General

Although there are many different types of batteries most go through at least two phases. 1 a main charge and 2 a maintenance charge.

In the case of lead acid batteries there is commonly a three phase charge with the odd extra option.

The first stage is Bulk followed by Absorption and then Float

Other options are Equalisation and Maintenance

Rolls provides a table which is consistent with the average Lead/Acid generic battery that is infrequently used for a backup. Though precautions should be made for stratification and other capacity limiters
rolls_charge_rates

The one specifically for the Series 4000 that undergoes regular loading is much higher. This is the table I base my charging parameters on.

rolls_charge_rates_4000

When using automatic temperature compensation Rolls recommends a 5mv adjustment for every degree Celsius from 25 per cell. That's 30mv for a 12v battery
For a six cell battery series 4000 battery that's in regular use the recommended charge voltage is 15v So @ 15 degrees Celsius that's 15 + 0.3v. This is for battery temperature not room or ambient temp.

  • Absorption Time

    The most important part of the charge cycle is the absorption charge. Since the bulk charge only recharges the battery bank to an 70-80% level, the absorption charge completes the charging cycle. If the absorption charge is not completed fully a part of…More »

  • Anomalies

    Drop in voltage with constant current The usual process is for the voltage to rise with a constant current hence the idea that when a battery is highly or fully charged the voltage is regulated. Feb 7th But I have found that although the voltage is…More »

  • Battery Power & Charging

    An obvious thought is that a larger battery requires a larger charge. First however it is important to note that apart from common usage applied to AA and AAA batteries, for example, the word means a collection of units working together, as in a battery…More »

  • Battery Resistance

    For lead Acid Batteries There are two processes where the battery resistance will change. a) The normal operation of charging a battery will increase it's resistance, whilst removing sulfation, and the resistance will drop as sulfation occurs. This…More »

  • Bulk Charging

    Although there are limits to what voltage can be placed across a battery to charge it is largely governed by the current that flows through the plates. Too much and they will buckle, melt or even explode. The first consideration in a Lead Acid battery…More »

  • Deep Discharge

    From sciencedirect.com Irreversible Changes of Active Material Caused by Deep Discharge Deep discharge of batteries often leads to mechanical stresses in the plates, which leads to shedding, poor conductivity, and a diminished lifetime of the system.…More »

  • Electrolyte

  • Equalisation

    The main purpose of equalisation is to balance cells that may have developed different capacities which limits the battery's capacity and encourages sulfation. However equalisation or more properly, charging at high levels, can breakdown sulfation. See…More »

  • Float or End of Charge

    From: http://rollsbattery.com/wp-content/uploads/2018/01/RollsBatteryManual.pdf Float When the Absorption charge is completed, the batteries require a certain amount of voltage to maintain a full charge when no load is applied. This Float voltage…More »

  • Hydrometer: Durite 472

    Yesterday I spoke to Les at Durite about my concerns and today 29th May spoke to Mellisa who is sending an email to Les with directions to this page. a) there is difficulty in viewing the thermometer liquid, being red doesn't help as that is also the…More »

  • Hydrometers

    Update: May 28th 2020 Received the Durite 472. It's larger than I thought but usuable. The liquid in the thermometer is red as is the surround so it's difficult to read the temp.Spoke to a guy at tech 01255 555200 for over half an hour ~ details should…More »

  • Stratification

    To be explained in detailMore »

  • Sulfation

  • Temperature whilst Charging

    Chemical reaction is slow at lower temperatures and so a higher voltage will be required to charge. See first post under charging: http://unveiled.info/index.php/solect/charging/More »

Comments on this chapter

Comment from:

IUI Charging This is a recently developed charging profile used for fast charging standard flooded lead acid batteries from particular manufacturers. It is not suitable for all lead acid batteries. Initially the battery is charged at a constant (I) rate until the cell voltage reaches a preset value - normally a voltage near to that at which gassing occurs. This first part of the charging cycle is known as the bulk charge phase. When the preset voltage has been reached, the charger switches into the constant voltage (U) phase and the current drawn by the battery will gradually drop until it reaches another preset level. This second part of the cycle completes the normal charging of the battery at a slowly diminishing rate. Finally the charger switches again into the constant current mode (I) and the voltage continues to rise up to a new higher preset limit when the charger is switched off. This last phase is used to equalise the charge on the individual cells in the battery to maximise battery life. http://www.mpoweruk.com/chargers.htm

17/05/18 @ 05:23 pm

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