How to Troubleshoot a Golf Cart Battery Charger
- Why is my golf cart battery charger not working?
- I manually charged my batteries, that did not work, now what?
- Do I have a battery or a charger problem?
- What are some symptoms of a bad golf cart battery charger vs. bad batteries?
- Is my 48 volt Club Car on-board computer (OBC) malfunctioning?
- Are my batteries completely charged?
- What if my batteries' voltage is too low, can they still be charged?
- Can I leave my golf cart charger plugged in for long periods of time?
- Does my charger automatically stop charging once the batteries are fully charged?
- Should the golf cart charger make noise while charging?
- My charger gets really hot and smells, is that normal?
- Why is my battery charger is showing a red flashing light?
- What if my golf cart doesn't drive very far after a full charge?
- Why are my batteries boiling?
- If I plug my charger into the wall, but don’t plug it into the golf cart, will the charger turn on?
Golf Cart Charger Questions
- How do I choose a replacement charger for my Powerdrive, Powerwise, etc.?
- What's the difference between the Links & Summit charger?
- How long does it take to charge a golf cart?
- Should I charge the golf cart after each use?
- Should I charge the golf cart in "Run" or "Tow"?
- Where is my owner's manual for my Lester charger?
- What is the deal with amps and how many amps should my charger have?
- What is "storage mode" on my Lester battery charger?
- Does my charger have the "storage mode" feature?
- Does my Powerwise or Powerdrive charger have the storage mode feature
- If I have an offboard charger, can I switch to an onboard charger?
- Can I use my "off-board" charger "on-board" my golf cart?
- Where on the golf cart do I install a Lester onboard battery charger?
- How do I connect the Lester on-board charger to my golf cart batteries?
- What is the blue wire on the Lester onboard battery chargers?
- Can I use a 36 volt charger on a 48 volt golf cart?
- Can I swap out plugs on my 36V or 48V charger?
- Can I use my charger (or the Lester chargers) on a GFCI outlet?
- What power source is needed for golf cart chargers, 110/120V or 220V?
- Do you sell used or refurbished chargers?
- Can my golf cart charger be repaired?
- How much does it cost to repair a golf cart charger?
- Do you repair chargers?
- Do you buy used chargers?
Golf Cart Battery Questions
- Do I have 6v, 8v or 12v golf cart batteries?
- Do I have a 36 volt or 48 volt golf cart?
- How long do golf cart batteries last?
- How can I make my golf cart batteries last longer?
- What is that white stuff on the batteries?
- Can I jump my golf cart batteries with jumper cables?
- Can I manually charge golf cart batteries with a car charger?
- Can I use car batteries for my golf cart?
- Do you sell golf cart batteries?
- Should I buy repurposed batteries?
- What is the difference between Wet-Cell & AGM Batteries?
- Do I need a golf cart battery watering system?
How Do I Troubleshoot My Golf Cart Battery Charger if It Isn't Working?
This is a VERY common question. Often we hear customers say that their golf cart battery charger does not work, or that it will not kick on and is showing no signs of life. Just so you know, this situation happens EVERYDAY. The first question we always ask is, how long has it been since you've charged your batteries? We ask this because often times if it has been a while (a couple weeks or more), or if you just got brand new batteries, or if your batteries have been really run down recently, it is possible that the batteries may not have enough voltage in them for the charger to start working. An automatic golf cart battery charger needs a minimal amount of voltage in the golf cart battery to even start working. They need somewhere in the range of 20-35 volts in the batteries to allow the chargers to know that they are connected up to batteries and to kick on.
Even if you are able to drive your golf cart and even if you just got brand new batteries, we'd suggest getting a 6V OR 12V CAR BATTERY CHARGER AND MANUALLY CHARGING UP THE GOLF CART BATTERIES FOR A COUPLE MINUTES EACH. This process should give the batteries enough voltage so that your golf cart battery charger can then take over. At a minimum, this process will eliminate low battery voltage as a potential issue. This should take no more than 15-20 minutes of manual charging in total.
Here's a video to help you manually charge your dead golf cart batteries:
This situation happens fairly often because people leave town for a couple weeks without charging their golf carts, or they discharge the batteries a little too much and the batteries' voltage drops way down. For the Lester chargers that we sell, we always suggest just leaving your charger plugged in all the time when you're not driving because the Lester battery charger will keep your batteries charged up if the voltage starts to drop. This is because every Lester charger has the winter "storage mode" feature (read below for more information on the winter "storage mode").
