charging deep cycle

[phoenixgold2100]

Re: charging deep cycle

I have been charging this battery for a 3.5 hours now and it is at 13.46 volts. while hooked to the charger the charger I am using is a motomaster 11-1568-8 manual charger with a meter on the front.

The needle started around the 100 and has moved to the 4? Should it go all the way to the 0 when it's done and the volts at the battery be 14?

 

[phoenixgold2100]

Re: charging deep cycle

Ok now my battery is at 14.5 volts on the charger and 13.26 off the charger.. the needle is now closer to the 0 would this mean just about charged?

 

[UncleWillie]

Re: charging deep cycle

Houston, We have liftoff!!!

Now were charging.
At 14.5 and near 0 amps you are about full.
Note that the current is extremely low indicating that the battery will take no more.
And that even though the charger is set to the 10 amp setting it is delivering less than 2 amps.
Lesson; The Current is controlled by the Battery, not by the charger.
A 100 amp charger would charge the battery no faster.

This also means that leaving it charge for a few more hours will do no harm.
Small Current = Small Power = Small Effect.

One down, Two to go!

 

[phoenixgold2100]

Re: charging deep cycle

Great info.

Should I let it charge right down to the 0 then and leave it a bit longer or yank it right when it goes on 0? I pulled it off around the 0 and put it on the other battery.

The charged battery volts were 13.66 for a bit and I just checked it and it's now at 12.99.

Should this be going back down to 12.7ish?

 

[UncleWillie]

Re: charging deep cycle

The battery that came off the charger will settle back to ~12.6 in a few hours. Normal.

Leaving it on the charger with near zero amps on the meter is essentially just leaving it in Trickle/Maintenance mode.
It is the same condition the battery in an auto will see on a long road trip. Once it is charged it will take no more.
It will use a small amount of water if it stays above 14 volts for a long period.
It will take many Days/Weeks before it becomes an issue.
Charging it overnight or up to 24 hours is not overly excessive.
Just don't hook up a manual charger in the fall end come back in the spring!

A smart maintainer only charges for about 1 second every couple of minutes.
You can leave one of them attached for years.

 

[phoenixgold2100]

Re: charging deep cycle

I am going to look around for an onboard charger for my boat but for now this charger will do. Again thanks for the info!! I didn't want to ruin two brand new batteries....Well not twice anyway. I charged the old ones with the old charger on 2 amp over night and just assumed they were charged. Killed em!

Thanks willie

 

[slackeribew]

Re: charging deep cycle

Just put them on trickle all night you'll be fine and ready to go.

 

[jhebert]

Re: charging deep cycle

A "12-Volt" battery consists of six lead-acid cells. The full-charge voltage of a cell is 2.15-Volts. A fully charged battery will have a terminal voltage of 12.9-Volts. This varies with temperature.

In order to cause current to flow into the battery from a charger, the charger must have an output voltage greater than the battery voltage. This means most chargers have output voltages greater than 12.9-Volts, and most are around 14.4-Volts. The amount of current that will flow into the battery during charging is determined by the difference in voltage between the battery and the charger, the internal resistance of the battery (determined by its construction and present condition), and the current available from the charger.

The amount of electrical energy stored in a battery is determined by its capacity (from its construction and condition), and is measured in Ampere-hours. If a battery can store 100-Ampere-hours, and it has been completely discharged, it will take more than 100-Ampere-hours of charging current to completely recharge the battery, as some of the energy is lost to heat and other chemical reactions.