There are a lot of different opinions about battery charging and we hope this will help clear up any confusion that our customers have. AGM batteries are still technically a lead acid battery and they charge very similar to a wet cell. Regardless of what some rumors portray, AGM batteries are not as sensitive as once believed. They often get confused with Gel Batteries, which are very sensitive to voltage and they need a special charger. Lifeline AGM batteries can also be equalized to regain capacity if need be (instructions for equalizing is listed below). We also offer very personal service if you would like to reach us by telephone should you have any further questions regarding our batteries.
Battery Charging:
Charge 1 with voltage-regulated (constant potential) charger. The following charging voltages are recommended for maximum battery life.
3 Stage Chargers
Bulk
14.2-14.4 volts
Acceptance
14.2-14.4 volts
Float
13.2-13.3 volts
2 Stage Charger
Bulk
14.2-14.4 volts
Float
13.2-13.3 volts
Single Stage Charger
Bulk
14.2-14.4 volts
Once the battery is fully charged, remove it from charger.
Battery Equalizing and Deep Discharge Conditioning
Charge:
Charge with voltage-regulated (Constant voltage) charger.
Charge1 @ 15.5 volts for 8 hours.
¹ Avoid overcharging. All batteries must be adequately vented during charging to avoid accumulations of explosive hydrogen gases. Never install or charge in a sealed container or sealed room.
Equalizing should only be done when the battery is showing symptoms of capacity loss or from inadvertent deep discharges. In the event equalization is necessary, make sure to go through the normal charge cycle. Once the battery is fully charged, begin equalizing.
Note: For 24 volt battery banks, simply take the charge voltages as provided above and multiply by 2.
For maximum battery life, a battery must be recharged to 100% capacity. Recharging less than 100% may result in premature battery failure. Lifeline batteries are not covered under warranty if they are not recharged properly. For more information, please refer to our warranty policy.
For Inverter/Charger applications:
Refer to the Inverter/Charger manual to ensure the correct voltages have been set.
Knowing when to recharge:
For maximum battery life in deep cycle applications, do not discharge the battery bank below 50%. Continually discharging the bank 100% will shorten the battery life. The open circuit voltages listed below approximates the various States of Charge (SOC).
DOD (%)
1 hr. Rate
8 hr. Rate
20 hr. Rate
120 hr. Rate
10
12.23
12.62
12.65
12.79
20
12.16
12.51
12.55
12.69
30
12.07
12.39
12.42
12.55
40
11.96
12.25
12.28
12.40
50
11.83
12.11
12.13
12.22
60
11.70
11.96
11.98
12.08
70
11.55
11.79
11.81
11.90
80
11.38
11.59
11.61
11.70
90
11.15
11.32
11.34
11.43
100
10.50
10.50
10.50
10.50
Please note that these voltages are averages and will vary slightly from battery to battery even
of the same rating. They are, however, a good indicator of state of charge and can be used
when setting low voltage alarms or disconnects for a Lifeline AGM battery. Other battery
types or manufacturers voltage vs. DOD may be substantially different. The data is for newer
batteries with relatively few cycles. An older battery will measure a lower voltage for a given
DOD.
SOC (%) vs. OCV the battery State Of Charge vs battery's Open Circuit Voltage
An easy method to estimate the State of Charge (SOC) of the battery is by measuring its Open
Circuit Voltage (OCV). This measurement should be made after the battery has been at rest for
a minimum of four hours with the battery shut off from its charging source and load. The voltage
is listed as Volts/cell and for a 12V (6 cell) battery at 25°C (77°F).
State of Charge (%)
OCV per cell
OCV per 12V battery
100
2.17 or greater
13.0 or greater
75
2.10
12.6
50
2.03
12.2
25
1.97
11.8
0
1.90 or less
11.4 or less
Multiple Batteries:
If there is more than one battery in the battery bank, the following guidelines should be used:
Always use batteries of identical make, model and with the same manufacturing date.
Make sure the battery cable is not undersized for the battery system.
Make sure the battery cables are connected to the terminals correctly. If unsure, professional assistance is recommended
BD Batteries - A Broomfield-Designers Company
Serving the Local Colorado Community 9-5 Mountain & Emergencies P. 303-800-4725 F. 303-600-9726
Serving the Buffalo and the Great Lakes Communities 9-5 Eastern & Emergencies P. 716-531-4875
Mailing Address: 5023 West 120th Ave. #138, Broomfield, CO 80020
OUR DENVER WAREHOUSE IS MOVING TO A NEW LOCATION AT THIS TIME.
WE WERE SCHEDULED TO REOPEN OUR BRICK AND MORTAR BATTERY WAREHOUSE IN EARLY 2011.
IN THE MEAN TIME OUR WEBSITE AND PHONES OPERATE FINE!
We do thank the public for the outreach of concern, and votes of confidence.
Do call Lorene prior to schedule used battery pickups, new battery dropoffs, etc. by appointment.
The information contain on this deep cycle AGM batteries website is deemed reliable, but not guaranteed. Please verify specific information on marine AGM batteries, rv AGM batteries or auto AGM batteries listed here by calling us direct. We are proud to offer the highest quality AGM batteries and hope you will consider using our deep cycle AGM batteries in the near future!
