Unless space is critical, I would install lead-acid batteries of suitable capacity, and a good quality dc to dc converter to provide the 5V to the Pi.
I would tend to avoid lithium batteries, (outdoors, I don't think they perform well over typical temperature ranges, and indoors they have more likelihood of catching fire than lead-acid. But those opinions may be out of date).
If I want reliability, I go for "trusted" brands, rather than the lowest possible cost items from Amazon and worse.
I usually use 24V (2 x 12V in series) batteries; partly to keep the current down, and partly because some of the system can use a nominal 24V directly. If you really need 2.5A for your Pi, you're looking at something like 2 x 40Ah batteries, which is rather large (and heavy!). As a first step I suggest you measure the actual power consumption, and add 10-20% margin, to determine the power you really need.
For the dc-dc converter, there are many choices; a DIN rail mount unit such as Meanwell DDR-15G-5 is good quality, easy to mount and has a limited amount of output adjustment so you can get a little more than 5V out of it. I have a couple of Pis getting power from a bigger device in this series. There are many other alternatives; some for mounting on PCBs, complete assemblies..
How are you proposing to charge the batteries? Meanwell (again) do a whole range of charger/power supply units which just need batteries connected to act as a simple UPS - something like the PSC-160B-C at the higher end, and DRC-40 at the lower. (I have a system using DRC-40 where the Pi has been running for nearly 9 years without a reboot).
I would tend to avoid lithium batteries, (outdoors, I don't think they perform well over typical temperature ranges, and indoors they have more likelihood of catching fire than lead-acid. But those opinions may be out of date).
If I want reliability, I go for "trusted" brands, rather than the lowest possible cost items from Amazon and worse.
I usually use 24V (2 x 12V in series) batteries; partly to keep the current down, and partly because some of the system can use a nominal 24V directly. If you really need 2.5A for your Pi, you're looking at something like 2 x 40Ah batteries, which is rather large (and heavy!). As a first step I suggest you measure the actual power consumption, and add 10-20% margin, to determine the power you really need.
For the dc-dc converter, there are many choices; a DIN rail mount unit such as Meanwell DDR-15G-5 is good quality, easy to mount and has a limited amount of output adjustment so you can get a little more than 5V out of it. I have a couple of Pis getting power from a bigger device in this series. There are many other alternatives; some for mounting on PCBs, complete assemblies..
How are you proposing to charge the batteries? Meanwell (again) do a whole range of charger/power supply units which just need batteries connected to act as a simple UPS - something like the PSC-160B-C at the higher end, and DRC-40 at the lower. (I have a system using DRC-40 where the Pi has been running for nearly 9 years without a reboot).
Statistics: Posted by stevend — Thu May 02, 2024 10:02 pm