hermanningjaldsson
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Joined: Sun Dec 15, 2019 12:28 pm

AlphaBot, which type of 18650

Sun Dec 15, 2019 12:32 pm

The <a href="https://www.aliexpress.com/item/3300066 ... lphaBot</a> uses batteries 18650.

But does anyone know if it should be the ones with the button top or the flat top?

Heres a button top: https://www.amazon.com/AllForBest-Prote ... 247&sr=8-1

And heres a flat top: https://www.amazon.com/Authentic-Rechar ... 247&sr=8-8

How does one find information like this out? I've been looking through all the AlphaBot catalogues, electric shops, asking electricians, electric store clerks, google, raspberry pi fb chat groups and whatnot and nobody seems to know this.

To put this into a context, I have already wasted $150 purchasing 18650 batteries, only to find out they are not the version of 18650 batteries that are fitting. This time I really want to purchase the correct type of 18650 batteries. The other time I purchased 18650 batteries for the AlphaBot in a vape shop, only to find out that they are slightly too large for the AlphaBot.

Apparently 18650 is not the same as 18650.

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rpdom
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Location: Chelmsford, Essex, UK

Re: AlphaBot, which type of 18650

Sun Dec 15, 2019 1:30 pm

The difference between the batteries is one is an 18650 (18mm across and 65.0mm long) and one is an 18650 with a battery protection circuit added on the end which makes it 18mm across and 69.0mm long.

As the AlphaBot details don't mention using protected batteries, I would assume it takes the standard version ("flat top" as it is called in the listings).

It also doesn't mention anything about a charging circuit, so you may need a separate charge for the batteries.

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Imperf3kt
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Joined: Tue Jun 20, 2017 12:16 am
Location: Australia

Re: AlphaBot, which type of 18650

Sun Dec 15, 2019 8:29 pm

Also beware that many* of the "button top" style 18650s are actually fake or recycled flat top 18650s and are dangerous / should not be used.

*
I have no proof, but I would wager that all of them are recycled or fakes.
55:55:44:44:4C
52:4C:52:42:41

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Gavinmc42
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Re: AlphaBot, which type of 18650

Mon Dec 16, 2019 1:18 am

18650 LiFePO4 are safer but lower capacity and lower voltage.
Button top/flat top, had not heard those terms before.
It explains why some battery holder don't work with flat tops without mods.
It looks like LED torches have been the main driver for these cells.

Hobbyking have universal chargers, I use one of those.
I'm dancing on Rainbows.
Raspberries are not Apples or Oranges

sutan
Posts: 2
Joined: Tue Jan 14, 2020 2:15 am

Re: AlphaBot, which type of 18650

Sat Jan 18, 2020 4:34 pm

Hi Gavin I need to order some batteries, did you find some that worked out for you?

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Gavinmc42
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Joined: Wed Aug 28, 2013 3:31 am

Re: AlphaBot, which type of 18650

Sun Jan 19, 2020 1:44 am

Just last week a I found Li-ion 18650 cells that are protected from over voltage etc.
I think they have a circuit under the top button contact.
A bit expensive here in OZ, but it looks like they are available retail now.
You also need the chargers which are also around now.

Probably as safe as you can get Li-ion until a chemistry change type appears.
A search should find you your local equivalent.

I will be recommending this type now for our use here for gadgets we make and others use.
High current applications like the bigger motor bots won't be good, but small Pi bots should be fine.

I have not got any or checked the specs yet, it's on my list now.
Been busy making a prototype of Pi based 18650 battery rapid charger and discharge testers for student lab use.
I'm dancing on Rainbows.
Raspberries are not Apples or Oranges

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