A good quality car battery can set you back several hundred dollars and therefore, using the right charger is probably one, if not, the most important decision you can make in getting the best out of your battery – the expected runtimes and lifespan.
With that said, what charger should you use with an AGM battery?
Can you use a regular or conventional charger?
What should you even look for in a charger?
In this post, I share my tips for selecting a charger to keep your AGM battery topped up and how I charge the AGM batteries safely.
I hope you find them useful!
Quick Answer
Yes, you may be able to use a regular charger to charge an AGM battery.
Read the next section to learn what to look for in a regular charger that has the best chance of charging your AGM batteries!
When to Use a Regular Charger for an AGM Battery
You may be able to use a regular charger to successfully charge an AGM battery if it includes or checks out well against the list of recommendations.
1. Confirm that it is fit for use with charging AGM batteries. Consult the user manual or manufacturer’s website.
Make sure you select the appropriate setting when charging the AGM battery.
2. Check that the charger has a consistent pattern of positive reviews of excellent charging performance and reliability.
While I know I may be missing out on some potentially newer and reliable brands, I limit my purchases to 4/5 star genuine reviews.
3. Always choose a charger that automatically shuts off charging when the battery is full. It is not only convenient to use but is less likely to overcharge and damage the battery unlike when it is left up to the user to track the charging time which is the case with some chargers when fully charged
4. Look for safety protection features such as reverse polarity, and short-circuit protection.
While these features are standard in newer chargers, make sure that the charger has them to guard against potential damage to the charger in case of battery connections are wrongly connected or there’s a short circuit.
The Dangers of Using Any Regular Charger
Using just any charger without paying attention that it includes the features below or meets the criteria above risks partially charging the battery, possibly damage, and can also result in a shorter lifespan for your AGM battery!
Tips to Safely Charge an AGM Battery Without Damage
To charge an AGM battery safely, make sure the charger does not exceed the charging current, voltage, and battery temperature recommended by the battery manufacturer.
If you do so, the battery will likely overheat and can suffer irreparable damage.
Selecting the Recommended Charging Current
My advice is first, to make sure that the charging current that the charger uses is not too large for your battery capacity (Ah).
You’ll see manufacturers indicating in the manual that it “should not be used on batteries smaller than say 20 Ah”.
If you’re not sure, limit the charging set to up to 10% of its capacity. For a 200Ah battery, do not exceed 10% x 200Ah, or 20Ah charge rate.
Secondly, confirm that the charger is recommended for AGM batteries and that it is set to charge AGM batteries.
Note: some chargers are designed to charge only AGM batteries in which case there may be no additional setting required.
Selecting the Recommended Charging Voltages
Make sure the charger is set to charge to the recommended absorption and float voltage levels so that it is fully charged.
If you keep undercharging the battery, you risk the loss of battery capacity and deeply discharging it too which affects its lifespan.
The recommended float voltage for wet AGM batteries is usually in the range of (14.5-14.8V).
Consult the technical specifications document from your AGM battery manufacturer.
Some chargers have a simple selector switch or user-configurable setting for the battery type and behind the scenes, the charger auto-selects the recommended voltages for you without you having to do anything additional.
Other chargers may require that you manually select the recommended voltages yourself using dip switches or manually entering the voltages into the charger.
Maintaining Battery Temperature
The battery should be cool or warm to the touch, Make sure there’s enough air circulating around the battery bank to keep them running cool.
Keep them away from direct sources of heat. This way they last longer.
While the recommended temperatures to maintain the batteries may vary depending on the battery design, several manufacturers recommend a battery temperature of 5 °F (-15°C )-122°F (50 °C).
You can use an infrared thermometer to monitor this temperature.
Related Questions
Should you Charge an AGM battery with a Regular Charger?
You can use a regular, normal or conventional charger to charge your AGM battery provided it is designed for and is set to charge an AGM battery, and its charge rate is suited to charge your battery’s capacity (Ah).
Consult the charger manual for the battery capacity the manufacturer recommends for charging with the charger.
Closing Thoughts
To select the right charger for my battery, I would boil it down to confirm that it can charge AGM batteries and make sure it is set to charge AGM batteries, making sure that the charger current is not too high for the battery.
Last but not least, buy a charge with a consistent pattern of positive reviews of excellent charging performance and reliability.
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