Does phosphoric acid improve cycle life in lead–acid batteries?

Phosphoric acid has been used as an additive in lead–acid battery electrolytes, but not as a replacement for sulphuric acid.

When added in small amounts, phosphoric acid forms stable compounds on the positive plate that help reduce corrosion, shedding of active material, and sulphation. This effect can noticeably extend the cycle life of a battery, especially under deep-cycle use where the plates are stressed over many charge/discharge events.

The benefits:

Extended cycle life in renewable energy and stationary applications.
Reduced sulphation, which is one of the main failure modes of deep-cycle lead–acid batteries.
Improved adhesion of active material to the grid, reducing plate degradation.

The trade-offs:

Higher internal resistance reduces cranking performance and fast discharge capability, making it less suited for starter batteries.
Reduced charge acceptance compared to conventional sulphuric acid electrolyte.
Primarily beneficial in deep-cycle applications (telecom, UPS float, renewable storage), rather than automotive cranking or TPPL AGM designs like Odyssey.

Industry use

Some tubular flooded cells and stationary batteries have adopted phosphoric acid additives, but it’s less common in sealed AGM or Gel batteries. Those chemistries are already optimised for long life, and TPPL (Thin Plate Pure Lead) designs such as Odyssey focus on high cranking output rather than maximising cycle life.

👉 In short: Yes, phosphoric acid can improve cycle life, but it does so at the expense of high-current performance. That’s why it’s sometimes used in deep-cycle stationary batteries, but not in starting or TPPL AGM batteries.

12 Step Jump Start Procedure

12 Steps for Safe, Effective Jump-Starting

Jump-starting seems straightforward, but there are risks if you don’t follow the correct procedure. Sparks, incorrect connections, or failing to understand the root cause of the flat battery can damage both the vehicle and the jump starter itself. Here’s a simple step-by-step process to keep yourself and your equipment safe.

1. Safety first

Always wear eye protection and remove rings or jewellery. Any metal object can short out across the terminals and cause serious burns.

2. Check why the battery is flat

Before connecting, ask: is there a drain on the battery (lights left on, parasitic loads, or short trips)? If the battery is simply low, it might recover once charged. If it’s failed, even a jump-start won’t help.

3. Confirm your jump starter is rated correctly

Most vehicle batteries are 12V, but check that the unit is suitable before use.

4. Prepare the vehicle

Ignition off, transmission in Park (or Neutral for manual), and handbrake on.

5. Identify the clamps

Positive (Red +) and Negative (Black –). Double-check the markings.

6. Ensure the jump starter is OFF

If your unit has a switch, confirm it’s in the OFF position.

7. Connect the Positive clamp

Attach the Red (+) clamp to the battery positive post.

8. Connect the Negative clamp

Attach the Black (–) clamp to a clean chassis or engine ground, not directly to the battery negative.

9. Switch the unit ON

If equipped with an ON/OFF switch, only turn it on after the clamps are connected.

10. Attempt to start the engine

If it doesn’t crank within a few seconds, stop and reassess. Don’t keep trying repeatedly.

11. Remove the Negative clamp

Once the engine is running, disconnect the Negative (–) clamp from the chassis ground.

12. Remove the Positive clamp

Finally, disconnect the Positive (+) clamp from the battery.

Tip: A jump-start only gets the engine running. The battery should be tested and recharged properly afterwards. A weak or sulphated battery will often appear to “recover” temporarily, only to fail again soon after.

Our use of AI

How Element 82 Uses AI to Power Our Knowledge Base

At Element 82, we pride ourselves on delivering accurate, useful, and easy-to-understand technical support for all things DC power. Whether you're working with renewables, automotive systems, RVs, motorsport applications or aviation setups, the right advice can save time, money, and frustration.

To make sure we're always providing the best answers, we've trained an AI assistant using years of our own real-world experience, technical documents, product information, and customer Q&A. This isn't your standard AI chatbot — we've tailored it with our terminology, industry context, and the way we talk and explain things to customers in New Zealand and beyond.

We’ve uploaded and fine-tuned it with content from hundreds of articles, datasheets, manuals, and support tickets to ensure that when we use it, it understands both the purpose and the practical application behind every answer. It’s not just about theory — it’s about helping people find the root cause of an issue and get the right solution.

Every new article on our website is now written with the help of this AI agent. It helps ensure consistency across our content, while still leaving the final words and real-world insights to us. Shown by the fact we just removed a whole bunch of AI waffle out right here. AI thinks of itself as the only way forward, we see it as a tool.

We're using technology to scale our knowledge, not replace it. The AI doesn't know what we don’t teach it — but thanks to the depth of our content and experience, it's now a powerful tool for delivering even better support.