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PiGrrl LiPo battery experience?
Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.

PiGrrl LiPo battery experience?

by WickedWind on Mon Aug 12, 2019 4:54 pm

Hello again,

Thanks to the help of the forum (and support staff in particular) here I've finally managed to finish my PiGrrl:
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Thank you so much, for starters - my train trips will be much better for it.

Having done some reading about Lithium Polymer batteries being somewhat...explosive under duress, I was hoping to hear from anyone else who's built one of these: Did the battery placement between the Pi and TFT cause you any concern or worse yet, actual issues, due to heat or damage from proximity to pointy components?

I understand that the battery itself has protection built in, and that the Powerboost 1000c will limit charging rates etc - I'm mostly just reaching out to get opinions from a similar context, as the general chatter online seems to range between 'quite safe' and 'pocket Chernobyl'.

Thank you

WickedWind
 
Posts: 13
Joined: Sat May 04, 2019 10:58 pm

Re: PiGrrl LiPo battery experience?

by adafruit_support_mike on Tue Aug 13, 2019 4:17 am

LiPos are normally in the 'quite safe' region. There are billions of them in cell phones which people carry near their body and hold next to their head every day.

LiPos go into the 'explosive' range when you mistreat them, either by physical damage or making them discharge too quickly.

Heat doesn't move LiPos out of the 'quite safe' region until you get above 70C or so.

A flat LiPo pack should be retiredm immediately if the foil pouch is punctured or bent. Small dents along the edges of the pack (less than 1mm deep) are usually okay because they don't put unnecessary pressure on the positive and negative plates inside the LiPo.

The PiGrrl construction is designed to avoid any any operating conditions that would move the LiPo out of 'quite safe' territory.

In general, LiPos are okay if you treat them with reasonable care and don't try to modify them. The most common "don't do that" is when people want to put multiple LiPos in parallel to make a battery with more storage capacity. That's a bad idea because every LiPo sees every other LiPo as a short circuit. The only way to keep them from trying to pump excessive current through each other is to have their voltages match to within a few millivolts, and you can't do that with randomly-selected LiPos.

adafruit_support_mike
 
Posts: 59131
Joined: Thu Feb 11, 2010 2:51 pm

Re: PiGrrl LiPo battery experience?

by WickedWind on Tue Aug 13, 2019 5:42 am

Thanks for your input Mike, very much puts my mind at ease and much appreciated.

I don't think I managed to dent or bend the battery during install so not too stressed about it. Great to hear it was considered as a part of the PiGrrl design though, refreshing to hear when people care about safety nowadays :)

To be honest, even if the thing did hand grenade on me...I'd just build another one but better with flames of irony painted on it.

I'll take a few precautions like ensuring it's transported in a container that can absorb any potential shocks or drops etc and only charge it when I'm around, but other than that I'll just enjoy the thing.

Cheers

WickedWind
 
Posts: 13
Joined: Sat May 04, 2019 10:58 pm

Please be positive and constructive with your questions and comments.