5 Best Battery Filler Bottles with Automatic Shutoff

If you want to add water to lead-acid batteries without worrying about overfilling or spilling the fluid, use one of these battery water fillers with automatic shutoff.

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The electrolysis process in a deep cycle battery often results in a substantial loss of water. This causes the ratio of water to sulphuric acid to drop as well as the electrolyte level. The electrolyte also loses its strength, thereby impacting negatively the battery capacity and the battery’s overall performance. , making the battery electrolyte lose its strength. A drop in the electrolyte level the battery capacity and its overall performance.

If the electrolyte level is not checked for a long time, it can run very low and expose the plates. As a result, the lead plates on your deep cycle power bank may undergo irreversible damage, leaving you with one option. To replace the battery.

Good thing is that maintaining a proper electrolyte level can keep your lead acid battery in good condition and in optimal performance. You can do this by regularly checking the electrolyte level in the battery and refilling it with battery water when necessary.

One of the best ways to refill a lead-acid battery is by using a battery filler bottle.

What is a battery filler?

A battery water filler is a bottle with a spout designed for topping up a serviceable battery with distilled water. The best battery filler has an automatic shutoff mechanism that shuts off the flow of water when electrolyte reaches maximum level. It helps prevent overfilling water or spilling the electrolyte.

battery filler bottle
Battery filler bottle

Although you can still refill a flooded lead-acid battery without using designated equipment, it is more efficient and effective to use a filler bottle. Otherwise, you might spill a lot of water while you try trying to aim the battery vent with an ordinary jug.

Water spills can make a smooth floor slippery and a potential trip hazard. Even worse, overfilling a battery can cause the electrolyte to boil over during the charging cycle and cause serious acid hazards. The acid may even corrode the floor of your store.

I know it can be difficult to find a good battery filler. This is why I share the 5 best battery filler jugs on the market. All of them have an automatic shutoff to make your battery maintenance exercise fun and less hectic.

You can use any of them to service car batteries or larger battery banks such as RV batteries, golf cart batteries, or solar plant lead-acid battery bank. You will be surprised by the difference they can make.

Best Battery Water Fillers

Performance Tool W54274 Battery Filler (2QT) With Auto Shut Off

performance tool battery water filler

The Performance Tool W54274 battery water filler has a 2 quartz capacity and an automatic shutoff nozzle. The bottle is made of durable injection-molded plastic which makes it retain its shape even when you press it down hard against the cell vent.

The most unique thing about this unit is that it has two openings; one at the top for adding water and the spout for pouring water into the battery. The spout has a spring-loaded valve that prevents the nozzle from getting stuck when you remove the filler from the battery.


  • Has an opening at the top for adding water
  • The filler cap fits tightly to avoid air leakage
  • Sturdy body to withstand the force of pressing it down on a hole when adding water to the battery
  • Fairly priced


  • Can overfill battery if the cap is not well-fitted.
  • The internal spring on the spout is not stainless steel It can become rusty over time and fail.

Overall, the Performance Tool Battery Filler is designed to eliminate the hard chores of watering batteries. The top opening makes refilling the bottle an intuitive task. This filler bottle is a must-have if you have multiple batteries to refill. It is a good choice for refilling golf cart batteries. The unit is also the least expensive but certainly a good value for your money.

LubriMatic Battery Water Jug Review

lubrimatic battery water jug

Plews 75-030 auto shut off battery filler is definitely a clever way to retire the funnel you use to add water to RV and golf cart batteries. This plastic watering bottle for batteries has a 2-quart capacity, enough to refill a bunch of batteries before the next replenishment. The spout cuts off fluid automatically to avoid overfilling the cells.

Furthermore, the valve tip is a double-action fast flow type that helps prevent after drip. This ensures that you don’t get into contact with the corrosive battery electrolyte. The filler is made of tough polyethylene which makes it safe to use with acid.


