Osaka Tubular bulging — Swollen or Distorted Battery Case

⚠ DANGER — this fault involves lethal voltage. Do not attempt a DIY fix. Call a qualified technician.

What it means: This is a symptom identifier, not an Osaka fault code — Osaka publishes no fault codes for its tubular line, so SolarNevs names these pages after what you can see. The case has visibly swelled outward at the sides. Rolls' troubleshooting section separates two situations. A small amount of bulge on a brand-new battery is normal, because the case relaxes after filling under the weight of the electrolyte, and the thing to check there is that the electrolyte has not dropped below the top of the plates before charging. Excessive bulging on a battery that has been in service is different. Rolls attributes it to the battery having been exposed to temperatures over 51 degrees C, which swells and expands the plates and chassis, states plainly that there is no fix, and says the battery will fail prematurely and require replacement. A visibly deformed case is a scrapped battery, not a serviceable one.

Why does Osaka (Pakistan Accumulators) show bulging?

The Pakistan factor

Heat is the Pakistani version of this fault. Rolls' threshold for permanent case and plate swelling is 51 degrees C, and that is a realistic internal temperature for a battery being charged at an uncompensated voltage in a closed store room in June in Multan or Sukkur — not an exotic laboratory condition. Two local habits make it worse: banks pushed tightly together or hard against a wall to save floor space, so there is no airflow between the cases, and tubular batteries installed in sealed wooden or steel cabinets with no vents. There is also a commercial angle. Osaka publishes no warranty terms on its own product pages, and dealers quote anywhere from 6 to 12 months "as per company policy", so a bulged-case claim is decided entirely by what the dealer wrote on your invoice. Photograph the battery, the serial and the invoice before it leaves your house.

How to fix it

  1. Stop charging and take the bank out of service. Do not watch it for a few days to see what happens.
  2. Do not lift, drag or lever a swollen battery on your own. These units are 55-73 kg, the case integrity is already compromised, and they are full of acid. Rolls warns specifically against lifting a cell by its terminals.
  3. Keep flame, sparks and hot work away and ventilate the room. A distorted case may have a partly blocked or damaged vent path, which is exactly the condition Rolls links to a battery cover cracking or blowing off when hydrogen ignites.
  4. Do not try to relieve the pressure. Never drill, cut, prise or unscrew anything other than the normal vent caps, and do not open even those on a hot battery.
  5. Photograph the battery, its serial number and your invoice before anyone moves it. If it is inside the dealer's warranty window that is your entire case, and it will be argued at the shop that sold it to you.
  6. Call your installer or the dealer to remove and replace it. A swollen tubular battery is a disposal item and must go back through the dealer or a lead-acid recycler, never into household waste.
  7. Do not put the bank back on charge with the swollen unit still in the string. Rolls warns that charging or equalizing a bank containing a failed battery forces the overcharge onto the remaining units and can damage them permanently.
  8. Before the replacement goes in, get the cause fixed — charge settings, room temperature and battery spacing. Rolls recommends 2.5-7.5 cm of clearance on each side for airflow and cooling. A new battery in the same conditions will bulge too.

References