Battery Charging Setting for Deep Cycle?

[MCTFisher9120]

Bought a new deep cycle today. 120min capacity and 60something cranking power. Brand new.

 

I have a older Motor Master charger that I've used on my Marine/Starting battery and I am kinda guessing I set my charger right for the last year haha. Here are the setting...try to imagine this

 

Normal/Deep Cycle(im assuming dc for the dc battery and normal for the starting)

 

Then beside that is a title called A/V Selector

Under that it says 70 A Start/12 A/2 A/12 A

Under the 12/2 option it says 12V Auto. Under the 2nd 12 A option it says 6V Manual.

 

I always charged under Normal/12A(12V Auto) Hope I get some help

[Terry]

yeah that should be the right setting

it will charge at 12amps till it hits 85% full then drop to 2 amps

[Fishnwire]

The 70 amp start feature is for starting a car with a dead battery. You don't want that, obviously.

 

There's no point charging a 12 volt battery with a 6 volt source...regardless of the amps a battery can never charge to a voltage level higher than the source voltage...so forget about the 6 volt setting.

 

If you're not in rush, it's better to charge a battery slowly, than rapidly. Use the two amp setting when you can. Make sure the auto feature works right, and that the charger shuts off when the battery is fully charged. Otherwise you can cook the battery.

[Terry]

it is not best to slow charge them

 

 

Battery charging takes place in 3 basic stages: Bulk, Absorption, and Float.

Bulk Charge - The first stage of 3-stage battery charging. Current is sent to batteries at the maximum safe rate they will accept until voltage rises to near (80-90%) full charge level. Voltages at this stage typically range from 10.5 volts to 15 volts. There is no "correct" voltage for bulk charging, but there may be limits on the maximum current that the battery and/or wiring can take.

Absorption Charge: The 2nd stage of 3-stage battery charging. Voltage remains constant and current gradually tapers off as internal resistance increases during charging. It is during this stage that the charger puts out maximum voltage. Voltages at this stage are typically around 14.2 to 15.5 volts.

Float Charge: The 3rd stage of 3-stage battery charging. After batteries reach full charge, charging voltage is reduced to a lower level (typically 12.8 to 13.2) to reduce gassing and prolong battery life. This is often referred to as a maintenance or trickle charge, since it's main purpose is to keep an already charged battery from discharging. PWM, or "pulse width modulation" accomplishes the same thing. In PWM, the controller or charger senses tiny voltage drops in the battery and sends very short charging cycles (pulses) to the battery. This may occur several hundred times per minute. It is called "pulse width" because the width of the pulses may vary from a few microseconds to several seconds. Note that for long term float service, such as backup power systems that are seldom discharged, the float voltage should be around 13.02 to 13.20 volts.

 

 

[AzuluSpookd]

Did you just say "Pulse Width Modulation"???

 

I'm impressed Mr. Terry

[Fishnwire]

The amount of voltage doesn't really determine how fast the battery charges...the amount of amps does. While electronic chargers do modulate their voltage depending on the relative voltage (internal resistance) of the battery being charged, the higher the amp setting, the quicker the battery will charge. At the same time, the quicker a battery is charged, the more heat that is created. You want to avoid that heat, whenever possible.

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Take two identical batteries and two identical chargers. Always use the lowest amp setting on one charger and battery and the highest amp setting for the other charger and battery. Assuming both batteries are discharged in a simular fashion, you can be sure the battery that was always charged slower will have a longer life.

Edited June 11, 2010 by Fishnwire