  • Safe to use with battery acid
  • No risk of overfilling or spilling
  • Has two openings for easy refill
  • Inexpensive


  • Has only one opening for both adding water and fitting the nozzle

Overall, the LubriMatic 75-030 2 Quart professional battery water filler is a handy long-lasting tool for servicing lead-acid batteries. It increases safety and efficiency in the battery water refilling exercise. Its spout is ideal for batteries with at least 5/8″ vents. This means you can use it to refill batteries in your RV, golf car, or batteries in your solar shed.

MightyMax Deep Cycle Battery Water Filler Review

mighty max battery filler

When working in a garage, you are likely to touch different automotive fluids. The last thing you want are tools that will degrade on coming into contact with those fluids. The MightyMax Deep Cycle Battery Water Filler is an ideal water filler for use in such an environment.

It is exceptionally resistant to automotive fluids that are likely to come into contact with it when servicing batteries. The filler has a single opening just like the LubriMatic filler. You open it to refill the bottle and attach the spout to pour water into the battery cells.

The spout or nozzle features the double-action fast flow valve tip that prevents fluid from dripping after withdrawing from the cell vent.


  • Does not overfill or underfill
  • Easily accesses very tight places
  • No leaks or spills unless broken
  • Easy to use


  • You have to push too hard to get water to come out
  • The plastic is quite thin. It folds easily under pressure.
  • Sometimes the cap on the spout assembly can cross threads when reinstalling and cause the filler to leak.

The MightyMax Deep Cycle Battery filler is a good choice for filling car batteries and generally for garage use because of its resistance to automotive fluids. Its downside is that it is not sturdy enough and tends to bend when pressed down hard.

OTC 4621 Two-Liter Battery Fill Bottle

OTC 4621 battery water bottle

If you are looking for a battery filler that is made of heavy plastic material and looks durable, then the OTC 4621 Two-Liter Battery Filler should be one of the options. It has two openings like the Performance Tool battery filler but feels sturdier and costs three times more.

The fill cap fits tightly without allowing any air incursion. The cap needs to close tight if you want the filler bottle to operate as intended. This OTC battery watering device dispenses water quickly and easily and stops exactly when the cell is full. Exactly on the lower line.


  • Easy to use
  • Easy to add water to the device through the top opening


  • The unit does not work well when the filler cap is not tight enough.

Although OTC 4621 Battery Filler is the most expensive, it is also the most durable and quite easy to use. It is a good alternative to your funnel and flashlight. You can be sure it will top off batteries to the right level while leaving the floor as dry as you found it.

Stone River Golf Cart Water Filler Review

stone river battery filler

Despite a relatively high failure rate score among buyers, Stone River Battery Filler is still better than a funnel. Its drip-free design ensures that battery water does not spill when refilling batteries.

The Stone River filler is made of tough polyethylene material to ensure durability. It has two openings just like the OTC 4621. However, its automatic shutoff nozzle has a high failure rate because the threads can get chewed up quite easily if you are not careful. This causes the unit to leak because the cap cannot seal properly.

A good way to get around this problem is to place a nylon bag on the mouth before placing the cap.

Another challenge with the stone river battery water filler is that you need to exert a good amount of pressure on the spout mechanism to activate it. Despite these challenges, the unit is still better than nothing.


  • Very easy to use
  • Has a top opening for adding water


  • Not very strong on the seams
  • May overfill batteries sometimes

Final Words

Battery fillers are great for topping up batteries in your car, RV, golf cart, or electric cart with no spilling. They make the chore of keeping the battery serviced easier, faster, and safer. These simple devices make a task that was always messy and quite dangerous very safe, fast, and easy. No more electrolyte spills and no more balancing a gallon of distilled water over a battery whole.

Battery filler jugs beat filling with a funnel for efficiency and beat a battery watering system for the price. When buying, however, it is good to know how the nozzle and the top cap fit. If either of these two parts does not provide an air-tight seal, then the jug will definitely malfunction and it will not serve you as expected.

