I understand that AC Delco encodes the month of manufacturing a car battery using two digits and encodes the year by one digit. The battery I just purchased, for example, is labeled P124R, which, IIUC, means that it was made in December 2014. I'm puzzled by this ambiguity regarding the decade of manufacture. How does a buyer rule out he's dealing with an exceptionally unscrupulous retailer who put on the market 10+ year-old stock? Just as importantly, how can a manufacturer of AC Delco's renown make the date this ambiguous? Is it, for instance, the case that a battery that has been sitting on a shelf for 11 years will be so unusable that it could not possibly be sold as a one year old battery? NOTE: Much of your question seems to be a rant, so I will answer the last part, which seems to have gone unanswered to this point. According to the Battery University, a typical lead acid battery will lose about 5% of its charge every month (whether this means 5% of of the total charge when completely full - ie: 5%, 10%, 15%, etc, or 5% of the remaining charge - ie: 5% of 100%, 5% of 95%, 5% of 90.25%, etc, is unclear).

This means if a battery sits on the shelf too long, it will need recharged after a period of time to be fully operable in a vehicle.hard start for ac unit That is for a battery which is stored wet (with acid in the cells). proper window unit ac installationA dry battery (one without an electrolyte) will maintain on the shelf indefinitely. home ac unit not runningOnce the electrolyte is placed in the cells, the process begins. There is another factor which will make a battery go bad. According to the same website: With usage and age, however, the flooded lead acid builds up sludge in the sediment trap, which causes a soft short when this semi-conductive substance reaches the plates. This can cause issues when the battery gets old.

I assume it happens at a slower rate while on the shelf, but will still happen over time as it becomes aged. What this means is, a battery with acid in the cells can only sit on the shelf for so long before it must be recycled or it will not work right. Have no fear, though, lead from batteries is one of the most recycled things we humans pull out of the ground. A battery which has sat on the shelf for too long, while it may not provide you good usage, will still be able to be exchanged for a new one under the normal battery warranty programs. I'm sure batteries are sold beyond their expiration dates, but they are also easily replaced. AC Delco's website addresses this: How do I read the warranty date code on my battery? The warranty date code is located on the top label of the battery. The first character is either a P or S. The next two digits determine the month, the third digit is year and the fourth digit indicates the manufacturing plant. For example, P 094N means the battery

was made in September 2014. See the answer below for more information about battery life. Either way, the warranty period for your battery starts from the time of purchase. It pays to get a Solar brand battery tester which uses a conductance test to evaluate how many CCA is left in your battery. That way you can decide when it is time to let go of the battery.Browse other questions tagged battery or ask your own question.Thermostats are typically reliable devices, but they can run into problems. The thermostat controls both the heating and cooling systems of homes with central heat and air conditioning, or just the furnace in homes without air. The thermostat detects the temperature of the room and compares it to the desired temperature setting. If the room is too warm or too cold, the thermostat requests heat or air depending on the season. Set the thermostat at least 5 degrees higher or lower than your normal setting, depending on the season. Set it 5 degrees higher than normal during heating season, and 5 degrees lower during cooling season.

Check that the appropriate device comes on. Determine whether another problem might cause the device not to work properly. Check that the thermostat is correctly set to “Heat” or “Cool.” Check that the main circuit breaker for the furnace or air conditioner is in the “On” position. Turn off the power for the furnace and air conditioning systems by switching the appropriate circuit breaker to the “Off” position. Remove the cover to the thermostat. They typically come off with gentle prying by hand. Check the wires, making sure each is attached firmly to its respective mounting screw. Reattach any loose wires and tighten loose mounting screws. Flip the breakers back on and determine whether the device runs by repeating Step 1. If it does not, turn the furnace and air conditioner power back off again at the breaker panel. Study the wires inside the thermostat. Choose the red and white wires if you are having problems with the furnace kicking on, or the red and green wires if you are having issues with the air conditioning system coming on.

Unscrew the two appropriate wires from their terminals. As you loosen the screws, grip the wires with your other hand so they don’t slip behind the wall. Wrap the two wires together, and turn the breaker back on. If the blower comes on -- for furnaces or air conditioning systems -- the thermostat is bad. Things You Will Need Screwdriver References Don Vandervort’s Home Tips: How to Test a ThermostatHVAC for Beginners: Thermostat Replacement, Do It Yourself And Save... Photo Credits Ryan McVay/Photodisc/Getty Images Suggest a CorrectionThe cooler months are creeping in and your air conditioner has outlived another hot, summer season. But how do you know if it will survive next summer’s heat wave? Here are some common indicators that your air conditioning system could be on its last limb.If you find yourself calling for AC repairs yearly, it is most likely time to invest in a new system. Frequent repairs probably means your AC is starting to give out, and it’s much better to get the issue under control before you’re caught in the middle of a sweltering summer with no AC.

This one should seem obvious, but if your AC doesn’t seem to be cooling your home properly, it could be for a number of reasons. Problems such as a compressor failure, a wrong calibrated thermostat or a refrigerant leak are all issues that could cause your AC to run improperly. Once you find out the situation, it could be the case that it’s more cost efficient to purchase a new air conditioner.If you’ve noticed a hike in your HVAC bills it could be a sign that something is wrong. Air conditioner’s that have to work overtime are using much more energy, and it might make sense to invest in a more energy-efficient air conditioner that will decrease your peak season payments.Unusual noises means there is some kind of problem with your AC. High-pitched sounds could be a motor issue, and rattling noises may indicate that a part is loose. Don’t risk it by letting it go. You can call one of our HVAC professionals to inspect it and determine whether the problem is worth repairing or if it’s time to throw in the towel and opt for a new unit.