polarity
« Reply #2 on: February 07, 2019, 12:40:29 PM »
This happened before yes and I will try to prevent it in the next version. It looks like a lot of batteries come in the "wrong" polarity.
I think the damage is going to be in the MCP73831 not the LDO. The chip will be slightly burned or have an indentation or a little dome on it, that's how you know its blown.
You can probably still use it just fine, just you wont be able to charge the battery. The charger (or even LDO if that's the case) can be easily swapped out if you're careful not to lift pads up and melt the plastic connectors around. I can offer a free replacement/repair if you're willing to return the unit to me.

eiscar

  • Newbie
  • *
  • Posts: 2
Re: Battery reverse polarity
« Reply #3 on: February 11, 2019, 11:02:03 AM »
Thanks Felix, that is very generous of you. I am waiting for some connectors to change the battery polarity and will do some testing to asses the damage. None of the ICs seem burned, or show other external signs of damage, so maybe I might be lucky. I will update as soon as I get a chance to do the testing.

Best,
Eduardo

Felix

  • Administrator
  • Hero Member
  • *****
  • Posts: 5908
  • Country: us
    • LowPowerLab
Re: Battery reverse polarity
« Reply #4 on: February 11, 2019, 11:48:59 AM »
Smoke is a bad sign, i bet the charger is burned.