Okay, to summarize. AA battery backup power for network equipment.
- AA batteries can deliver 2500 mAh per cell.
- Thus, 8 AA batteries can deliver 20 A. Plenty good power for backing up network equipment.
- The best choices on battery chemistry are alkaline and Nickel
Metal-Hydride.
- Rechargeable alkaline does not have good capacity and life.
- You can use the LTC4412 IC from linear tech for gracefully switching to backup power.
20171118/DuckDuckGo electronics switch between aa power and dc input
outage
20171118/DuckDuckGo electronics switch between AA battery power and dc
input outage
20171118/DuckDuckGo AA battery 12 volt power supply
Somewhat on track, but it doesn’t provide a DC pass-through for line power.
20171118/https://www.superbrightleds.com/moreinfo/battery-and-cps-compact-power-supplies/12v-dc-battery-power-supply-8-cell-aa-battery-holder/934/
20171118/DuckDuckGo electronics switch to backup power supply when main supply goes out
20171118/http://www.electronicdesign.com/power/fet-or-circuit-switches-between-main-and-backup-supplies
20171118/https://electronics.stackexchange.com/questions/113233/switching-between-backup-battery-and-main-power-supply
20171118/http://www.edaboard.com/thread183013.html
20171118/DuckDuckGo LTC4412 IC
broken/20171118/http://www.linear.com/docs/en/datasheet/4412hvfs.pdf
20191128/https://www.analog.com/media/en/technical-documentation/data-sheets/4412fb.pdf
20171118/DuckDuckGo FDN306P
20171118/http://morrow.ece.wisc.edu/IEEE/2010/Datasheets/Fairchild/FDN306P.pdf
20171118/https://www.mouser.com/ProductDetail/ON-Semiconductor-Fairchild/FDN306P/?qs=GeD7q9OHBPy9Kkc110idSQ%3d%3d
You’re in luck. This handy IC will do it all for you for circuits that require 300 mA of current or less.
20171118/DuckDuckGo LTC1579
20171118/http://www.linear.com/product/LT1579
“1579f.pdf”:
20171118/http://www.linear.com/docs/3544
Ah, I see. But 300 mA is a bit low on the current side for the devices I plan on powering. 700 mA would work better. By contrast, the separate TI switch circuit can handle current up to 2.6 A. I’m going to have to carefully look at the power supplies and inputs of my devices to be sure.
- But, remember this: 20 Ah / 1 A = 20 hours
Okay, more details. Make sure you select that MOSFET carefully to handle the voltage and current. Generally, you have to over-specify the limits to get what you want. Look at those specification graphs very carefully to make sure you’re in range.
20171118/https://en.wikipedia.org/wiki/Schottky_diode
20171118/DuckDuckGo battery power management switch mosfet 12 v
This is useful general information on using MOSFETs.
20171118/http://www.onsemi.com/pub/Collateral/AND9093-D.PDF
20171118/DuckDuckGo load switch mosfet 12 v
This is it for the MOSFET, i.e. load switch.
20171118/https://www.electronicspoint.com/threads/using-mosfets-to-switch-a-12-volt-2-amp-load.263531/
20171118/http://www.digikey.com/product-detail/en/FQP13N06L/FQP13N06L-ND/1053954
20171118/DuckDuckGo FQP13N06L
20171118/http://www.mouser.com/ds/2/149/FQP13N06L-244291.pdf
Be careful with the capacitor selection and configuration, in order to get proper damping, avoid overshoot voltage and current, and keep the power transition smooth.
20171118/DuckDuckGo application note 88 linear electronics
20171118/http://cds.linear.com/docs/en/application-note/an88f.pdf
20171118/DuckDuckGo 8 AA battery backup power supply for router
Yeah, it sure looks like it is popular for people to use conventional AC plug-in UPS for “everything.”
20171118/https://batterybackuppower.com/2016/07/25/8-hour-and-24-hour-battery-backup-kit-for-home-modems-routers-and-voip-devices-released/
20171118/http://www.practicallynetworked.com/networking/082307ups.htm
20171118/https://raspberrypi.stackexchange.com/questions/1360/how-do-i-build-a-ups-like-battery-backup-system
Too expensive ($120), and it doesn’t meet my needs.
20171118/DuckDuckGo mini ups and power sensor
20171118/https://avtech.com/Products/Sensors/MUPS.htm
20171118/DuckDuckGo how long can 12 v router run off of AA batteries
20171118/DuckDuckGo how long can 12 v router run off of 8 AA batteries
Yes, you do want 7 Ah, 10 Ah, or 26 Ah for powering network equipment, otherwise your run time will be too short to be interesting.
20171118/http://www.instructables.com/id/Running-a-DSL-Router-from-12v-Battery-Anti-Loadshe/
20171118/https://en.wikipedia.org/wiki/Nickel%E2%80%93metal_hydride_battery
20171118/https://en.wikipedia.org/wiki/AA_battery
20171118/https://en.wikipedia.org/wiki/Alkaline_battery
20171118/https://en.wikipedia.org/wiki/Rechargeable_alkaline_battery
Interesting.
20171118/http://www.instructables.com/id/Convert-Battery-Powered-Electronics-to-Run-on-AC/