At its 12V mark, you can see there is a "tipping point" where the voltage goes from relatively constant to plummeting. When a battery is covered in dust and dirt, it can discharge across the grime. As a result of charging or discharging, an uneven mixture of acid and water can arise on the surface of the plates. You can sometimes bring a battery back up by using an old bulk battery charger with no smarts (one that you just switch on, and it starts powering away with no stages or battery detection), but this usually depends on how long the battery has left at this low voltage. I use it to run a 12V 55 lb thrust bow mount trolling motor. When troubleshooting a battery bank set up with a series or parallel circuit and one of the batteries is faulty, it will pull all the other batteries down. Unit 2, 8 Technology Drive, Warana Queensland 4575, Australia. Below are a few common battery problems you can identify by the voltage measurements. iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? No matter where you fit in you'll find that iRV2 is a great community to join. I have a trimetric battery monitor, my microwave pulls 125 amps, my 4 golf cart batteries drop .5 volt while the microwave is on, but returns to the previous voltage or .1 of a volt less when complete. What would be the expected voltage drop if I had two 6 volt golf cart batteries in series with this load? Flooded deep cycle batteries will need to be checked for leaking and damaged battery cases that may have been caused through overcharging or overheating. This means that the battery must NOT be under load and it must NOT be charging. You can sometimes improve a battery in this condition by using a desulfation device, otherwise you’ll have to live with the low capacity or replace the battery. If you find yourself in a situation where you cannot charge the battery, let it sit for approximately one hour before testing. Simply compare the measured voltage with a state of charge table to discover your battery’s estimated charge level. Once you tested your deep cycle battery’s voltage, you can analyse its state of charge. Should I stop at 11.9v under load, or will I be able to go lower than 11.9v if it's under a load? Johnson Control makes the battery, and the Les web site has NO information (big red flag). If you were discharging at 8A and saw 12.55V you would be at a lower SoC than 90%. Batteries must be at 100% voltage before a load test can be applied. Battery voltage drop under load - posted in ATM, Optics and DIY Forum: Hi, I have a CCD in which the cooler draws around 3.6 A (@12 V) for a short time every second (e. g., the camera cooler remains idle for lets say 0.7 s and then draws 3.6 A for 0.3 s). TLI too little information, what are the make and amp hours of the batteries. In a car 12V is dead, a “12V” lead-acid battery should be above 12.5V at rest. If your battery shows a good voltage when it’s fully charged, but quickly drops voltage to 11V or less when using power, this usually means the battery has a faulty cell and needs replacement. This can be caused by excessive vibration such as driving over corrugations without adequate shock absorption for the battery, or a manufacturing fault. At best, it is a marine battery, which is a hybrid between a true deep cycle and a starting battery. So it is pretty much crucial to know how to charge a deep cycle battery properly. Typically, a fully charged deep cycle battery will have a voltage of over 12.8V - 13V. Resting fully charged 12-volt batteries are around 12.8-12.9 volts, and flat dead ones are at 12.0 volts, so 12.4 volts on a resting battery means it's about 50% charged. If you take that DCB down to 6 volts and still need 50 watts of power, you will now force the battery to … Join the #1 RV Forum Today - It's Totally Free! As such, troubleshooting battery problems can begin with a simple inspection. Obviously, it is … For example, if one of your batteries has dropped down to 8V, you may notice that the other batteries within this bank will have low voltage ratings as well. This phenomenon is referred to as a ‘surface charge’, and will need to be removed before the testing begins as it may influence your data. Typically, the voltage of a deep cycle battery with full charge lies between over 12.8V and 13V. The battery is at the rear of the boat and I have a 20 run of #8 wire to it. Maintaining your deep cycle batteries is essential to ensure a maximum life span and to prevent damage. Measure the voltage of each battery. Typically, a fully charged deep cycle battery will have a voltage of over 12.8V - 13V. At 9V it will drop right away under the