28/10/2022

## What should the specific gravity of a battery be?

The electrolyte in a fully charged battery is usually 1.26 times as heavy as an equal volume of pure water when both liquids are at the same temperature. The battery electrolyte would therefore be described as having a “Specific Gravity” of 1.260 meaning that its weight is 1.260 times the weight of pure water.

What happens if specific gravity of battery is low?

Low battery gravity will reduce the effectiveness of the battery in terms of its charge capacity and the extent of its draining. However, you also need to understand that high gravity will result in battery wear and destruction of its plates and so you should maintain your battery gravity between 1.180-1.240.

### What is the specific gravity of a 6 volt battery?

12 volt – 6 volt Battery Maintenance & Charging Guide

State of Charge Specific Gravity Voltage
6V
100% 1.265 6.3
75% 1.225 6.2
50% 1.190 6.1

What is the specific gravity of 50% charge battery?

Fully charged battery specific gravity is 1.28. 100% charged – 1.280. 75% charged – 1.240. 50% charged – 1.200 (1.19).

#### Why specific gravity is important in battery?

Specific gravity (SG) is very important because it’s the most direct indicator of battery state of charge. State of charge (SoC) is directly proportional to specific gravity so if we can measure the SG we can instantly determine the SoC.

How accurate is a battery hydrometer?

Hydrometers are at best accurate to +/-0.005 points. Voltage can be used to estimate the state of charge, however, caution must be taken when interpreting voltage readings.

## What is a good battery hydrometer reading?

A hydrometer reading of 1.265 indicates a fully charged battery. A 75% charge is 1.225. Approximately 1.190 is half-charged, 25% is 1.155 and 1.120 indicates complete discharge. Each cell of the battery should be checked.

What is the specific gravity of a fully charged 12v battery?

1.280
The specific gravity, SG, of the electrolyte in each cell of a battery shows the battery’s state of charge: Fully charged, SG = 1.280.

### How do you tell if a battery has a dead cell?

1. Reading 0 volts, chances are the battery experienced a short circuit.
2. Cannot reach higher than 10.5 volts when being charged, then the battery has a dead cell.
3. Fully charged (according to the battery charger) but the voltage is 12.4 or less, the battery is sulfated.

How much variance is acceptable in battery cell readings with a hydrometer?

A fully charged battery with well mixed electrolyte should show hydrometer reading on all cells to be within 25 points of each other. If a discrepancy greater than this persists after an equalizing (extended) charge, the battery should be checked by an experienced battery technician.

#### How do you check battery gravity with a hydrometer?

Insert the Hydrometer Press on the bulb that acts as a syringe. You should see fluid filling the hydrometer. Continue to squeeze the bulb until the battery electrolyte solution fills the device to the maximum level. This device tests each cell by measuring the specific gravity of the fluid.

Can you repair a dead cell in a battery?

While you can fix a dead cell in a car battery by reconditioning it, it’s extremely dangerous. Acid burns are awful, so try this at your own risk and please be careful! That said, if at any point you feel uncomfortable or unsure, contact a professional to complete the process.

## What voltage should a 12 volt battery read when fully charged?

12.6 volts
The standard automotive battery in today’s vehicles is a 12-volt battery. Each battery has six cells, each with 2.1 volts at full charge. A car battery is considered fully charged at 12.6 volts or higher.