I manually charged my batteries, that did not work, what else can I do?
The second thing you should do after you charge up the batteries is to CHECK EVERY BATTERY CONNECTION. Make sure every battery cable is correctly wired. Then check that all the battery cables are tight against the battery terminals and are not rusted or corroded. Bad connections will cause any battery charger to not function properly.
After you've charged up your batteries and checked every connection and you are still having issues, it's probably safe to say you've got a golf cart battery charger problem and may need to service it or buy a new one. We do not service older chargers, but here's where you can purchase a new battery charger.
If you previously purchased a Lester battery charger from us, the next step is to give Lester Electrical (the manufacturer) a call directly to troubleshoot. They are the most knowledgeable with regards to your charger and handle all advanced troubleshooting. They are always happy to help our customers troubleshoot their issues. Here is the contact information below:
Lester Electrical Technical Support
Phone: (402) 477-8988
Hours of operation: 8:00 am to 4:30 pm CST Monday through Friday
How do I know if I have a battery problem or a charger problem?
Very often it's a battery problem. The easiest way to determine whether you have a charger problem is to test your charger on another cart, or test another cart's charger on your cart. We do understand that this is not always possible for most customers.
How to Read a Golf Cart Battery Charger
To find out for sure whether your batteries are the culprit, you’ll need a Digital Voltage Tester to test and read each individual battery. You’ll want to completely charge your golf cart before testing. While the charger is running, test your volts every 15 minutes. Whenever you see the same voltage back to back, that's how high your batteries' voltage will go and will give you an idea how good the batteries are. If you have a 36 volt system with 6 volt batteries, you’ll want to see readings of around 6.2 to 6.3 volts per battery (37.2 to 37.8 total volts). If you are showing something like a 4 volt charge on a 6 volt golf cart battery, you have a bad battery and will want to replace it. One bad battery can bring the performance of the entire set down. If you have a 48 volt system with 8 volt batteries, you’ll want to see readings of around 8.2 to 8.3 volts per battery (49.2 to 49.8 total volts). If you are showing something like a 6 volt charge on an 8 volt battery, you have a bad battery and will want to replace it.
What are some symptoms of a bad golf cart battery charger vs. bad batteries?
Bad Batteries: IN GENERAL, if the charger doesn't kick on or show any signs of life when you plug it into your cart, this is most likely a battery/connection issue. Learn more about the signs of a bad golf cart battery.
Bad Charger: IN GENERAL, if the charger kicks on, but doesn't charge fully or kicks off soon after, this is likely a charger issue. If the charger makes a loud clicking noise, this is likely a battery charger issue. If the charger will not shut off or never stops charging, this is likely a battery charger issue as the internal "brain" is defective (unless you have a 48 volt Club Car (see below)).
Club Car Charging Problems
I have a 48 volt Club Car, I individually charged my batteries as described above, but the charger still doesn't work, what now?
You may have a non-functioning OBC (onboard computer). Since 1995, 48 volt Club Cars come with an OBC that regulates the batteries' charge. When you plug the charger into your Club Car, the OBC will tell the battery charger when to start and stop charging based on the voltage levels in your batteries. As a result, golf cart battery chargers for 48 volt Club Cars need a working OBC to get them to start charging. So, it is possible that your OBC is malfunctioning and it is not the golf cart charger. Again, this is only for 48 volt Club Car golf carts (Not for Yamaha or EZGO golf carts). If you have not manually charged your batteries and checked your connections, please do those first before assuming you have an OBC issue.
With that said, if the OBC on the Club Car is functional and the batteries are above 35 volts, you should hear a "click" from the relay inside the charger when the round plug is inserted into the cart. If no click is heard the problem is either that the battery voltage is too low (less than 35 DC volts) or there is a problem with the OBC or a fuse. The only other reason the relay will not click is if it is a bad relay (a failed "open coil"). This is very rare and there have not been many documented out-of-the-box relay failures.
For more information on Club Car OBCs, check out our Club Car On-Board Computer (OBC) Frequently Asked Questions.
Are my golf cart batteries completely charged?
I charge my batteries, unplug it, then plug it in again and it starts charging again for another 30+ minutes or so. Is this normal?
