generic 6v 4.5Ah lead acid battery capacity test

I was replacing the lead acid battery of some rechargeable lamps at home.

I had previously posted the result of the Omni SRB-6V4 6v 4Ah lead acid battery testing.

But actually, I had first bought a cheaper non-genuine "Panasonic 6v4.5Ah" lead acid battery at Php180 (around US$3.50).

I know it's non-genuine since the label appears to be stickered on the battery, and the price is cheap (I'd like to test how it performs).

The said battery weighs 558 grams on a digital scale (compare: the Omni SRB-6V4 weighs 672 grams).

After charging for around 6+ hours (not sure if "full" but I think should be near-full), I tested draining it @ 0.67A (this is the 5-hour discharge rate as per specs of other similar batteries) with EBD-USB+:

The result is far too low from the 4.5Ah rated. Also, I drained to 4.20v which is likely too low (I'm not sure what's the cut-off voltage, but maybe 5.2v or 5.0v?), anyway it just reads nearly 1200mAh. Checking the logged data, at around 5.20v, the capacity reading was around 1100mAh.

(compare: the Omni @ 5.20v gave around 3700mAh discharged capacity).

So, even if it's 1/2 the price of the other good one, the capacity is only 1/3..

Not a good battery.

[edit, just noticed graph was missing first part... now re-posting with mAh as the X-axis)

I tried charging after it was drained, using the YASO-0602 6v2A Pb charger (same charger mentioned in my Omni battery)

It filled up very quickly in one hour, because it has a low capacity.

(Not sure if this charging graph is “good Pb charging” graph)

reading the graph:
charging started at around 7.0v @ 1.2A, current slowly decreases until voltage reaches 7.3v (current down to around 0.4A by this time) [charger red indicator = charging status]

once it reaches 7.3v, charge current drops to around 0.2A (float charge: charger indicator green now)

only around 960mAh charged capacity when charger turned to float charging

Pics of the “Panasonic” 6v 4.5Ah lead-acid battery
(actually I’m guessing that it’s non-genuine, given that it seems to be “sticked-on” label, plus the low performance)

Seems you got a Panascanic battery. ;-)

Regarding the potential deep cycling damage these batteries may take when deep cycled, may I suggest you giving this crappy battery (or whatever other at your will) a few more discharge cycles in order to evaluate the discharge performance progression?


Cheers ^:)

its a fake.
all genuine panasonic agm i have seen are printed not stickered.
but the bigger issue is how it was(not) maintained before sale.
float it at 7.5v for a few hours and see if it gains capacity.
it may be sulphated.this happens when they are in stock a long time and self discharge.
more likely its just poor quality.
all real panasonic agm i have bought new exceeded the marked capacity.