7V battery - specific size?

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Mraz
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7V battery - specific size?

Hi. I’m working on something and I need a 7V battery with at least 2Ah and I’m limited to max dimensions of 30×30×58mm. Anyone have an idea what could work?

Only thing I found so far is something like that: https://www.aliexpress.com/item/32799575724.html

In theory, I could fit two and connect in serie to get 7V (7.4V), am I right? But how does one charge them then?
alpg88
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3.7 is nominal voltage, fully charged they are 4.2v by the time they are drained to 3.7v they will have about 40% charge .

get 2 18500, wire them in parallel, install a dc dc boost circuit, set it to 7v, and charge them with usb charger circuit, there are tons of either circuits on ebay.

Sirstinky
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You could do those and wire in a boost converter set to 7 volts really easily. Something like this: Boost Converter $0.50 9%OFF | TZT MT3608 DC-DC Step Up Converter Booster Power Supply Module Boost Step-up Board MAX output 28V 2A for arduino I’ve been using these for years and they’re great. Remember that your output is limited by the input, so be aware these are limited to 2 A output.

Mraz
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Stupid me, didn’t think of a boost converter.

Can you recommend me a specific one? The link above doesn’t work.

Sirstinky
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Sorry the link doesn’t work. Here’s a good one I’ve used (good to max 2 A though) Boost converter

If you need more power, a little better efficiency, this one: XL6009 this is good to 4 A.

Depending on what you’re running, if it’s an led, you need. CC/CV module to set the current limit like this: CC/CV I’ve used that one before and it’s pretty good for under 6A maximum

alpg88
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what current are you pulling from the converter?? it will be at least 2x as much on the input side, make sure your cells can handle it. and you most likely will have to attach the converter to a heatsink,