If you have a Lester battery charger, yes, your batteries are completely charged and this is normal. Every time you plug in a Lester automatic battery charger, there is a sampling to get a reading of the batteries' voltage. The amps will shoot up, but then after a few minutes drop down quickly to the low single digits for a while (maybe 30-40 minutes). This is standard. The charger doesn't know immediately when you plug it in that you just charged the golf cart and that the volts are up; it needs to test them. Think about it like the charger has "amnesia" every time it gets plugged in to your Club Car, EZGO, Yamaha or other golf cart.
What if the battery voltage gets too low, will my charger charge my batteries?
No. Automatic golf cart battery chargers are not able to charge batteries that are completely discharged or dead. They require a minimal number of volts to begin charging. At least 20-25 volts across the set will be required for a 36 volt golf cart. At least 30-35 volts across the set will be required for a 48 volt golf cart. Please see above for charging dead batteries.
Can I leave my golf cart battery charger plugged in to my cart for extended periods of time without my batteries dying?
Yes, because our new Lester Battery Chargers have a winter storage mode feature that automatically regulates the batteries' charge. With a Lester charger you do not need to call a neighbor to unplug and re-plug your charger to kick on, it does it automatically and only when needed. This is a new and unique feature on Lester chargers that is not available on other chargers, like the Powerwise or Powerdrive chargers.
Will the golf cart charger automatically stop charging once the batteries are fully charged?
Yes. All automatic chargers are designed to charge your batteries until they are fully charged and then stop charging. So you do not need to manually shut off the charger or worry about overcharging your batteries. All Lester chargers are made with a number of internal safety mechanisms that ensure that they will never overcharge batteries.
Should my battery charger make noise when it is charging?
Yes, the heavy duty battery chargers will hum or buzz, so if it's buzzing or humming you know it's working.
My Charger gets really hot and gives off a bad small, is that normal?
It is normal for a charger to get a little warm and maybe a bit hot from time to time as it's working. Sometimes there may even be an odor. It really depends on the battery charger and how long it's been running and how hard it has to work. The charger may get hot from time to time depending on how far the batteries were discharged and how long it takes to bring the batteries back up to 100% charged. But here are a few general tips to keep the charger from overheating:
- Make sure that your battery cable connections are correct, clean and tight. Bad connections can cause a charger to overwork and overheat.
- Ensure that you have adequate water levels in your batteries.
- Do not use an extension cord. If you must use one, just use a heavy-duty extension cord. A cheap extension cord can cause the charger to overheat.
- Give the charger room to breathe and make sure it is on a hard surface, preferably the garage floor.
With that said, if the golf cart charger is always hot and always giving off a bad smell, you should contact the manufacturer to confirm that everything is functioning properly.
If I plug my golf cart battery charger into the wall, but don’t plug it into the receptacle on my golf cart, will the charger turn on?
No. If you plug your charger into the wall but not plug it into the receptacle on your golf cart, you will not see any signs of life from the charger (i.e. humming, buzzing, heating up, lights coming on, etc.). The plug on your golf cart charger needs to make connection with the holes/leads within the receptacle on your golf cart in order to kick on. The charger needs to be connected to battery voltage. Even if you connect up a volt-meter to the charger, it will not give off any voltage. So in short, the charger will not do anything without being connected to your golf cart.
What does a red flashing light mean on my battery charger?
Every golf cart battery charger is different with respect to indicator lights, but in general the red light is a fault light that indicates something is wrong with the charging process. Occasionally a red fault light on a golf cart charger can mean that the batteries do not have enough voltage in them to allow the charger to kick on (see Charging Dead Golf Cart Batteries above). However, most of the time, especially with EZ-GO Powerwise chargers, this is the "red light of death" or an internal charger failure indicating that the charger needs to be serviced or replaced.
What if I charge my batteries until my battery charger stops charging, but my golf cart won’t drive very far?
You probably need to test your batteries and likely will need to get new golf cart batteries.
The water in my wet-cell batteries is boiling while charging the batteries. Why?
A couple of factors could go into this: You may have too much water in the batteries (should be approximately ¼ inch above the plates). You may also have a battery or two that is old/dead/failing, which could be causing the charger to boil the rest of the batteries in an effort to get them all fully charged. We would recommend checking all of your batteries/connections.
