How do I power 12v electronics off a 12v battery that is under charge?

I want to power a few electronics (Linksys Router, Raspberry Pi 4B, 2.4ghz wifi amplifier) off a 12v deep cycle battery. The battery will be charged by a Morningstar Duo PWM charge controller and 3 100w Windy Nation solar panels. I guess I'm worried about the electronics receiving too high a voltage when the battery is being charged. Is there something I can add to isolate the electronics from the high voltage of the battery charging?
This is for a solar powered robot that I can log in to from 1000 miles away and drive around, etc.
The batteries I'm using are Deka 8A22NFs. I will be using 4 batteries total. 1 to power the wheels and 3 to power the Raspberry Pi, router, wifi amplifier, iPhone (4g connection in case wifi stops working) and a camera. I'm using the Morninstar Duo since it can power two battery circuits separately and the motors cause a voltage drop. So I am keeping those separate from the electronics.
This is for a solar powered robot that I can log in to from 1000 miles away and drive around, etc.
The batteries I'm using are Deka 8A22NFs. I will be using 4 batteries total. 1 to power the wheels and 3 to power the Raspberry Pi, router, wifi amplifier, iPhone (4g connection in case wifi stops working) and a camera. I'm using the Morninstar Duo since it can power two battery circuits separately and the motors cause a voltage drop. So I am keeping those separate from the electronics.
Comments
Boost always takes lower voltage and converts to higher voltage.
When you want 13.8 (variable) to 13.8 volts, then you want a Buck Boost converter... It has both sections in the switching power supply, and can take a wide range of input voltages around your 13.8 volts output setpoint (as an example). Besides Amazon, eBay and other places have lots of options out there.:
https://www.amazon.com/s?k=dc+to+dc+buck+boost
[2-Pack] Adjustable DC-DC Buck Boost Converter Automatic Wide Voltage Regulator XL6009 DC to DC 5-32 V to 1.25-35 V Voltage Module
WHDTS DC Buck Boost Power Supply Module DC 5V-30V to DC 0.6V-30V 35W 4A CVCC Adjustable Automatic Step UP Down Voltage Converter LCD Display
On ebay, search for buck boost converter... But be careful, some say step-down buck boost, or step-up buck boost converter... The couple I checked, appeared to NOT be buck boost, but just buck OR boost.
For a 12 volt battery bank (Lead Acid), you want something that works from ~10.5 to 16+ volts and outputs 13.8 volts (or whatever you choose).
Don't get a really large converter--They are like AC inverters, they have a certain amount of Tare Loss (switching losses, even with no loads)--So you don't want 10 Watts "standby" power consumption on a 5 Watt output supply (again, just a made up example).You could, for example, have a small unit to power the electronics, and a separate converter with remote on/off for operating the drive wheels and other high drain devices.
-Bill
Most of those things would be under 10 watts, I would think they would work for them if you are worried. I thought the 'Pi' had a rather large acceptable input voltage, but it's been years since I looked at them...
Something like this, just lose the extra voltage as heat, may require a heat sink;
https://www.newark.com/texas-instruments/lm340t-12-nopb/linear-voltage-regulator-12v-to/dp/41K4771
- Assorted other systems, pieces and to many panels in the closet to not do more projects.