Charging a battery.

Mach Two

What is the best way to charge a battery. It is only a small battery 12v 7ah but I would still like to know the correct way to go about charging it. I have a battery charger with a switch on it. 6v and 12v. I have it switched to the 12v setting and would like to know how long to leave it charging.

biko

Depends, is the charger designed for trickle charging?
There is no need to keep charging battery when full.

Do you know how to check if a battery is fully charged?

Del2005

Mach Two wrote: »

What is the best way to charge a battery. It is only a small battery 12v 7ah but I would still like to know the correct way to go about charging it. I have a battery charger with a switch on it. 6v and 12v. I have it switched to the 12v setting and would like to know how long to leave it charging.

It depends on what the battery is made from and if your charger is suitable for it. A lead acid battery will charge easy enough just leave overnight and it should be full. Any other type and you'll need to make sure that your charger is compatible and if it is most will display when charged.

There's little risk of leaving a battery on charge permanently once it's kept in a well ventilated location, vented hydrogen gas. Loads of 2nd cars and bikes are on charge all the time due to low usage

CJhaughey

How many amps does the charger put out?
A small battery like a 7ah should be charged at 1/10th of its capacity, 0.7 amps in your case, big amperages will kill a small battery quickly.

greasepalm

i might ask how old is battery= coming near end of life if needing charging all the time?

Mach Two

It is a valve regulated lead acid battery. I presume just an ordinary lead battery. The charger is a 6 amp battery charger with a gauge telling you how much it is charging I presume. It is not a trickle charger and the battery is new. I just wanted to bring it up to max capacity. I can only presume that it has lost considerable power from being left on the shelf.

How do I check to see if battery is fully charged.

greasepalm

in the garage we have the two pronged tester but for car batteries,motor factors should have an electronic device to tell how good charged battery is.

CJhaughey

Mach Two wrote: »

It is a valve regulated lead acid battery. I presume just an ordinary lead battery. The charger is a 6 amp battery charger with a gauge telling you how much it is charging I presume. It is not a trickle charger and the battery is new. I just wanted to bring it up to max capacity. I can only presume that it has lost considerable power from being left on the shelf.

How do I check to see if battery is fully charged.

First thing to do is get hold of a Multimeter, this will give you the voltage but not the capacity.
Test the voltage and see what the battery is producing at rest, it should be around 12.7v or if it has been sitting for a long time maybe 12.6 which is 90%
The charger you have is too powerful for a small battery like that, it will damage it due to too many amps being put through a small plate area.
You need to get a small chargeror one that is designed for motorcycle batteries.
There are many types available that will automatically charge and hold a battery at full charge.
But a cheap trickle charger will work as well. Ideally 0.5 Ah is what you want to be able to safely charge the battery without damage.

Mach Two

The battery only cost 25 euro. Argos has a trickle charger that gives out 1.5A . It costs 26 euro. Over what kind of period would my 6 amp charger damage the battery and how long would the 1.5 amp charger take to charge it. Streetwise 12v trickle car battery charger is the name of the charger.

CJhaughey

You want a charger like this one I don't know how long it will take to charge the battery it depends on the state of charge the battery is in.
If you left it overnight I would think a 7ah battery would be pretty well charged by morning.
6amps going into a 7ah battery will likely damage it in an Hour or two I would think, the plates are small and thin in a battery that size and 6amps is a lot of current when you should be using 10% of that figure.

Mach Two

Thanks CJ that would appear to be the business. And not very expensive which is a bonus.

Del2005

Mach Two wrote: »

The battery only cost 25 euro. Argos has a trickle charger that gives out 1.5A . It costs 26 euro. Over what kind of period would my 6 amp charger damage the battery and how long would the 1.5 amp charger take to charge it. Streetwise 12v trickle car battery charger is the name of the charger.

What is the battery going into? If its a vehicle stick it in and see if it'll start it. If it does leave it running, or even better take it for a spin, for about half an hour and it'll be fully charged. If it's for something that's not used often or doesn't have the ability to recharge the battery then you'll need a suitable trickle charger.

Mach Two

It has not got the ability to charge itself. I ordered the trickle charger that was suggested above. Many thanks to everyone.