same loading current. I have noticed that when the inverter is in a state of providing charge that the measured battery voltage is considerably lower than that measured if I switch the inverter off. It is usually considered to be discharging from 100% to some point not lower than 20%, and then charging back up to 100%. At 11V it is almost going straight down. Load voltage (voltage under load or on charge) Open cell voltage. There are six simple steps in testing a deep cycle battery: inspect, recharge, remove surface charge, measure the state-of-charge, load test, and recharge. These are not built for sustained loads and if you are unsure of their pedigree it would be worth your while to have them tested. For example, let's assume you have a system that requires 50 watts of power and are using a deep cycle battery. Troubleshooting deep cycle battery issues is fairly easy to do yourself with the aid of a multimeter, volt meter, or watt meter. When load testing remove all battery cables from their terminals. Any lead acid battery, no matter the nomenclature on the outside, is considered discharged when the battery, under load, reaches 10.5 volts. It's a good place to start, though. So the first battery numbers are believable at 12.77 dropping to 12.19 and rebounding to 12.55. This means that at the 12V point you have essentially used 60% of its capacity. I'm always amused at battery terms like deep cycle, marine, etc., as if those words connote some special property over and above the norm. You are currently viewing our boards as a guest so you have limited access to our community. I'm using a 12v AGM deep cycle battery. On a 400Ah bank this would be a 20A load in order to see this voltage at 90% SoC. If your test shows that this voltage is below 10V, this typically means that the battery has been left in storage for too long without a charge or left with a load running on it that doesn’t have an automatic cut-off. It is suggested to test your battery’s life when it is fully charged. We continue to ship Australia wide, Storage for all applications, chargers, battery boxes, Panels, charge controllers, management systems, Portable fridges, 4WD and caravan, free camping, Reliable power storage for large applications. How to Troubleshoot Deep Cycle Battery Issues, ‘How to Check Your Battery Charge Level and Troubleshoot Issues’. Typically the rating is based on some specific load. For example, if your AGM deep cycle battery rates at 12.30V, it's at a 70% state of charge as shown on our State of Charge graphic. A battery "cycle" is one complete discharge and recharge cycle. When a deep cycle battery is fully discharged (dead flat), it should reveal a reading of approximately 10.5V. It’s different from the car battery and marine battery. Although you can easily troubleshoot any different battery issue yourself, accurately testing a deep cycle battery’s capacity requires a ‘deep discharge’ test. Note: The figures are based on open circuit readings. This charge graphic relates to 12V AGM deep cycle batteries, but can also be used as a general guide for other battery types though keep in mind that there may be slight differences in the voltage rating. For your battery to pass a load test, the multimeter must read between 9.5 to 10.5 volts straight for 30 seconds when the battery is tested. Best of all it's totally FREE! As such, it is recommended to discard any batteries that have reasonably damaged battery cases. Check electrolyte level to make sure plates are covered with water before charging (deep-cycle flooded/wet batteries only). Heavier duty batteries will show less drop. After completed, I turned both 12v LED TVs on, antenna booster, 8 overhead fixtures, 4 bath lights, 7 reading lights, Fantasic Vent on high and ran the furnace. So you have to know the circumstances. This problem won’t occur with AGM deep cycle batteries as they are designed with glass mat technology preventing leakage, even when damaged. These 3 steps will help you determine if your battery is truly bad or getting there. RV Water Filter Battle: It’s Green vs Blue a... 6 Misconceptions About Full-Time RV Living. At 12 vdc, you will require a current draw of just over 4.1 amps to produce that 50 watts. Deep cycle batteries usually have a higher specific gravity close to 1.33 at full charge rather than 1.265 for starting batteries. To remove the surface charge you can simply leave your fully charged deep cycle battery to sit for at least four hours. (Your battery should have a minimum of 12.4 volts.) For a detailed guide on how to test the voltage of your deep cycle battery, you can have a look at our video ‘How to Check Your Battery Charge Level and Troubleshoot Issues’. And How long to charge a deep cycle battery?. Make sure the battery terminals are free of corrosion before testing. 