A: When a lead acid battery is fully charged the electrolyte is sulfuric acid with a freezing point of below -40°C. Check Battery … This means a more accurate reading. If you did notice the warning light on the battery is probably down on charge which is not the fault of the battery. Most maintenance-free (read: replace on death) car batteries tend to last 4 to 7 years. But it's only a year old. 4.1 out of 5 stars 17. Obviously, a 60mA drain over 2 days shouldn't drain a full Volt off the battery. AUTOUTLET Automotive Car Battery Load Tester and Voltmeter 6/8/12/16/24V Battery Voltage Tester and Charging System with Printer & LCD Display for All Batteries Car,RVs, Motorcycles, ATV,Boats. Also, the issue isn't just a run-down battery that the car is having a hard time charging--it's never been run down significantly since new (never left anything on or let it sit for very long, and I drive multi-hour trips fairly regularly). You can check the power with a multimeter to ensure the battery is fully charged. The battery charger just did not want to know so, I borrowed someones car battery and with jump leads connected both batteries together. Set the voltage regulator up to charge the 8 volt & things worked quite well. In the circuit below. When your car battery dies once, it may be tempting to just write it off as a fluke. FREE Shipping on orders over $25 shipped by Amazon. Checked the alternator and it read 14 volts. 12v to 5v Volt Converter, DROK DC Voltage Regulator Board Power Supply Module, DC 6.3-22V 12 Volt to 5 Volt 3A 15W Waterproof Car Volt Step Down Buck Converter. 59. Cite. Typically, a charged battery pack will have 2-3 volts higher on a charger than its rated voltage. Christine A. Smilgius on January 18, 2017: Last year my car has not been driven for 2 months because of hip surgery. Because many RVers like to be able to go without power for extended periods of time, all RVs are usually equipped with deep cycle batteries. A twelve-volt car battery is made up of six cells, each producing 2.1 volts and that are connected in series from positive to negative. Its power drops from 100% to 25%. Q: Can a car battery freeze when it gets too cold? Follow answered May 5 '11 at 16:48. supercat supercat. These types of batteries should never be taken down past 50% of their capacity. Only 12 left in stock - order soon. In a car 12V is dead, a “12V” lead-acid battery should be above 12.5V at rest. Typical car-load of 8-volt golf cart batteries will weigh 1000-1200 pounds, rather than 1200-1600 pounds if you use the same overall voltage of 6-volt batteries. If the battery stays above 11.8 volts it will generally still start the vehicle. Then battery was reading 12 volts . Essentially, the battery's lifespan will become reduced over time by being used, such as due to charge cycles or powering anything. To charge a battery, a charger or your car's alternator needs to raise the voltage across the battery posts. Headlamps that were rated at 6 volt only would burn out more often, the other bulbs were rated at 6-8 volts and rarely failed. We add 2 diodes (0.7V + 0.7V). I've always thought when boating that you never let your 12 volt battery drop under around 11 volts, so this very passive stance has confused me a bit. I was faced with a battery having only 1.8 volts after my car was not used for 5 weeks. At 12.4 volts, a car battery is 75% charged while at 12.2 volts its 50% charged. Any advice would be great thanks. My son used battery cables and got it started. Now, just because a battery pack displays 48 volts or more after a full charge does not mean they’re good. It will increases the output by +0.7V for every diode used. If battery charge warning light was not on light the last time you drove your vehicle the alternator is working correctly. A good, healthy car battery should have no fewer than 12.6 volts. Consider your car battery charged at 12.4 volts or higher and discharged at 12.39 volts or less. It turns over, but won't spin fast enough to catch. Running cars have alternator voltage regulators set between 13.5 and 16V. Your car battery is designed to store electrical power which is used to start the engine when the key is turned to the crank position. This car battery test determines how fully charged your battery is. Fifteen 8v batteries weigh less than 20 6v golf cart batteries, overall. I checked the voltage at idle, and it's 13.8 volts. 8 volt battery will need to maintain 7 volts for 15 seconds at the advertised 20hr Ah rating, and then the ; 12 volt battery will need to maintain 11 volts for 15 seconds at the advertised 20hr Ah rating. 10.5V is a destroyed battery for a normal (not deep-cycle) automotive battery. Car battery. Share. 4.6 out of 5 stars 508. If your battery is old or weak, it will not hold a full charge well. This test is done twelve hours after shutting off your car, so that any surface charge can dissipate. volts and hey, he had no problems with it. Reasons For Battery Failure. 