Working with lead-acid batteries

Lead-acid batteries pack a lot of power and it’s always important that we treat these things with respect. Whilst it might seem a bit over the top, we always recommend wearing eye protection and gloves whenever you’re working near batteries.

Lead-acid batteries contain sulfuric acid and produce hydrogen gas even when the vehicle is not in operation – so it is vital to always keep them in a well-ventilated environment – and ensure that no sparks, flames or cigarettes ever go near it. Most batteries have integrated flame arrestors which prevent an external flame from passing through and igniting the battery, but caution still needs to be taken.

We also need to make sure that we aren’t wearing any jewellery on our hands, arms or around our neck – as these items pose a huge safety risk in the event of an accidental short circuit. Imagine if you’re using a spanner to undo the terminal and you accidentally create a short circuit through the spanner and through your ring. This massive flow of current could potentially heat the spanner and your ring up to hundreds of degrees in just a fraction of a second. So don’t take the risk – remove these items and pop on a set of gloves.

If you need to charge a lead-acid battery, it is important to use a correctly sized battery charger – and you can work that out by calculating 10% of the battery’s Ah rating. For a 60Ah battery, a 6-amp charger would be perfect. We’ve got an entire video on that which you can check out – but the takeaway here is higher amp chargers can overheat and permanently damage your battery during the charging process. This can boil the electrolyte and accelerate the release of hydrogen gas – reinforcing the importance of a well ventilated environment.

Back in the old days, batteries had vent caps which you could remove to top up electrolyte. But most batteries today are sealed maintenance free – and even though this one looks like it might have a part here you can pop off – I can assure you it is sealed for life. Attempting to remove the top from an SMF battery will permanently damage it and should not be attempted at any time.

Even though the lids are permanently sealed, if you handle these batteries roughly there is a chance that the sulphuric acid inside can escape. For example, if you accidentally dropped the battery on concrete, or if you tipped it sideways or upside-down for extended periods of time.

Battery acid - or electrolyte as we call it - is serious stuff. It can destroy clothing and burn your skin, so extreme caution must be used when handling these things. If electrolyte somehow splashes in your eye, force the eye open and flood it with clean, cool water for at least 15 minutes – and get prompt medical attention. If electrolyte is taken internally, drink large quantities of water or milk and do not induce vomiting. Again, get prompt medical attention.

Baking soda can be used to neutralise any electrolyte that has been spilt in a vehicle or in the workshop, before the area is rinsed with water.

Sometimes safety tips like these can seem a little heavy-handed. But accidents are just that – accidents. They’re things you didn’t think could or would happen. So by taking a few simple precautions, you can keep yourself and others around you safe.