How do I replace my Powerdrive, Powerwise or other brand of charger?
Please see our guide on How to Buy A Golf Cart Charger.
What's the difference between the Links & Summit charger?
Please see our Lester Battery Charger Guide.
How long does it take to charge a golf cart?
The quick answer is, it depends. It depends on three factors, 1) the quality of your batteries, 2) how discharged your batteries are and 3) the quality of your charger. If you have 5 year old batteries that are very discharged and you have a lightweight 2-5 amp charger, it may take a very long time (10 hours or more). If you have brand new batteries, they are 20-30% discharged and you've got a heavy-duty charger, it can be pretty quick (1-3 hours). Again, it depends on all of the above factors, so it really could vary quite a bit.
Should I charge the golf cart after each use?
Yes. It is healthy for the batteries to be fully charged at all times. So, you should charge your golf cart every night. Automatic golf cart chargers will shut off once the batteries are fully charged, so there isn't a concern that they will be over charged.
Should I charge the golf cart in "Run" or "Tow"?
Run. Your golf cart should be switched to "Run" anytime you are using the cart or charging your batteries. "Tow" is only for long term storage if you are planning on removing the batteries.
Where is my User’s Manual for my golf cart battery charger?
Our manufacturer does not provide owner’s manuals. Here are the links to the Lester charger manuals (they are also linked to on our product pages):
- Lester Electrical Golf Cart Battery Charger Owner's Manual - Model 28080 & 28100
- Lester Electrical Golf Cart Battery Charger Owner's Manual - Model 26610
- Lester Electrical Golf Cart Battery Charger Owner's Manual - Model 27800, 28120 & 27940
- Lester Electrical Summit 2 Charger 1050W Manual
- Lester Electrical Summit 2 Charger 650W Manual
What is the deal with amps and how many amps should my golf cart battery charger have?
Here's the deal with amps, the more amps that a charger has, the faster the charger will charge your batteries. However, it really is a balance between getting enough amps that your battery charger charges quickly, and not putting too many amps on the batteries so that the batteries have a shorter life span. So the moral of the story is, more is not always better with respect to amps. With that said, for a 48 volt golf cart, 13 amps has been found to be the right balance between charging speed and long-term battery stress. For a 36 volt battery charger, 21 amps is standard. You'll want to avoid purchasing a charger with low amperage (2-5 amps) as it will take forever to charge your batteries.
What is “Storage Mode” on my golf cart battery charger?
"Storage Mode" is a feature that comes with every Lester Electrical golf cart battery charger that we sell (except for the 48V Club Car Charger - That battery charger is ONLY automatic, meaning it will charge to full charge and then shut off. It will not come back on like the new Summit II battery chargers). When you plug in your charger to your cart it will fully charge the batteries. Once fully charged, the charger goes into its "storage mode" feature so long as it is connected to the golf cart and the wall. When in storage mode, it will charge your batteries only when the following two situations occur (1) the battery voltage drops to a certain predefined voltage AND (2) 10-15 days have elapsed. Once these two criteria are met, the charger will do a refresh charge to bring up the volts again to 100% fully charged. So, unlike a trickle charger that charges non-stop, the Lester charger charges only when the batteries need a good charge.
Again, this is how all Lester automatic battery chargers work (except for the 48V Club Car Charger). You can leave the charger plugged in even when you're gone for long periods of time (months), and your batteries will not die because they'll get a charge from time to time to keep the volts up. If you are leaving for an extended period of time it is recommended that you plug your charger into a surge suppressor with at least 2,400 joules (i.e.: a surge suppressor made by Tripp Lite or Belkin).
Will my golf cart battery charger have the “winter” storage mode feature?
All Lester battery chargers (except for the 48V Club Car Charger) have the storage mode or battery healthy feature. If you do not have a Lester charger, you do not have the winter storage mode feature.
Does my Powerwise or Powerdrive charger have the storage mode feature?
Generally the Power Wise / Power Drive chargers do not have storage modes. This means that you'd need to unplug them and plug them back in if you want to re-charge your batteries.
If I have an offboard charger with a plug, can I switch to an onboard charger without a plug that connects directly to the batteries?
Yes. The overwhelming majority of golf carts come with offboard chargers attached to plugs. Some golf carts come with onboard chargers affixed with ring terminals or plugs. It is perfectly fine to switch from an off-board charger (with a plug) to an on-board charger (with ring terminals that connect directly to the batteries).