Our favorite battery water fillers from the 5 units are Performance Tool’s golf cart battery filler because of its price and the double-opening design followed by Plews Lubrimatic filler jug because of its sturdy construction. The others are also good and even cheaper. So, just follow your heart and pick the one that ticks the most boxes.

Why Maintain Car Battery?

Under the hood of your motor vehicle, you will probably find a flooded battery that powers accessories and enables your car to start. In order to keep the battery in optimal performance and extend its life, you need to occasionally carry out some maintenance practices. Two very important battery maintenance procedures I would recommend include:

1. Checking the strength of battery electrolyte.

This procedure involves the use of a battery hydrometer or refractometer to measure the specific gravity of the battery electrolyte. The readings are recorded, temperature corrected and then compared against the voltage measured across the terminals of the battery to determine the state of charge and the overall health of a battery.

2. Checking the battery electrolyte level.

This method involves inspecting the deep cycle battery to check the electrolyte level. If the battery acid level is below the battery plates or barely covers the plates, carefully top up with battery water to the correct level without spilling, underfilling, or overfilling.

There are several ways of adding water to a car battery or any other deep cycle battery that is not maintenance-free. You can use a funnel, pro-fill watering kit hand pump, battery filler bulb, hydrometer, or battery filler. However, the easiest and most affordable method is by using a battery water filler. This battery water filler bottle with automatic shutoff ensures you only add water enough water to the battery without overfilling or spilling.

A battery filler is a relatively cheap, easy-to-use, handy little bottle fitted with a spout for feeding water into a battery to the correct level. Most battery fillers have nozzles fitted with an automatic shutoff valve that detects the level of electrolyte and automatically cuts off the flow of water to avoid overfilling.

How to use a battery filler in seven simple steps

how to add water to battery with battery filler

Although battery water fillers come in different sizes, colors, shapes, and structures, they function almost the same way. This is probably why most of them don’t even come with a user manual, which makes it difficult for a first-timer to use the tool effectively.
But because we care, we have gone out of our way to publish the standard procedure for using most if not all the battery filler bottles on the market. We want to make it easy for you to transition from using a funnel to using an intelligent filler that makes light the work of maintaining deep cycle batteries.
The following is a simple seven-step procedure for using a battery filler bottle when maintaining your deep cycle batteries.

Time taken depends on the number of batteries

  1. Fill the battery water filler with battery water.

    Normally, you will come across two types of battery filler bottles; ones with only one opening and those with two. For fillers with only one opening, you will have to remove the spout or nozzle in order to fill the cylinder with water. Then replace the nozzle and torque it tightly to prevent water from spilling. For battery filler jugs with two openings, remove the bottle cap at the top, add battery water, then replace the cap and torque tightly to prevent air incursion.

  2. Remove the vent cap from the battery cell.

    Ensure you are wearing your safety goggles and a pair of latex gloves to avoid corrosion with acid.

  3. Put the spout into the battery vent and press it down.

    Stick the nozzle of the battery filler into the battery hole perpendicularly and press it down.

  4. Add water to the battery cell.

    As you press the spout against the mouth of the cell vent, you will hear the water gurgle as it flows into the cell. If the battery filler has an automatic shutoff, the flow, as well as the gurgling, will stop as soon as the required level of electrolyte is reached. Otherwise, check to see if the electrolyte has reached the correct level and stop adding fluid.

  5. Remove the spout from the cell and move to the next cell.

    Move to the next cell and remember to refill the bottle whenever it runs out of battery water during the exercise.

  6. Replace battery vent caps

    Once complete, replace the battery cell vent caps, wipe the top and drain any remaining water from the filler bottle.

  7. Store your filler bottle in a safe place.

    Rinse the filler bottle and store it safely in your tool storage area.

Always remember to rinse your battery filler with fresh tap water before storing it in your toolbox!


Hey there! I am an field electrical engineer by day, a blogger by night, and DIYer on weekends. Throughout my career, I have used many tools and learned that getting the right tool for the job is the first step to getting the job done right. This is why I write about tools and tests/reviews them on this blog.