Battery charge query

[Bernie9927]

I have a 12 volt lead acid battery which I use on my golf trolley. On the side of the battery it states :Standby use 13.5 - 13.8 (20 degrees) and cycle use 14.4 - 14.9 (20 degrees).

When in cyclic use and I charge the battery my charger light indicates the battery is fully charged but when I check the voltage it shows a maximum of only 13.7 volts and quickly reduces to about 13.4. Am I right in thinking that the battery should show a voltage of between 14.4 - 14.9 when fully charged.

The battery is relatively new.

Any advice would be most welcome

 

[big-all]

is it a trickle charge or fast charge higher the input voltage quicker it charges

how new is new

 

[Mursal]

The battery will only go to the higher voltage (14v7) when charging. This is due to the charger applying a higher voltage to cause charging. If it went above 14v7 is would be termed as "over charging".

When you disconnect the charger the voltage will drop back to approximately 12 volts. If it dropped back to say, 8 volts then you would need to consider replacement.

 

[Bernie9927]

Many thanks for your replies.

To answer Big All, the manufacturers date is April 2012 and I first used it in June.

In reply to Mursal, I use a trickle charger (3amp) and from your answer I assume the voltage should read approx 14.5/7 when fully charged and not 13.7 which it is currently showing when the charging light indicates it is fully charged. Therefore, do I leave the battery on trickle charge until such time as it reads 14.7 or will this harm the battery ? Your confirmation on this would be appreciated before I do this.

 

[Mursal]

Its fine charging at the lower voltage and because it is a low output charger (trickle) probably will never get to 14v7. But if you but the battery in the car it probably would reach 14v7 while charging. But if it only goes to 13v5 while in the car we say its charging because the charging system has taken the battery voltage up from approximately 12volts, which would be the voltage of a good battery in a car.

The only real way to know a battery is fully charged is to take samples of the acid while charging. Anything else is only a guide. In modern batteries we never touch the battery acid for health and safety reasons.

http://en.wikipedia.org/wiki/Hydrometer

I would leave it on the trickle charger most of the time, especially the days before you are about to go for a round

Hope this helps

 

[Burnerman]

Its fine charging at the lower voltage and because it is a low output charger (trickle) probably will never get to 14v7. But if you but the battery in the car it probably would reach 14v7 while charging. But if it only goes to 13v5 while in the car we say its charging because the charging system has taken the battery voltage up from approximately 12volts, which would be the voltage of a good battery in a car.

The only real way to know a battery is fully charged is to take samples of the acid while charging. Anything else is only a guide. In modern batteries we never touch the battery acid for health and safety reasons.

http://en.wikipedia.org/wiki/Hydrometer

I would leave it on the trickle charger most of the time, especially the days before you are about to go for a round

Hope this helps

Good call Mr M Maybe 3A is a little much for a continuous trickle charge, but that really depends on the battery A/H rating anyway.
John

 

[Peter.N.]

A fully charged battery should read 2.2 v per cell off load which equates to 13.2 volts, at that voltage no current is flowing in or out. To maintain full charge when not in use the charging voltage only needs to be a little higher than this, leave it charging at a much higher voltage for a long period will degrade the battery.

Peter

 

[big-all]

Many thanks for your replies.

To answer Big All, the manufacturers date is April 2012 and I first used it in June.

blimey brand new

as said the input voltage is relivent to the output

 

[Bernie9927]

Many thanks for all four replies. As the trolley manufacturer supplied the charger with the battery, I assume 3amp is sufficient and will continue as before. Thanks all.

Bernie