Can I use my "off-board" portable charger "on-board" my golf cart?
You shouldn't take an off-board charger and put it on the golfcart and use it like an on-board charger. They're just not designed for that kind of use and can get damaged. Off-board or portable chargers are not made to handle all the bumps and potholes. On the flip-side, if you currently own an on-board charger that is wired into the cart, you can take that on-board charger and affix a DC plug and use it as a portable charger (off-board). In recap: If you're taking an on-board charger and using it off the golf cart, you're good to go! But, you should not take an off-board (portable) charger and put it on the golf cart and use it as on on-board charger.
Where on the golf cart do I install a Lester on-board battery charger?
The answer is, it depends. It's really where ever you are able to find space for a shoebox sized charger on your golf cart. Some find that they can fit the on-board charger under the seat. This will really depend on the cart's specific battery configuration (x4 12V's, x6 6V's, x6 8V's or x8 6V's). Others will put the onboard charger on the little cubby area below the rear seat (if they have one). The Lester Summit onboard chargers that we sell have the following dimensions: L 10.95" x W 7.3" x H 4.75" and are pre-drilled mounting holes on the sides. Here are links to each: 48V Onboard Charger and 36V Onboard Charger.
How do I hook up the Lester on-board charger to my batteries?
You just hook up the red wire (the positive) to the positive terminal on the first battery in the set, and then hook the black wire (the negative) to the negative terminal on the last battery in the set. So, positive to positive, negative to negative. Forget about the blue wire (for more on the blue wire read What's the Blue Wire?). The ring terminals on the leads are universal and will fit on all batteries. Because all of the golf cart batteries are connected with battery cables, all batteries will be charged in series.
What is the blue wire on the Lester onboard battery chargers?
Most people are familiar with the red wire, which is the positive lead, and the black wire, which is the negative lead. Only the red and black wires are needed to completely charge the golf cart. The blue wire is an optional safety wire. If hooked up to the motor controller it will not allow you drive the golf cart while charging it. Think about being at the gas pump and driving off with the pump still in the car. The blue wire is not installed very often.
Can I use a 36 volt charger on a 48 volt golf cart?
No. You must match volts to volts. A 36V cart requires a 36 volt golf cart charger. A 48V cart requires a 48 volt golf cart charger. You can burn up your batteries if you do not charge with the proper voltage. Check out our 36V vs. 48V Guide for more information.
Can I swap out plugs on my 36V or 48V charger?
Answer is, it depends. If you have a 36 volt charger, the answer is always yes. For example, if you have a 36V Club Car charger with the crowfoot plug, and you want to use that charger for another 36V EZ-GO golf cart that takes the "D-shaped" plug, you can remove the crowfoot plug and attach the D plug, no problem. Really, any 36V charger, you are good to go. With 48 volt chargers, the same applies (you can swap out plugs), EXCEPT when you are attempting to use a 48V Club Car or its charger with the round 3-pin plug. The 48V Club Car chargers are completely different than all other golf cart chargers. They do not have the internal automatic shutoff, the Club Car onboard computer actually controls the shut off. So, if you are trying to take the round plug and put it on a 48V EZ-GO charger, that will not work properly with your Club Car. Visa versa, if you take a 48V Club Car charger and put on an EZ-GO triangle shaped plug, that will not work either with your EZ-GO. Bottom line is, swapping plugs on a 36V charger is fine. Swapping plugs on a 48V charger is also fine, UNLESS a 48V Club Car or 48V Club Car charger is involved.
Can I use my charger (or the Lester chargers) on a GFCI outlet?
Yes. The Lester chargers work perfectly with GFCI as well as grounded outlets. Other chargers work as well with GFCI outlets, but you may want to confirm with your manufacturer.
110/120 Volts (110V/120V) vs. 220 Volts (220V). What power source is needed?
When comparing 110V with 220V AC inputs, you have to keep in mind that they both essentially do the same thing. That is, they produce power to operate electrical outlets. What’s important to know is that different countries run on different voltages. If you’re located in the US or Canada, your home is wired for 110-120 VAC, and as a result you’ll need to make sure that you choose a battery charger rated for 110-120 VAC, 60 Hertz (Hz) input. If you’re located in an international country (South America, Europe, Asia, etc.), they run on 220V, so you’ll need a battery charger rated for 100-230 VAC, 50-60 Hertz (Hz) input.
