Do car batteries work well as a backup battery (not counting the explosion of course)? I assumed they would require an alternator or else they wouldn’t hold much of a charge. I know very little of cars obviously.
A typical UPS (uninterruptible power supply) that’s used for computers/servers is basically powered by a small car battery (12v nominal voltage, lead acid battery).
Sump pump battery backups are also typically a lead acid battery, though they’re typically a “deep cycle marine” battery, which basically means they store more energy than an equivalent sized car battery.
An alternator is actually just a small generator! It converts rotation (from the engine spinning a pulley) to ~13v to ~15v DC at up to some level of current spec (usually 50Amps or more). Some of that goes to the battery to charge it, and some goes to powering accessories in the car.
A UPS simply has an AC to DC charging circuit to perform that function, converting mains electrical voltage (~120v AC in the USA, varies by country) to ~14v DC.
To add the little bit I know to the comments above.
Car batteries are not the same as AGM (often sold as scooter or marine batteries) or newer LiFePO4 batteries.
While I think AGM and car batteries both are lead acid, car batteries are designed to have one big discharge to start an engine and then recharge from an alternator. The other batteries are designed for a slower discharge over time.
The batteries commonly used in battery backups were usually AGM type, and now the LiFePO4 (usually used for solar) are starting to be used for backups and are much safer (I think they don’t off gas as much?).
The original post was a picture of a solar battery, but an SLA (sealed lead acid, of which some are agm) one from harbor freight.
They’re cheap, but fine. You should have a proper battery maintainer or smart trickle charger attached. A good one will tell you if there’s a fault with the battery.
Do car batteries work well as a backup battery (not counting the explosion of course)? I assumed they would require an alternator or else they wouldn’t hold much of a charge. I know very little of cars obviously.
A typical UPS (uninterruptible power supply) that’s used for computers/servers is basically powered by a small car battery (12v nominal voltage, lead acid battery).
Sump pump battery backups are also typically a lead acid battery, though they’re typically a “deep cycle marine” battery, which basically means they store more energy than an equivalent sized car battery.
Oh, this makes more sense. I never thought about a powered UPS as being similar to a car battery with an alternator.
An alternator is actually just a small generator! It converts rotation (from the engine spinning a pulley) to ~13v to ~15v DC at up to some level of current spec (usually 50Amps or more). Some of that goes to the battery to charge it, and some goes to powering accessories in the car.
A UPS simply has an AC to DC charging circuit to perform that function, converting mains electrical voltage (~120v AC in the USA, varies by country) to ~14v DC.
To add the little bit I know to the comments above.
Car batteries are not the same as AGM (often sold as scooter or marine batteries) or newer LiFePO4 batteries.
While I think AGM and car batteries both are lead acid, car batteries are designed to have one big discharge to start an engine and then recharge from an alternator. The other batteries are designed for a slower discharge over time.
The batteries commonly used in battery backups were usually AGM type, and now the LiFePO4 (usually used for solar) are starting to be used for backups and are much safer (I think they don’t off gas as much?). The original post was a picture of a solar battery, but an SLA (sealed lead acid, of which some are agm) one from harbor freight.
🤯
They’re cheap, but fine. You should have a proper battery maintainer or smart trickle charger attached. A good one will tell you if there’s a fault with the battery.