Battery Health Advice

[wuuff]

I realize this may be a stupid question, but I'll try to elaborate why I felt it necessary to ask it.

As has been shown several times on this forum, it is not safe to leave a gamebuino unplugged for several months. If the voltage on the battery gets low enough, the battery will be irreversibly damaged and may never charge again. Therefore, to ensure the longevity of a gamebuino, it is important to semi-regularly charge it to keep the battery charge at a safe level.

However, I feel that there is a non-zero chance that I may forget about my gamebuino in the future for months at a time, due to various distractions. Therefore, I was wondering if there are any negative side effects to simply leaving a gamebuino plugged into a USB charger for long periods of time unattended. Having heard nothing to warn against this, I assume I can trust the charging circuitry to manage the battery level and to never overcharge the battery. It's not like I expect the battery to explode or catch fire; I expect leaving it plugged in is as safe as leaving a cell phone plugged in, but I still wanted to know for sure. Are there any other possible negative effects, such as the charger raising the temperature of the battery and shortening its lifespan?

Thank you for your help with this potentially silly concern.

[Georgian]

It never happened to me anything bad with LiPos but i know that no device using a lipo battery should be left to charge for long periods unattended.
It looks like the battery on the gamebuino dose have a over/under voltage protection circuit (the small PCB on the battery, under the yellow tape), so it shouldn't be a problem if left for month. The battery will drain but nothing bad should happen to the battery. Those batterys dosen't have the "memory effect" like the NiMh ones. Of corse that if the battery goes to a critical level (under 3V i think) it can happen that when you charge it the chemistry inside gets mixed and it can start to swell and in the worst case scenario it can burn (see videos on youtube).
This is my opinion, i'm in no way an expert in batterys, i just use them a lot.

[rodot]

There is a protection included in the battery itself as Georgian said, and the charge management circuit of the Gamebuino will maintain the charge without over-charging your Gamebuino. When the battery is full it stop charging, and when the voltage drop by 10% due to quiescent currents and residual discharge, it tops it up again.
PS : A new revision of the Gamebuino is on the way, changes include a battery connector. This way you can disconnect it when you leave for long period of time, or easily change the battery

[zerosimms]

Guessing this is what we mean by the battery swelling?

https://goo.gl/photos/hLZLpACHxUu7x9Si9

Any idea where I can get a replacement?

[rodot]

You can use any 3.7V LiPo battery of at least 200mAh. You can find them in RC helicopters, phones... or you can buy one one on your favorite electronics website. Just make sure they will fit in the case, or be ready to make a custom case to fit a larger battery The original battery of the Gamebuino is often referred to as "402030" as it's 4x20x30mm.
Few places you can find batteries :
https://www.adafruit.com/categories/574
http://www.ebay.com/sch/i.html?_nkw=Lipo+3.7V+402030

[Georgian]

How did you get that to happen? Make sure you bring it to a recycle center or something. DO NOT POKE IT! I know it's tempting