Both UPS and Car batteries are available in lead-acid type as well as lithium-ion type. But despite the same technology used to produce these batteries, there are still many differences between them due to their application.
Most of the batteries available in the current market are still lead-acid based. Hence we will cover the difference between lead-acid based UPS batteries Vs Car batteries.
There are several types of Lead-acid batteries and some of the common types of batteries are mentioned below.
Classification based on configuration.
Flooded (also called Standard or Wet) battery
Sealed Type battery [also known as VRLA]
Classification based on application.
SLI Battery [Starting, Lighting and Ignition]
Deep Cycle Battery.
Both UPS and Car batteries are available in Flooded as well Sealed casing, hence to understand the difference between Car and UPS battery all you need to understand is the difference between SLI and Deep Cycle Battery.
SLI Battery (also called Cranking or Engine Battery) :
SLI stands for Staring, Lighting and Ignition. These types of batteries are developed to deliver a high burst of current for a short time [30 sec] while maintaining the battery terminal voltage of at least 12 Volt and then can be quickly recharged.
These batteries have relatively thin plates and a high plate count. This provides a large surface area of plates to react with the electrolyte to produce a higher amount of current quickly.
These batteries are also marked with CCA and CA ratings.
CCA rating of a battery:
In a cold environment, the ability of the battery to discharge current is low as compared to in a warm environment. CCA (cold cranking ampere) rating of a 12-volt battery, defines the ability of the battery to discharge current at -18°C (-0.4°F) for a time period of 30 sec while maintaining the battery terminal voltage equal to or greater than 7.2 volts.
CA rating of a battery:
Whereas CA (cranking ampere) of a 12-volt battery defines the ability of the battery to discharge current at 0°C (32°F) for a time period of 30 sec while maintaining the battery terminal voltage equal to or greater than 7.2 volts.
RA Rating of a battery:
RA or RCM (Reverse capacity minutes) rating of a 12-volt battery defines the ability of the battery to withstand the continuous discharge of 25 amperes current at 27°C (80°F) before its terminal voltage drops below 10.5 voltage.
With all these advantages SLI batteries come with one disadvantage, which that is these batteries are not designed to repeatedly deep discharge.
SLI batteries are available in both flooded (wet) type configuration and sealed [VRLA] configuration.
Deep cycle batteries are designed for repeatedly deep discharging at a constant discharge rate and repeatedly charging. Deep cycle batteries are designed with a lower number of plates which are thicker as compared to SLI batteries (also called cranking or engine batteries).
Deep cycle batteries are also available in both flooded and sealed configurations. Deep cycle batteries are generally rated in Ah (ampere-hour), whereas they also have CCA, CA and RA ratings. But due to the application of this type of battery, these ratings are not defined.
Car battery Vs UPS Battery
UPS batteries are DEEP CYCLE type battery that provides low but steady current so that they can serve power backup for longer periods. On the other hand, Car batteries are DUAL PURPOSE type batteries, these batteries are designed to provide a balanced combination of starting (SLI type) and DEEP CYCLE. The car battery is designed to provide a high starting current but can also need to withstand a longer discharger period than an SLI type battery.
There are also some more noticeable differences between CAR and UPS batteries.
Car batteries are not designed for repeated deep discharge and their life will be reduced when subjected to this. Whereas UPS batteries are designed to discharge repeatedly without any effect on their lifetime.
The Ah rating of CAR batteries is relatively low as compared to UPS batteries. The Ah rating of car batteries varies from 60Ah to 85Ah, whereas the Ah of UPS batteries varies from 100Ah to 200Ah.
Flooded batteries are more prone to fires and explosions than a sealed battery and due to safety reasons flooded type batteries are not recommended for cars and other vehicles. Hence the car batteries are generally sealed types whereas UPS batteries are both flooded and sealed types.
Car batteries are also rated in craking ampere (CA and CCA rating) whereas UPS batteries are only made in Ah rating and Class rating.
UPS batteries can be discharged up to 90% without any damage whereas Car batteries are meant to ideally discharge up to 5%. And that’s the reason you should not leave your car light.
With all the differences mentioned above still, you can still use your UPS battery to charge your CAR battery.