I'm trying to expand capacity for a Duracell power bank (3.7v 2600 mAh) so I can power my portable RasPi project with it. I've taken a battery (3.7v 2800 mAH) from a cheap tablet and I'm wondering if I just connect the negative of the Duracell to the positive of the Tablet battery then take the negative of the Tablet battery and connect it back to the board of the Duracell power bank, if it will increase the capacity of the power bank and function normally or will it blow up in my face melting it Raiders of Lost Ark style?I'm a novice hobbyist and any pointers would be a huge help.A little more detail about my project: I'm installing a RasPi with RetroPie into an Original Gameboy case for a pretty cool emulator. I've found a step up chip to power the new display but have run into the issue of portable power. I'd like a little more capacity than the batteries that I've seen Ben Heck and others use. Thanks for your time and I hope to hear from anyone
Hi Jack, I am not sure that this is a good idea as they are two different types of batteries and may not be compatible. Especially when you go to recharge them. You mention hooking them up in series, plus of one battery to the negative of the other. This will double your voltage to 7.4 volts but will not give you more capacity only more voltage. For more capacity the batteries would have to be hooked in parallel or plus to plus and minus to minus. There are guys on the site that know a lot more about these types of batteries that I do. I would recommend holding off until one of them looks your situation over.
The tablet cell appears to have protection, while the other is a high discharge version.
You are very likely to have different discharge rates, meaning one will go flat before the other, and with no battery management, you're likely to destroy it.
Charging is another issue.
LiPo batteries are known for catching fire when incorrectly charged, so you will need to do something.
Do yourself a favour and buy something that suits what you need, or are at least the same.
Mark
BTW its not your face (although the toxic fumes may be an issue) it's the house you should be worried about.
One of the few ways to put out a LiPo fire is smother it with sand.
