I need a high temperature LiPo battery for a project I am working on. The device will be deployed in high temperature areas (140 - 150 F) and needs a LiPo battery as power is not stable in the area. Most LiPo on the market only charge to 45C, I need one that will charge @ 70-80C. I have found a few suppliers in China that advertise batteries, but I can't find any in the USA market. Does anyone have suggestions on where I might find one in the USA?
I don't have a recommendation for a battery meeting those requirements.
Also note that the Tracker One and Monitor One limit charging based on the temperature inside the case and of the battery pack, respectively, so you'd also need to modify the Edge software to allow charging at higher temperatures.
The link above has a few notes on this - charging above 45°C is generally not recommended - anyone stating they can is likely exaggerating.
It's a chemistry/physics limit unfortunately.
HI @jdr2023 -
What capacity batteries are you looking at. I am currently looking into very stable batteries from SAFT to operate in hars conditions called SAFT MP
Maybe these can work for you or do you need larger capacity batteries? Alternatively reach out to SAFT with your exact requirements, they are quite helpful.
Thanks to everyone who's provided input to the question. Follow up for everyone, is there a power supply you have experience with that handles random voltage fluctuations to full drop outs for 1-5 seconds? I have a Boron in the field and suspect there are voltage fluctuations as the device has fully locked up and requires a power cycle. I have observed the device booting up without intervention 6 days after locking, it tells me the power is fully cycled. I was planning to use a battery but have also found that running on battery alone is not going to solve my problem as the device requires 5v to power the I2C devices on the bus (3.7v won't power them.)
If all you need to handle are dropouts of 1-5 seconds, a supercapacitor may be something to explore. I believe they make versions that operate at higher temperatures than LiPos typically operate at.
Hi, unrelated to the main concern of this thread, does the board have a watchdog or is one in your plans? It may save you some headaches.
If you decide to proceed with a battery, you may still have 5v with a 3.7v to 5v boost converter or similar.
A 3.7V to 5V boost converter is definitely an option and would be my first choice.
However you need to be very careful with 5V I2C devices. Gen 3 and later devices (nRF52 and RTL872x) are not 5V tolerant. This means that the I2C pull-ups can only be to 3V3 and not 5V, and if you are using I2C devices on a breakout, they must not have pull-up resistors. This is also dependent on your I2C devices being compatible with 3.3V as the high level when run at 5V.
The best option is to use an I2C level-shifter like a PCA9306, the MOSFET technique that Adafruit likes to use, or a two-channel bidirectional level-shifter breakout. This will allow the MCU to run the I2C bus at 3.3V but the I2C devices to use a true 5V I2C bus. This is also good if the I2C bus is long, approaching the 1 meter limit, because the bus is more noise-resistant at 5V.
hi @jdr2023 -
hmmm, I might be a bit confused. Is the device running off battery or is the battery for backup power supply only?
Where is 5V required?