1) With the voltmeter connected to battery, and key and engine off, record a "base" voltage reading. Camping In Utah: Explore the Mountains, Lakes, and... RV Living Makes Dreams Come True For This Couple, 10 Best Washington RV Parks And Campgrounds. Equipment needed: Voltmeter; Carbon pile load tester; A voltage drop test will assess voltage losses at the battery, the alternator and the starter. Generally, a solar panel that provides 1 amp of electrical energy will fully charge a battery in 5 to 8 hours in full sunshine, but this time can be increased as the angle of the sun changes or if it becomes overcast. Faulty cells are difficult and usually impractical to repair, so you’ll need to replace the battery. It runs for less than a minute generally, unless it is fully empty, in which case it will run for a couple of minutes, (but this case will happen less than once a month). Your looking at a chart for starting batteries not deep cycle. General inquiries about batteries | Johnson Controls Inc. Of the batteries substantially recover soon after the heavy load period and otherwise are performing ok, then I don't see a problem. The battery with the lowest rating will be the faulty battery that needs to be replaced. (All lights are LED). No 12-volt battery will remain at over 14 … You can write JC provide size and identifications and they should provide what you have. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more! I understand that deep cycle batteries should not be discharged below 12V (approximately 50% SOC). Sounds normal to me as long as the voltage goes back up when the draw is removed. A small inverter plugged into the 12v cig lighter with its thin wire, will show a big voltage drop under load, but the same inverter with the same load, clamped right to the battery will show much less voltage drop under load. When you decide to test with a voltmeter, we recommend using a digital meter rather than an analogue meter as it will be more accurate in measuring millivolt differences. Although this table is used for 12V AGM deep cycle batteries, it can be seen as a reference source for other types of battery. Below are a few common battery problems you can identify by the voltage measurements. One thing to remember is that they will default to the weaker of the two batteries. I've read that 11.9v is a good minimum voltage to stay above. Also trading under SMART TECH RETAIL GROUP PTY LTD (ABN 51 640 926 718), We are open and dispatching daily. It just so happens I did some updating to my lighting last week (adding more LED strips to the existing old floresent fixtures). How can I tell if a flooded battery is bad? As such, it is important to detect battery problems at an early stage. That is, when the deep cycle battery isn’t under load and hasn’t been under load for a few hours. Measuring State-of-charge - Battery University, Currently Active Users Viewing This Thread: 1. Note: if you have multiple batteries connected together, each battery should be disconnected and charged/tested separately. I just tested a 225 ahr deep cycle battery that is in good working order.. Indeed, a typical cycle for a deep cycle battery would start at 100% capacity, followed by discharge of the battery to between 20 and 50% of its original capacity, and then recharge back to 100%. Conducting a Voltage Drop Test. Allow each battery in the system to stand on open-circuit for about one hour. Also, inspect the battery for broken or loose terminals; they are dangerous as they may result in short circuits. My question: I know that battery voltages drop when under a load. The best thing to do is recycle the thing. 🔋 RV Battery Voltage Overview: Any battery wita a CCA rating is not a true deep cycle battery. Thanks, folks. Hi! I have a pair of 12 volt deep discharge batteries wired in parallel that drop from 12.6 to 11.6 volts at their terminals while supplying about 140 amps to an inverter to run a microwave for 20 seconds. With a 12v fridge running and the compressor kicked it, it’s completely normal to see the voltage drop by as much as 0.5v-0.7v. Load Test Inspection. More than this indicates a possibly faulty or failing battery. If the battery voltage spread exceeds .15 volts for a 6-volt battery, or ..... What you describe is normal. Measure While “At Rest” “Open Circuit” Note: For best accuracy when measuring battery voltage, the battery must be in ‘open circuit’ condition (at rest, or ‘resting’).