how to use this battery charger- BRADEX

[benny123]

I inherited a car battery charger - BRADEX 8AMP. No instruction
manuals.
It has a switch to select LOW and HIGH charge current. There's also a
current meter. That's about it. No other indications.
I'd like to try using it to charge my car battery which I suspect is
flat. So how do I use it? How do I know when to stop charging?
My car battery is a Century... 65AH printed on it.

Thanks for any guidance,
Ben

[j]

65AH mean 65amp-hours = (in theory) the current it will delivery times the
period of time it will deliver that current for. i.e. it should deliver 5
amps for 13 hours.

You can also use this as a charging guide. If you charge the battery at 8
amps (charger rating) from flat, it will take (65 / 8) hours, which is
about 8 hours.

If you were charging a smaller battery, you would select the lower current
setting. This is because batteries charge best when charged slowly.
Charging them too quickly can cause over heating and/or bending of the
plates.

When you first start charging the battery the current meter will show a high
reading. As the battery charges the current will drop. It never goes to
zero. Dissconnect the charger when the current stops dropping.

Also remember, + lead on the charger goes to + on battery, else you will
get a big spark and/or lots of smoke!
--
James

website: www.RacingDrives.com

Post by benny123
I inherited a car battery charger - BRADEX 8AMP. No instruction
manuals.
It has a switch to select LOW and HIGH charge current. There's also a
current meter. That's about it. No other indications.
I'd like to try using it to charge my car battery which I suspect is
flat. So how do I use it? How do I know when to stop charging?
My car battery is a Century... 65AH printed on it.
Thanks for any guidance,
Ben

[benny123]

Hi,
Thanks for your reply.
I tried it.... the meter is hovering at 2 amps... does that mean the
battery is not totally flat?

[Bill]

Post by benny123
Hi,
Thanks for your reply.
I tried it.... the meter is hovering at 2 amps... does that mean the
battery is not totally flat?

In which range on the charger? high or low?

[benny123]

Post by Bill
In which range on the charger? high or low?

high... the meter just reads ~2 amps. if i switch to low, the reading
is less.

I charged it for 3 hours last night, then another 3 hours this
morning... same reading as always. and the battery doesn't become warm
or anything.

Now I wonder if it could be due to the mains supply... the charger
says to input 250V... but here it's around 220-240V.

[e***@gmail.com]

The charger will show a very low rate on the meter. When it stop dropping for a couple of hours that is when you know the battery is fully charged. I have a 20 year old Bradex 4amp charger which I use on the low setting. It still charges the big battery on a 2,2 crd Pt Cruiser very well but takes time. As I am now retired that is not a problem

[Arlen Holder]

Post by e***@gmail.com
The charger will show a very low rate on the meter.
When it stop dropping for a couple of hours that is when you know the battery is fully charged.
I have a 20 year old Bradex 4amp charger which I use on the low setting.

I too have a steel lunchbox-style battery charger 50 years old, which pegs
at 6amps on the dial.

On a dead battery, it will slowly drop from about 5 amps to less than about
an amp, over time.

Then it will stay there below an amp, forever.

[Xeno]

Post by e***@gmail.com
The charger will show a very low rate on the meter. When it stop dropping for a couple of hours that is when you know the battery is fully charged. I have a 20 year old Bradex 4amp charger which I use on the low setting. It still charges the big battery on a 2,2 crd Pt Cruiser very well but takes time. As I am now retired that is not a problem

Batteries should be charged at 10% the battery's amp hour rate. For a 40
AH battery, then 4 amps is perfect. By doing a slow recharge, you are
not going to be gassing the battery much, if at all, and you reduce risk
of internal damage (buckled plates) to the battery. You also
reduce/break down sulphation in the plates.

[j]

Don't worry about the actual number on the meter. Battery is charged when
the current stops decreasing.

If the current stays at two amps and the battery does not retain the charge,
it's a fair sign the battery is past best. i.e. buy a new own.
--
James Caldwell

e-Mail: ***@RacingDrives.com
website: www.RacingDrives.com

Post by benny123
Hi,
Thanks for your reply.
I tried it.... the meter is hovering at 2 amps... does that mean the
battery is not totally flat?