On 04/12/2020 10:03, NY wrote:
> "The Natural Philosopher"  wrote in message
> news:rqd0hr$r21$2@dont-email.me...
>> On 04/12/2020 08:08, Mike Scott wrote:
>>> any suggestions for a good ups for a 24/7 pi server please?
>>
>> You could do worse than a continuously charged 11V lithium pack or 12v
>> car battery  and a 5V switched regulator.
>>
>> How many amps does a Pi draw?
>> How long do you want it to stay up?
>
> I happen to have a large battery that is charged from a 5 V USB charger
> (Micro USB input) and supplies 5 V (on a USB-A output). I thought I
> could use this as a UPS - particularly to keep a Pi going for brief < 5
> second power cuts that were plaguing our village (overhanging trees
> touching the high voltage feed to a substation).
>
> But sadly this battery cuts off its output as soon as either an input
> cable is plugged in or 5V is supplied at that input (I forget which),
> and this rather scuppers that plan. :-(

There are ways around this sort of thing, in hardware.
Personally I would probably build my own UPS.

A decent 12v battery, a 5v switched regulator and a constant voltage
trickle charger.

Batteries and trickle chargers are standard automotive kit. a 5V
switching regulator is something that is most easily sourced as an RC
model spare, where they are used to step down flight battery power to
servo and receiver voltages e.g.

https://hobbyking.com/en_us/5v-5a-ubec-2-5s-lipoly-7-2-21v.html

Connect the trickle charger to the mains, the battery to the trickle
charger and the SBEC to the battery and the Pi to the SBEC....

--
If I had all the money I've spent on drink...
..I'd spend it on drink.

Sir Henry (at Rawlinson's End)

--- SoupGate-Win32 v1.05