olimexino-nano with lipo-charger and 3.7v li-ion bat

[gauteh]

Hi,

I'm planning to power an Olimexino-Nano with a 3.7 li-ion battery similar to https://www.olimex.com/Products/Power/BATTERY-LIPO1400mAh/. With the https://www.sparkfun.com/products/10217 charger in between.. Can the Nano handle 3.7 V on the 3.3 input terminal? There are some VBAT1 and VBAT2 terminals as well, should I rather use those?

Cheers

[LubOlimex]

No. Consider that the charger provides more than 4.2V. Consider also that a fully charged Li-Po battery provides typically more than 4.2V.

[gauteh]

Thanks, I assume the olimexino-nano-bat shield downscales the voltage correctly. According to the Atmel ATMega 32U4 datasheet it has an operating range from 2.7 to 5.5 V. Is the limit caused by other components on the Olimexino-nano board?

Also; I tried to power the Nano with a coin cell battery (3V, lithium) using the nano-bat module - this seemed to make everything go much slower. I also powered a repaper e-ink display through the same battery so that was probably the reason, even with powering off (0) the nano (and e-ink display) between renders the battery drained in no time. The size of the coin cell battery is not specified for the nano-bat module, 2430 seemed to fit, is this the correct battery?

• https://github.com/rocketscream/Low-Power/blob/master/LowPower.h#L147

[LubOlimex]

Just use the VBAT2 pin (CON1 pin #6) of OLIMEXINO-NANO for the Li-Po, it should be alright. Make sure not to use the 3.3V or VBAT1 pins (the 3.3V pins require exactly 3.3V; the VBAT1 pins are for the coin battery 3.0V).

The coin battery should be CR2032. However, I wouldn't count too much on the coin battery - there are too many counterfeit ones and sometimes these batteries spend a lot of time on the shelf in the store. My experience with coin batteries had been awful most of the time. A Li-Po battery is the better option.

[gauteh]

Thanks, that's very useful.