# Battery Specification

J

#### Jack// ani

Jan 1, 1970
0
Hi all,

I just took out a dead Panasonic lead acid battery form my UPS and
trying to understand the specifications written on it

Voltage Regulation
Cycle use : 14.5 - 14.9V
Initial current : less than 2.8A
Standby use : 13.6 - 13.8V

TIA

L

#### Lord Garth

Jan 1, 1970
0
Jack// ani said:
Hi all,

I just took out a dead Panasonic lead acid battery form my UPS and
trying to understand the specifications written on it

Voltage Regulation
Cycle use : 14.5 - 14.9V
Initial current : less than 2.8A
Standby use : 13.6 - 13.8V

When you charge the battery, limit the applied voltage to between 14.5 and
14.9 volts DC
and limit the current to no more than 2.8 Amperes. As the battery charges,
the current will fall.
If you wish to 'top off' the battery or trickle charge it, keep the applied
voltage between
13.6 and 13.8 volts DC.

Beware that hydrogen gas forms during charging so vent the area.

J

#### John Fields

Jan 1, 1970
0
Hi all,

I just took out a dead Panasonic lead acid battery form my UPS and
trying to understand the specifications written on it

Voltage Regulation
Cycle use : 14.5 - 14.9V
Initial current : less than 2.8A
Standby use : 13.6 - 13.8V

---

First, go to:

http://www.panasonic.com/industrial/battery/oem/chem/seal/index.html

and then click on:

VRLA Charge Methods

J

#### Jack// ani

Jan 1, 1970
0
Thanks Lord. BTW this battery is sealed form every where( as I can
see), so where does the Hydrogen escapes??

B

#### Byron A Jeff

Jan 1, 1970
0
When you charge the battery, limit the applied voltage to between 14.5 and
14.9 volts DC

That's a bit high for standard gel cels. They usually want 14.4V.
and limit the current to no more than 2.8 Amperes.

Correct. A fully depleated battery can draw a lot of current if you allow
it to.
As the battery charges, the current will fall.

Correct. The basic 3 stage charging algorithm for lead acid batteries are:

1) Bulk charge with highest allowable voltage and current until battery
reaches 2.4V/cell (14.4V for a 12V battery).

2) You then fix the voltage to 14.4V and start watching the current. Continue
in this phase until the current draw drops to C/100, where C is the Amp-Hour
capacity of the batter. So for example with my 33 AHr battery, C/100 would be
330 mA.

3) Then go into float/trickle/top off voltage discussed below.
If you wish to 'top off' the battery or trickle charge it, keep the applied
voltage between 13.6 and 13.8 volts DC.

This voltage is safe indefinitely without venting.

If a sealed lead acid gel cell is venting, then you have big problems.
It's one of the reasons why the specifications listed on the battery are
in place.

BAJ

L

#### Lord Garth

Jan 1, 1970
0
Jack// ani said:
Thanks Lord. BTW this battery is sealed form every where( as I can
see), so where does the Hydrogen escapes??

There is likely a hidden vent that opens if the pressure gets too high.
If that happens, I'd guess the electrolyte would either leak or evaporate.
That's pretty standard for a *sealed* battery.

J

#### Jack// ani

Jan 1, 1970
0
Thaks all. A little doubt left..... is there any relation between
maximum charging current and ampere-hour rating of the battery?

Like maximum charging current above was 40% of the AH rating!

Thanks again

P

#### Peter Bennett

Jan 1, 1970
0
Thaks all. A little doubt left..... is there any relation between
maximum charging current and ampere-hour rating of the battery?

Like maximum charging current above was 40% of the AH rating!

Thanks again

Depends on the battery. For most flooded lead-acid batteries, a
maximum charge rate of 1/5 of the AH rating is generally suggested.
Some gel and AGM batteries can be charged at higher rates.

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