Pete’s team outlines the basics behind the heart of your electric golf cart. Your golf cart batteries! Whether they are in good working order or not will directly reflect the performance or your golf cart. Which could also cause issues or false issues with your charging system because of low voltage or an internal short in the battery bank. We have set this blog post up for informational purposes to try and answer frequently asked questions via telephone conversations over the years… You can scroll down the list of questions and answers to hopefully shine some light on your problem or worries and hopefully it will be helpful in determining your current issue with your Trojan Golf Cart Batteries or really this information will apply to any “Flooded” Golf Cart Battery not really specific to one brand though should you need a new set of Trojan Golf Cart Batteries for your golf cart, click here.
Frequently Asked Questions
Measurements & Troubleshooting
Question: How can I tell if a flooded battery is bad?
To determine if the battery in a system is experiencing a problem, disconnect all electrical loads, fully charge the batteries then disconnect all charging sources. Allow each battery in the system to stand on open-circuit for about one hour. Measure the voltage of each battery. If the battery voltage spread exceeds .15 volts for a 6-volt battery, or .22 volts for a 12-volt battery a problem is indicated. Battery voltage alone does not confirm a problem. When the voltage spread indicates a problem, confirmation is accomplished by taking electrolyte specific gravity readings using a hydrometer. If the specific gravity readings show a spread greater than .030 (30 points), give the batteries an equalization charge and re-test.
Question: How can a flooded battery’s state of charge be accurately measured?
The state of charge of a lead acid battery is most accurately determined by measuring the specific gravity of the electrolyte. This is done with a hydrometer. Battery voltage also indicates the level of charge when measured in an open circuit condition. This should be done with a voltmeter. For an accurate voltage reading, the battery should also be allowed to rest for a period of one hour minimum in order to let the voltage stabilize.
Question: How far can I tilt my batteries?
For flooded batteries, 22 degrees from vertical is the maximum recommended tilt. AGM and Gel batteries can be operated vertically or horizontally.
Question: Can I reduce my maintenance by not gassing my flooded batteries?
You will reduce the frequency of watering, but will cause a condition known as stratification where the specific gravity of the electrolyte is light at the top of the battery and heavy at the bottom. This condition results in poor performance and reduced battery life.
Question: What is used to clean a battery and neutralize the electrolyte?
A solution of baking soda and water. Use 1 cup of baking soda for every gallon of water.
Question: What is the specific gravity of a fully charged flooded battery?
A hydrometer reading of 1.277 or greater indicates full charge for most Trojan batteries. This value is based upon a specified temperature of 80°F (27°C). For temperature correction values, see the “Temperature” section of this FAQ.
Question: What is the correct Specific Gravity (SG) of the Trojan Premium Line? I was told that Trojan changed the SG value for the Premium Line. Is this true? How do I determine the correct Specific Gravity of the Trojan Premium Line battery I already have purchased?
Yes, Trojan changed SG values of the Premium Line in March 2012 to avoid confusion over correct SG values for the Premium Line compared to the Signature Line. However, this change does not have any impact on life cycle performance. Trojan Premium Line batteries manufactured prior to March, 2012 have nominal SG of 1.260 while those produced after March 2012 have nominal SG of 1.280. To determine the date of manufacture, refer to the date code on the negative terminal which consists of a letter and a number. The letter refers to the month and the number refers to the year. A2 = January 2012, B2 = February 2012 and C2 = March 2012 etc…
Trojan Golf Cart Battery Date Codes of Manufacturing
Question: How do you read the date codes on the batteries?
Negative Terminal- Shipping Date. This code indicates the month and year when the battery was shipped out of our factory. LETTER stands for the month, A to L (A=January, B=February, C=March, and so on); NUMBER is the last digit of the year.
- A battery with “G4” on the negative.
- “G4” means that it was shipped from our factory around July of 2014.
Temperature Factors & Effects
Question: How does temperature affect the performance of my batteries?
At higher temperatures (above 80º F (27º C)) battery capacity generally increases, usually at the cost of battery life. Higher temperatures also increase the self-discharge characteristic. Colder temperatures (below 80º F (27º C)) will lower battery capacity and prolong battery life. Cooler temperatures will slow self-discharge. Therefore, operating batteries at temperatures at or slightly below 80º F (27º C) will optimize both performance and life.
Question: How do I determine my battery capacity when it is colder/hotter?
Battery capacity is basically a linear relationship. A good rule of thumb is that for every 15º F (9º C) above 80º F (27º C), capacity is increased by 10% and for every 15º F (9º C) below 80º F (27º C), capacity is reduced by 10%.
Question: How do I account for temperature when taking my gravity readings?
Temperature will affect specific gravity readings. As temperature increases, the electrolyte solution expands and as temperature decreases the electrolyte solution contracts. As a result, it is a good practice to temperature correct specific gravity readings. Here are the relationships Trojan recommends using:
Every ten degrees above 80º F (27º C) add 4 points to the hydrometer reading.
Example: @ 90º F (32º C) the hydrometer reads: 1.250 the actual reading: 1.250 + .003 = 1.253.
For every ten degrees below 80º F (27º C) subtract 4 points from the hydrometer reading.
Example: @ 70º F (21º C) the hydrometer reads: 1.250 the actual reading: 1.250 – .003 = 1.247.
Question: How much should I compensate the charge voltage for temperature?
Temperature will affect voltage readings. As temperature increases, voltage decreases. Conversely, as temperature decreases, voltage increases. Here are the relationships:
Trojan recommends using the following: For every 1º F below 77º F add 0.0028 volts per cell or for every 1 C below 25º C add 0.005 volts per cell to the charger voltage setting.
1: A 12 volt battery @ 70º F. The recommended charging voltage at 77º F is 14.8 volts. The adjusted charging voltage is 14.8 + (6 cells * 7 degrees below * 0.0028) = 14.92 volts.
2: A 12 volt battery @ 21º C. The recommended charging voltage at 25º C is 14.8 volts. The adjusted charging voltage is 14.8 + (6 cells * 4 degrees below * 0.005) = 14.92 volts.
For every 1º F above 77º F subtract 0.0028 volts per cell or for every 1º C above 25º C subtract 0.005 volts per cell to the charger voltage setting.
1: A 12 volt battery @ 85º F. The recommended charger voltage at 77º F is 14.8 volts. The adjusted charging voltage is 14.8 – (6 cells * 8 degrees above * 0.0028) = 14.67 volts.
2: A 12 volt battery @ 29.5º C. The recommended charger voltage at 25º C is 14.8 volts. The adjusted charging voltage is 14.8 – (6 cells * 4.5 degrees above * 0.005) = 14.67 volts.
Question: Is there a maximum temperature for charging my batteries?
When charging lead acid batteries, the temperature should not exceed 120ºF. At this point the battery should be disconnected from all charging sources and loads in order to cool before resuming the charge process.
Hopefully this information was helpful to learn more or continue reading about your golf cart batteries and how to take care of them click here.
Should you come to the conclusion you will need to purchase new golf cart batteries you might find this article helpful.
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