8 volt batteries were common crutches on worn 6 volt Olds V8's. 3. Car batteries were built to provide short bursts of power and then to be charged to full capacity right afterward. In general, if the battery is showing between 12 and 12.4 volts, it’s safe to recharge it using your vehicle’s alternator. Once you start the car, the alternator generates additional electric power to recharge the battery. A search on the web brought me here but I am from the KISS school. Although perhaps it is a bad battery that cannot be fully charged... emsvitil. It uses its charge to power the vehicle systems while it's parked and to turn over the engine when you want to start it. Fifth, it prevents your equipment from running the car's battery down so the car can't be started. Car batteries that may have been damaged during extremely hot weather can show signs of failure and batteries can actually freeze if the temperatures drop low enough! It would not start. BATTERY TAPS & 8-VOLT BATTERIES: The problem with ‘tapping’ into 2 batteries for a 12-volt power supply is twofold: PROBLEM #1, 48-VOLT SYSTEMS: In Club Car & Yamaha 48-volt systems there is no place to tap into 12-volts. Because of the way lead-acid batteries discharge, it's important that you test the battery after it's been sitting for a period of time to get what's called the 'resting voltage'. The typical car battery, driven every day, properly charged, and never deep-cycled, could last upwards of 7 years, but that’s a best-case scenario. If your car consistently won't start, it’s possible that the battery is worn out. Then your mechanic may either use a multimeter/voltmeter, or a dedicated battery tester. In one configuration it cuts off the car's battery when the voltage gets below 13.1 volts, then switches over to the external battery, in other words, it switches over to the auxiliary battery when the engine is shut off and the alternator stops. When we add a chain of a diode such as 1N4148, in series at between the common pin of IC1 and Ground. My mechanic says he tested the battery and it's bad. The test is done with the engine off. Lester Charge/Discharge Tester . Each cell is made up of an element containing positive plates that are all connected together and negative plates, which are also all connected together. $26.99 $ 26. However, when I turn on the headlights and the blower motor, (not engaging the starter), the voltage on the battery plummeted to 8-9V within 10-15 seconds of doing so. Ideally, the best way to know if your battery is good is to charge it out of the application, and come back 12hrs later to see what the voltage of the battery drop down to. If you measure battery voltage and it is anywhere over 14.2 volts and less than 14.8 volts with the car running at slow cruising engine RPM speeds and maximum loads on, you already have a bigger alternator than you need. Many devices with a 12-volt nominal input would be perfectly happy if driven directly by a car battery that was not connected a charger (or worse, something like a starter motor--starting a car can cause its +12 rail to swing up and down by dozens of volts). Marine Batteries. Another guy insisted his car battery had at some point been as low as 2 (!) 02-26-2011, 08:48 PM. We can test this by using a Volt Meter. I charged the battery up again today to 12.3V. Get it as soon as Wed, Apr 21. Get it as soon as Thu, Apr 8. 1-16 of over 1,000 results for "8 volt car battery" Price and other details may vary based on size and color . Age of Battery: If the date code on the battery indicates it is fairly old, the failure may be due to natural causes. Loose battery cables make it difficult to start the engine too, as they cannot transfer the electrical current efficiently. 99. For example, a 48 volt system will have 51 to 52 volts after a full charge. After the battery reaches its full charge during the absorption phase of charging the charging voltage drops down to around 12.8 to 13.2 volts in order to reduce gassing and prolong the life of the battery. When a car drops, for instance, from 12.6 to 12.0, there will be 75% difference. Improve this answer. Car batteries tend to last for several years, but lifespan depends on how they are used. Because the battery was 8 years old, I decided to buy a new one. 8. If your battery is old or damaged or isn’t reading 12.6 volts when fully charged, you may want to replace it before moving on. However, we modify a 7805 to the output of 6 volts in easily. Not sure what is the problem. For example: Powering a 120 volt system means using 20 six volt batteries, or 15 eight volt batteries. Read more about recharging below. The car battery is rechargeable. If your car battery is above 12 volts, go for a drive. Many car batteries are 12.6 volts. Remove the negative battery cable from the negative battery terminal. Is there data available to quantify a loss in lead-acid battery quality from low-voltage events? The step down 12 volts to 6 volts DC converter using 7805 and diodes. $12.59 $ 12. Old battery. Today, most cars have a single maintenance-free 12-volt acid battery (in the photo). As the battery discharges the voltage will sag down to 10 volts or lower. If voltage is over 14.2 under maximum loads when at cruising RPM, buying a bigger alternator or a new alternator is a waste of time and money. Car batteries can die for a huge range of different reasons, and there’s always the chance that whatever went wrong won’t go wrong again. While some battery may accept a full charge that doesn't mean the battery will retain that charge. How many volts should a car battery have?