On 11/18/19 6:14 PM, Tadd Torborg via TriEmbed wrote:
I'm using a 2.5amp-hour 12v Gel Cel - PS-1220 Costs $10 in quantity 10.
https://www.amazon.com/gp/product/B077Y9FT5K
I'm using it as a backup supply to keep a Raspberry PI alive if the
main 14.2v supply goes away. I have the two main and battery diode
ORed through a bridge rectifier to a DROK switcher supply which
outputs 5.2v on USB to run the Raspberry PI 4B. Another leg of the
bridge rectifier provides 13.8v only from main supply, which I run
through a 10watt 50ohm resistor back to the +DC lead on the gel cel.
This gives me a really cheap trickle charger.
If the battery is warmer than room temp a schottky or regular diode in
series will avoid exceeding the recommended maximum standby charge
voltage. The 13.8 limit is for 25C. Reference here
<https://www.powerstream.com/SLA.htm>.
Pete
Objectives:
1. feed stable power to the Raspberry PI with 5.2v even if main supply
glitches or goes off
2. run off a main power supply supply which can also feed power to
12-15v peripherals
3. have backup capability for at least several hours of running the
Raspberry PI 4 and it's daughter cards.
4. be cheap
5. be easy to get now and into the future
Details on the trivial circuit are here:
http://tarpn.net/t/builder/builders_robust_power_for_raspberry_pi.html
Tadd / KA2DEW
On November 18, 2019 at 12:41 PM, Robert Henry via TriEmbed
<[email protected]> wrote:
(--sending from correct e-mail this time--)
Hey all,
*Question for group*: I'm curious what battery packages folks in this
group use for their projects? If there is quite a variety - perhaps
offer your favorite/most flexible.
*Background:* I'm currently selling ~12v LiFePO4 battery packs (4s1p)
that I had as surplus from a consumer product. Product launched with
limited success, but the battery packs are selling well enough that
I'm considering sourcing other chemistries / configurations. Would
like to keep with the embedded project market to start (that is -
capacities less than 100 Watt-Hours).
Any insight would be greatly appreciated. Thank you!
Rob Henry
Rob Henry
LT Cage Productions, LLC
ph: +1.919.245.7684
_______________________________________________
Triangle, NC Embedded Computing mailing list
To post message: [email protected] <mailto:[email protected]>
List info:
http://mail.triembed.org/mailman/listinfo/triembed_triembed.org
TriEmbed web site: http://TriEmbed.org
To unsubscribe, click link and send a blank message:
mailto:[email protected]?subject=unsubscribe
_______________________________________________
Triangle, NC Embedded Computing mailing list
To post message: [email protected]
List info: http://mail.triembed.org/mailman/listinfo/triembed_triembed.org
TriEmbed web site: http://TriEmbed.org
To unsubscribe, click link and send a blank message:
mailto:[email protected]?subject=unsubscribe
_______________________________________________
Triangle, NC Embedded Computing mailing list
To post message: [email protected]
List info: http://mail.triembed.org/mailman/listinfo/triembed_triembed.org
TriEmbed web site: http://TriEmbed.org
To unsubscribe, click link and send a blank message:
mailto:[email protected]?subject=unsubscribe
