Due to the current Coronavirus threat, many of us are taking government advice by working from home or self-isolating where needed. This unprecedented time is worrying for us all. We have prepared a few points to consider so that when you come out of isolation you don’t get into your car or onto your bike to find that you have a flat battery, making a tough situation even more difficult.
The Basics
Your battery has a finite amount of charge in it, known as the capacity. When you start your car or use the onboard electronics you are taking from the stored capacity. So why does your battery not run out of charge? That’s because your car has a component on board called an alternator, which uses power from the engine to recharge your battery back to its full capacity.
The Problem
When your car or bike is stood without use it continues to slowly take charge from the battery to power items such as the alarm and onboard computer etc. Normally you would use your vehicle most days, or every few days at least, so as you drive you’re replacing the lost charge. However, at the moment we do not know for how long some of us may be indoors and unable to regularly use our vehicles or motorcycles again. So if the period is prolonged, the capacity in the battery may well fall well below the capacity required to start the vehicle. This is when you’ll need to call a breakdown service to start your vehicle for you.
Further to this – and to make matters worse – when a battery is left in a discharged state, a chemical reaction occurs and a coating begins to build on the internal plates. This reaction is called sulfation and makes the battery resistant to taking a future charge. Symptoms of this are easy to detect; the battery will get warm during charging and a smell of rotten eggs is often emitted. If this is allowed to build for too long the battery will become unserviceable and will need replacing. This is not covered by any battery warranty as it is not a manufacturing defect.
The Solution
The ultimate solution is regular use of the vehicle, but under current conditions, unless you have a sprawling country estate at your disposal that’s not going to be possible.
The next ideal thing to do would be charging your battery every two weeks using a dedicated car battery charger. If you have a garage or driveway, you can use any car battery charger, such as those from CTEK and NOCO. Read the instructions carefully and connect as described. Many people opt to leave the charger connected to the battery for long periods where the charger state this is possible.
If you have no driveway, the alternative is to take the battery from the vehicle and recharge it indoors.
Questions and Answers
Q: Why would I need to look after my battery? It’s maintenance-free!
A: Maintenance-free batteries are confusingly named – they do require charge maintenance – you simply don’t have to monitor the electrolyte levels as you would have had to do a few years ago.
Q: Will running my engine for 5 minutes maintain charge?
A: No – this won’t help and in many cases this can make things worse! Charging a battery from discharged to charged takes around 10 hours. By starting your engine you will be taking a large chunk of charge from the battery and over five minutes may not replace all that you have taken out. If you were to try this method you’d need to leave the engine running for a couple of hours. IN a confined space this would be dangerous, and the environmental impact wouldn’t be great either.
Question:
Will a trickle charge unit work if you leave on permanently.
How about connecting a solar panel ?
Inside the car, it wont be the most efficient it can be, but it only needs to put out more than the car is taking for a net charge.
Do you know, can you recommend one?
Cheers, will forward on to group
Good advice. I have a CTek charger which I use fairly regularly as I do not drive every day so need to maintain my car’s battery charge level. Plus my car is right outside my house on a driveway so is easy to get to with the mains lead.
I’m sure there will be many people who, once they are allowed out again, will find their vehicle’s battery is dead to the world so need to take heed if they can.
Hi Norman, in many cases that will be ideal. Check the manual for the specific charger you’re using for guidance and to ensure it will automatically turn off once the battery is fully charged, then recommence when required. Most modern ones do.
That will definitely help Michael. Ring Automotive produce some good ones. Sadly we don’t supply them buy you should be able to source online. Go for the largest you can fit/afford.
Is It a good idea to disconnect the battery’s earth terminal when my car is not in use for a while then reconnect it when I need to drive again ?
Thank you,
Excellent tips for keeping a car battery charged.
That’s a good idea – it will certainly prevent the vehicle from draining it. However, there is still a natural self-discharge that will occur, so be aware that this isn’t ideal, but far better than doing nothing.
Good advice for car batteries .
What about caravan leisure batteries, the caravan charger, caravans with solar panels with 100w for example?
The article says “Many people opt to leave the charger connected to the battery for long periods where the charger state this is possible.”
Some people may think they can leave any battery on charge for weeks using whatever charger they have on hand. To avoid causing damage, what about just saying to charge it every fortnight?
where can you get a ctek charger
The same applied to Caravan Batteries, but to be honest most people will already be doing this during the Winter months. If not, they should be!
Hi ‘a forster’, the ideal CTEK charger is this one: https://www.tayna.co.uk/battery-chargers/car/mxs5-0/.
New start/stop battery is holding up well even though I only drive about 10 miles a day. Despite being a petrol head I didn’t know that many cars are now fitted with “smart” alternators which only actually charge the battery on the over run rather than simply always charging as the engine is running. Apparently it is all in the name of emission control. Have you ever published anything on smart alternators and the revised driving techniques that could be used to minimise battery drain?
Thanks for the info so far. Very informative.
Hi Noel, no we haven’t – great idea though. We’ll get onto that as soon as things get back to ‘normal’!
Can I charge the battery on the by just disconnecting the negative terminal?
Yes in most cases. Many cars/chargers will allow it to be charged while connected to the car too.