LISEN 90W USB C Car Charger USB C Fast Charge,45W PD&QC3.0 Fast Car Charger
For this charger that requires a 24 watt, 2.0 amp input.
16 Bay Battery Charger AA AAA for NiMH Rechargeable Batteries
Type-C QC/PD 24W Quick Charge Input
This means in an emergency I can charge 16 AAs at once in a car, how much does it drain the car battery if the car isn’t running?
How many batches of 16 batteries would you feel safe charging off of a parked car battery? Is all this safe for the charger and the NiMH batteries?
Here are the links to the two products.
car adapter-- Amazon.com
THe capacity of a typical car battery is around 1000 WH.
The capacity of a typical AA cell is around 3 WH. 16 AA cells would have a combined capacity of 48 WH.
We have to guess a little at the overall charging efficiency of the system. For fully discharged NiMH cells the losses in the cell are somewhere around 10%-20% depending on which source you believe and what cutoff algorithm is used by the charger (since losses approach 100% as the cell becomes fully charged). Cheap 12v to USB converters are lossy as are most NiMH chargers. We could guess at 50% total system losses – 12v-to-USB, NiMH-charger, and in-cell losses combined.
That would mean 98 wh from the 12v car battery would be required to charge 16 fully discharged AA cells, which is about 10% of the 12v car battery’s capacity.
You could run probably 6-8 batches +/- before the car wouldn’t start depending on the age of the car battery, temperature, and other factors.
In most real world scenarios at least some of the AA cells will be only partially discharged which means they will require somewhat less energy to charge.
Very nice description, thanks, in much of my emergency preps I have gotten to where I prefer AA and AAA batteries as the foundation for most things and this sounds like a very doable way to charge 16 AAs at once.
Some newer vehicles have rather small batteries. Some are only 35ah. So it pays to know what you are working with. This is for weight reduction for CAFE.
Typical starting batteries dont like deep cycles either.
Keep this in mind when you replace the battery and see if there is room in the tray for a larger one. My accord came with a 51r and i found a 35 drops right in.
Dodge pickup came with a 27 and a d31 agm 120ah fits after a bit of trimming on the plastic tray.
This is important when i run a mobile radio and vrs all day.
I would advise utilizing a test at some point so you know what you’re up against. Monitor battery voltage while doing that test.
Some cars leave the power outlet live when the vehicle is off.
With some it may stay live for a few or up to 10 minutes.
With others it won’t be live at all with the ignition in the off position.