541-474-4421 M-F 6:30 am-4:30 pm PST
MENU Menu Icon

5 Battery Types Explained - Sealed, AGM, Gel

With all the different kinds of batteries on the market, it can be difficult to choose the right type for your application. We recommend that you take a few moments to find out more about the 5 most common types of batteries.

1. Flooded Batteries

This is the traditional engine start, tractor and deep cycle-style battery. The liquid electrolyte is free to move in the cell compartment. The user has access to the individual cells and can add distilled water as the battery dries out. Popular uses are engine starting and deep cycle designs.

For this type of battery the typical absorption voltage range 14.4 to 14.9 volts; typical float voltage range 13.1 to 13.4 volts.

Flooded batteries are common and found in many applications, such as automotive starting batteries, motorcycle batteries, ATV batteries, golf carts batteries, and flooded batteries for solar and emergency backup systems.

2. Sealed Batteries

This term can refer to a number of different constructions, including only a slight modification to the flooded style. In that case, even though the user does not have access to the cell compartments, the internal structure is still basically the same as a flooded battery. The only difference is that the manufacturer has ensured that a sufficient amount of acid is in the battery to sustain the chemical reaction under normal use throughout the battery warranty period. Other types of lead acid batteries are also sealed, as explained below. Very popular uses are engine starting and limited starting/deep cycle applications.

For this type of battery the typical absorption voltage range 14.2 to 14.7 volts; typical float voltage range 13.1 to 13.4 volts.

3. VRLA Batteries

This stands for Valve Regulated Lead Acid battery. This is also a sealed battery. The valve regulating mechanism allows for a safe escape of hydrogen and oxygen gasses during charging.

For this type of battery the typical absorption voltage range 14.2 to 14.5 volts; typical float voltage range 13.2 to 13.5 volts.

VRLA batteries are common and found in many applications, such as medical mobility scooters batteries and toy and alarm batteries.

4. AGM Batteries 

The Absorbed Glass Mat construction allows the electrolyte to be suspended in close proximity with the plates active material. In theory, this enhances both the discharge and recharge efficiency. Actually, the AGM batteries are a variant of Sealed VRLA batteries, just a more advanced design. Popular usage includes high performance engine starting, power sports, deep cycle, solar and storage batteries.

For this type of battery the typical absorption voltage range 14.4 to 15.0 volts; typical float voltage range 13.2 to 13.8 volts.

AGM batteries are common and found in many applications such as RV batteries, boat batteries, motorcycle batteries, ATV batteries, and UPS & Telecom batteries for generators.

5. GEL Batteries

The Gel Cell Battery is similar to the AGM battery style because the electrolyte is suspended, but different because technically the AGM battery is still considered to be a wet cell. The electrolyte in a gel cell battery has a silica additive that causes it to set up or stiffen. The recharge voltages on this type of cell are lower than the other styles of lead acid battery. This is probably the most sensitive cell in terms of adverse reactions to over-voltage charging. Gel batteries are best used in VERY DEEP cycle application and may last a bit longer in hot weather applications. If the incorrect battery charger is used on a Gel Cell battery, poor performance and premature failure is certain. Battery chargers with gel profile will have information either on the unit, or in the manual, about gel compatibility.

For this type of battery the typical absorption voltage range 14.0 to 14.2 volts; typical float voltage range 13.1 to 13.3 volts.

Note about Gel Batteries: It is very common for individuals to use the term Gel Cell when referring to sealed, maintenance-free batteries, much like one would use Kleenex when referring to facial tissue or "Xerox machine" when referring to a copy machine. Be very careful when specifying a charger. More often than not, what someone thinks to be a Gel Cell is really a sealed, maintenance-free VRLA or AGM-style battery. Lean more about differences between gel cell vs an AGM battery.

Gel batteries are not as common as AGM batteries, but are often found in deep discharge situations such as wheelchair and medical mobility batteries, trolling motor batteries, and RV deep cycle batteries.

Need a new high performance battery?
Choose Your Battery

Was this information helpful? Sign up to Get Updates and Offers.

Email address should be formatted
We respect your rights to privacy and will not share your email information with anyone ever.
8 people commented, Tech, Danny Foreman, Colin Bale, John Hill, and 4 others
This article is rated 5.0 out of 5
For Questions and Tech Support, please submit your question with our Support Page.

Should contain only letters, numbers, and (' - .)!

   1   2   3   4   5

  • Danny Foreman
    why is there 4 gel batteries on an international truck for the sleeper and 4 of the same to crank the truck . Can an acid filled battery be put for the truck only and leave the gel in the rear?

    Reply  •  Rated article 5  •  August 8, 2022 at 12:08 pm
    • BatteryStuff Tech
      Danny - It would be best to talk to the service center that services your truck for the best answer. I would assume the four sleeper batteries are meant for deep cycle purposes and they used gel because gel batteries have a greater cycle life and can handle excessive discharge better than a flooded or AGM battery. Most starting batteries are flooded or AGM as gel batteries typically do not have high cranking amps, so you will not see many gel batteries used in starting applications. If you are looking to put acid-filled batteries in the rear you would need to ensure the gases they generate can be exhausted outside and the charging system can be configured towards flooded as gel batteries typically charge at a lower voltage level.

      Reply  •  Rated article 5  •  August 10, 2022 at 7:39 am
  • Colin Bale
    My controller does not show AGM what charge setting should I use.

    Reply  •  Rated article 5  •  July 9, 2022 at 7:43 pm
    • BatteryStuff Tech
      I would suggest looking at the specification sheet for your AGM battery. Most batteries will have a charge and float voltage range suggested by the manufacturer. I would recommend looking at that range and seeing if one of the charging profiles available on your controller charges within the suggested ranges. If the controller does not it might be time to update to a controller that falls within the recommended ranges.

      Reply  •  Rated article 5  •  July 14, 2022 at 9:53 am
  • John Hill
    Hi I have a solar controller with ,sealed ,gel ,flooded, modes written on it. I have AGM batterys, do you know which one of the 3 I should be using? ...thank you

    Reply  •  Rated article 5  •  June 16, 2020 at 10:12 pm
    • BatteryStuff Tech
      AGM's are a sealed battery, so I would assume that the sealed setting would be the appropriate setting. However, assumptions can get you into trouble, so I would suggest pulling the manual for your controller and verify its voltage settings. Most manuals will give you the charge voltages for each profile, then you can verify that your controller will charge the battery within the battery manufacturers voltage recommendations. Those recommendations are typically printed on the side of the battery.

      Reply  •  Rated article 5  •  June 18, 2020 at 9:54 am
  • Judy Forman
    I have a sealed-type (MF) WHAT KIND OF CHARGER DO I NEED

    Reply  •  Rated article 5  •  May 7, 2020 at 11:38 am
    • BatteryStuff Tech
      MF stands for Maintenance free and doesn't refer to the chemistry of the battery. I would suggest looking further into your battery specification as it will most likely refer to the chemistry elsewhere. The other solution is you can get a charger that works for all three lead acid chemistries assuming you know it is a lead acid battery. If you need further assistance we would suggest reaching out to our tech department.

      Reply  •  Rated article 5  •  May 8, 2020 at 2:31 pm