Scissor lift batteries, especially flooded lead-acid types, require periodic watering to maintain performance and lifespan. Always use distilled or deionized water—never tap water—and add it only after full charging to the correct level (about 1/4 inch above plates).
Properly filling scissor lift batteries is essential for safety, reliability, and avoiding costly premature failure. This guide covers the correct water type, timing, fill levels, safety precautions, and tools that make maintenance easier. We’ll also explain why many operators are switching to maintenance-free lithium batteries.
What Type of Water Should You Use for Scissor Lift Batteries?
The only recommended water for flooded lead-acid scissor lift batteries is distilled or deionized water. These are purified to remove minerals and impurities that can damage the battery.
Tap water, well water, or bottled drinking water contain minerals (calcium, magnesium, iron) that deposit on the battery plates over time. These deposits reduce capacity, increase internal resistance, and shorten battery life significantly.
Key rule: Never use anything except distilled or deionized water. Distilled water is widely available at supermarkets, pharmacies, and auto parts stores for a low cost.
When Should You Add Water to Scissor Lift Batteries?
The best practice is to check and fill batteries only after they have been fully charged. During charging, the electrolyte expands and the water level rises naturally. Adding water before charging risks overfilling and acid overflow.
Exception: If the plates are exposed (visible above the electrolyte), add just enough distilled water to barely cover the plates before starting the charge cycle. Then complete the normal watering after the charge is finished.
Regular checks should be part of your maintenance schedule—typically every 10 charge cycles or monthly, depending on usage intensity.
How to Properly Fill Scissor Lift Batteries
Follow these steps for safe and accurate watering:
- Fully charge the batteries first.
- Wear proper PPE: acid-resistant gloves and safety glasses.
- Remove vent caps carefully.
- Check each cell’s level using a flashlight.
- Add distilled water until the level reaches approximately 1/4 inch (6 mm) above the plates or to the bottom of the split-ring fill tube (if present).
- Avoid overfilling—excess water can spill during the next charge and cause corrosion.
- Replace vent caps securely.
Many modern batteries have built-in level indicators or split rings that make it easy to see the correct fill line.
Safety Precautions When Handling Scissor Lift Batteries
Battery electrolyte is corrosive sulfuric acid. Always prioritize safety:
- Wear gloves and eye protection
- Work in a well-ventilated area
- Keep baking soda nearby to neutralize any spilled acid
- Avoid sparks or open flames—hydrogen gas can be produced during charging
- Do not lean directly over batteries while removing caps
Useful Tools for Easier Battery Watering
Manual watering with a jug works for small fleets, but larger operations benefit from specialized tools:
- Battery watering guns or syringes for precise control
- Automatic single-point watering systems (e.g., BWT, Flow-Rite) that connect all cells and fill them simultaneously to the exact level
- Deionizer kits for producing your own pure water on-site
These systems save significant time and reduce the risk of over- or under-filling.
How to Clean Battery Terminals and Prevent Corrosion
While watering, inspect terminals for corrosion (white powdery buildup). Clean them with a solution of 1 part baking soda to 1 part warm water applied with a brush. Rinse with clean water and dry thoroughly. Apply a thin layer of petroleum jelly or terminal protectant spray afterward.
What Can I Use Instead of Distilled Battery Water?
There is no safe substitute. Rainwater, filtered water, or reverse-osmosis water may still contain trace minerals and are not recommended. Using anything other than distilled or deionized water will void most warranties and accelerate battery degradation.
If distilled water is temporarily unavailable, delay watering until you can obtain proper water rather than risk damage with an alternative.
Why Many Fleets Are Switching to Maintenance-Free Lithium Batteries
While flooded lead-acid batteries are inexpensive upfront, the ongoing watering, cleaning, and risk of spills add labor and downtime costs. Modern Lithium Iron Phosphate (LiFePO4) scissor lift batteries eliminate all watering and most maintenance entirely.
Brands like hydrocell offer drop-in LiFePO4 replacements with built-in BMS, faster charging, longer lifespan (2,000–5,000 cycles), and no acid handling. The higher initial investment is typically recovered within 2–3 years through reduced labor, energy savings, and extended runtime.
For rental companies and indoor operations especially, the safety and convenience advantages make lithium the smarter long-term choice.
Final Tips for Scissor Lift Battery Care
Proper watering extends flooded battery life significantly, but following manufacturer guidelines is crucial. Always consult your specific battery and lift manual for exact procedures. By maintaining correct water levels and considering a switch to lithium technology from trusted suppliers like hydrocell, you’ll achieve maximum uptime and lowest total cost of ownership.