- Jun 25, 2013
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Do leisure batteries deteriorate /still hold charge ?over time even if mh not used even if charged at home ?
Leisure batteries
- Thread starter The general
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- Jun 25, 2013
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- Old wild camper in transit
Just asked google yes they can had mine for 5yrs so looks like they are goosed
AGMs? They seem to be the most vulnerable to ageing, compared to most any other popular battery format.
Lithium generally, have a longer lifespan, up to twice that of the current battery's you have fitted.
Mike.
The usual reason that batteries deteriorate is that they may be left partly charged for several weeks. When a battery discharges, the lead and lead oxide of the plates inside the battery turn into lead sulfate. When it is recharged, the lead sulfate turns back into lead and lead oxide. This is a chemical process, and is crucial to the battery operation.
If the battery is left for a long time in the partly charged state, the lead sulfate goo that forms as above starts to crystallise, and can't be turned back into lead/lead oxide plate materials during recharging. That means the battery gradually loses capacity.
The standard way to avoid this deterioration is to fully charge the battery to 100% every month or so, to clear out any lead sulfate and prevent it crystallising. A 3-stage intelligent charger set to the correct profile for the battery type will do that. It may take several hours to do complete the task.
An intelligent charger has three stages: bulk, absorption and float. In the bulk stage, the full output current (amps) goes into the battery, and the voltage gradually rises. When the voltage reaches the absorption voltage, it switches over to the absorption stage.
In the absorption stage, the voltage stays fixed at the absorption voltage, and the current (amps) gradually falls as the final charging is completed. The absorption stage may be extended for some types of battery (Gel, AGM) that require a 'recombination' stage. That's when any gases produced during charging (hydrogen and oxygen) recombine together to form water which returns to the acid electrolyte. When the amps falls to a predefined value and the required time has elapsed, the charger decides the battery is fully charged, and switches to the float stage.
In the float stage, the charger applies a reduced voltage, usually about 13.5V, which is just enough to compensate for the small internal self-discharge of the battery. It can be left in the float stage indefinitely without overcharging or deterioration.
The exact voltage during the absorption stage is important. Different battery types require slightly different voltages. Some AGMs require about 14.7V, while Gels and standard 'flooded' batteries require about 14.4V. AGMs set to a 'Gel' charging profile is a common reason for AGMs to deteriorate faster than expected.
If the battery is left for a long time in the partly charged state, the lead sulfate goo that forms as above starts to crystallise, and can't be turned back into lead/lead oxide plate materials during recharging. That means the battery gradually loses capacity.
The standard way to avoid this deterioration is to fully charge the battery to 100% every month or so, to clear out any lead sulfate and prevent it crystallising. A 3-stage intelligent charger set to the correct profile for the battery type will do that. It may take several hours to do complete the task.
An intelligent charger has three stages: bulk, absorption and float. In the bulk stage, the full output current (amps) goes into the battery, and the voltage gradually rises. When the voltage reaches the absorption voltage, it switches over to the absorption stage.
In the absorption stage, the voltage stays fixed at the absorption voltage, and the current (amps) gradually falls as the final charging is completed. The absorption stage may be extended for some types of battery (Gel, AGM) that require a 'recombination' stage. That's when any gases produced during charging (hydrogen and oxygen) recombine together to form water which returns to the acid electrolyte. When the amps falls to a predefined value and the required time has elapsed, the charger decides the battery is fully charged, and switches to the float stage.
In the float stage, the charger applies a reduced voltage, usually about 13.5V, which is just enough to compensate for the small internal self-discharge of the battery. It can be left in the float stage indefinitely without overcharging or deterioration.
The exact voltage during the absorption stage is important. Different battery types require slightly different voltages. Some AGMs require about 14.7V, while Gels and standard 'flooded' batteries require about 14.4V. AGMs set to a 'Gel' charging profile is a common reason for AGMs to deteriorate faster than expected.
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