What is a Lead Acid Battery?
The lead acid battery was the first rechargeable battery ever created, invented in 1859 by Gaston Planté. While the technology has evolved, it’s still widely used today thanks to its reliability and cost-effectiveness.
If you want to understand how batteries actually store and deliver power, start with our guide to understanding battery power: watts, volts, amps and how they work together.
Types of Lead Acid Batteries
Lead acid batteries generally fall into two main categories:
1. Flooded Lead Acid Batteries
These include:
- Calcium maintenance-free
- Maintenance-free deep cycle
- Maintainable flooded lead acid (lead antimony) — these require regular water top-ups
2. Sealed Batteries (No Maintenance Required)
- AGM (Absorbent Glass Mat)
- Gel batteries
Important: AGM and gel batteries are sealed and must NOT be opened or watered.
Why Maintenance Matters
A maintainable flooded lead acid battery needs regular care to perform properly and last as long as possible.
Think of it like this — just like your body needs water to function, so does your battery.
If water levels drop too low:
- Internal components can be damaged
- Battery life is shortened
- Performance drops off
Correct terminal condition also plays a big role in performance. If you’re unsure, read our guide on battery terminals explained and why they matter.
How to Maintain Your Flooded Lead Acid Battery (Step-by-Step)
1. Safety First
Always wear gloves and eye protection.
Check the battery label to confirm it is serviceable before opening it.
2. Check Water Levels Regularly
Keeping the correct fluid level is key.
How often to check:
- Daily use → check weekly
- Occasional use → check monthly
- Hot weather → check more frequently
Avoid:
- Overfilling
- Letting levels drop too low
3. Charge Before Topping Up
Always charge the battery before adding water.
- Charge when battery drops to around 25%
- Fully charge before topping up
- Add water to about 10mm above the plates
Partially charging can damage the battery and shorten its lifespan.
If you want to better understand how battery performance is measured, see battery ratings explained in simple terms.
4. Use Distilled Water Only
Never use tap water.
Tap water contains minerals that can:
- Damage internal components
- Reduce battery efficiency
- Shorten lifespan
Distilled water is cheap, easy to find, and far better for your battery.
Common Mistakes to Avoid
- Letting water levels drop too low
- Overfilling the battery
- Using tap water
- Charging incorrectly or not fully charging
- Opening sealed AGM or gel batteries
How Long Will a Maintained Battery Last?
With proper care, a maintainable flooded lead acid battery can last significantly longer than a neglected one.
Regular maintenance:
- Improves performance
- Extends lifespan
- Saves you money long-term
When to Get Help
If you’re unsure about:
- Water levels
- Battery condition
- The right battery for your setup
It’s always better to ask than guess.
Need Help or a Replacement Battery?
Visit Battery Warehouse — your local battery experts for friendly advice and reliable battery solutions.
We’ll help you:
- Choose the right battery
- Get maximum performance
- Avoid costly mistakes
Or give us a call on 0800 228 748.