Do you sell used or refurbished/rebuilt golf cart battery chargers?
No. We only sell brand new products.
Can my golf cart battery charger be repaired?
It depends. If your charger has a completely sealed casing, it cannot be repaired. Many of the lightweight "wafer" 2-5 amp chargers, as well as some of the Powerwise chargers come with sealed aluminum casings and cannot be repaired. If you have a battery charger that has an exterior that can be unscrewed and taken off, your charger likely can be repaired. The chargers that can be repaired have transformers, capacitors and other parts that can be swapped out.
How much does it cost to repair my golf cart battery charger?
Obviously this depends. In general, with the cost of parts and service, we've found that a good estimate is somewhere in the range of $150 to $250.
Do you repair used battery chargers?
No. We only sell new battery chargers. We do not repair older chargers.
Do you buy used golf cart chargers?
Do I have 6 volt, 8 volt or 12 volt golf cart batteries?
See our Golf Cart Battery Volts Guide.
Do I have a 36v or 48v golf cart?
See our Golf Cart Battery Voltage Guide.
How long do golf cart batteries last?
If golf cart batteries are properly maintained they generally will last for around 5-6 years.
How can I make my golf cart batteries last longer?
See our Golf Cart Battery Maintenance Guide.
What is that white stuff growing on the top of my golf cart batteries?
That’s corrosion. You will need to clean it off because if it builds up it may cause the battery cables to lose contact with the battery and keep your cart from running. Again, please see our Golf Cart Battery Maintenance article for further details.
Can I use jumper cables from my car to jump start my golf cart batteries?
No. Using a car to jump deep cycle golf cart batteries can ruin them.
Can I manually charge golf cart batteries with a car charger?
Yes. Please see Charging Dead Golf Cart Batteries above.
Can I just replace my golf cart batteries with regular car batteries?
No. Regular car batteries are not made to be discharged as much as deep cycle golf cart batteries. So you don't want to use regular car batteries on your golf cart.
Do you sell golf cart batteries?
Yes! We now offer 6V, 8V & 12V Trojan Golf Cart Batteries. We sell new Trojan Battery and Powertron branded batteries. Please see here for more details on choosing a battery.
Should I buy repurposed, refurbished or rebuilt batteries?
No, it is recommended that you buy new deep cycle batteries. Refurbished batteries usually have the same lead but just new acid and a new plastic exterior.
What is the difference between Wet-Cell Batteries and AGM Batteries?
There are two types of popular deep-cycle lead acid batteries that are used today: Wet-Cell and Sealed (AGM). Wet-cell batteries dominate the golf cart, utility vehicle, scissor lift, and material handling machine markets (99%). The reason for this? Wet-cell batteries generally have a more favorable cost/benefit ratio compared to sealed batteries, and although their maintenance needs are higher, they have a history of proven performance and industry acceptability. Now onto sealed batteries: The primary advantage of a sealed battery is that it will not emit corrosive gases during use or charging, and will not spill acid if tipped over. This makes them more popular for wheelchair manufacturers, and are growing in popularity in the floor-care machines markets for use in hospitals, nursing homes, etc. due to the increasing expectation of no acid spills, minimal maintenance, and non-corrosive gas emissions.
Do I need a golf cart battery watering system?
The quick answer is no. In wet cell batteries, acid and water routinely evaporate from the batteries cells. This causes batteries to lose power and not last as long. Keeping your wet cell batteries’ water levels filled to the proper levels (roughly ¼ inch above the plates) extends the life of your batteries and makes them perform better on a single charge. Generally, golf cart owners pour in distilled water by hand with a filling bottle. A battery watering system is automatic so it eliminates the need to manually fill your batteries, which can be super convenient! On the flip-side of the convenience, battery filling systems can get a bit costly to purchase and also to maintain. Whether you fill your golf cart batteries by hand, or using a filling system, always make sure you keep your water levels properly maintained.
If you're looking for a new charger you can shop online with Golf Cart Garage!
You can also check out some of our other great articles at our Resource Library. A few other great FAQs are our Tires FAQ, Wheels & Lift Kit FAQ and our Lights FAQ.