Coronavirus: Will trickle charging or jump-starting your car's battery invalidate the warranty?

Will jump-starting your car invalidate the manufacturer's warranty? What are the implications of attaching a trickle charger to the battery? 

HonestJohn.co.uk has received thousands of reader questions via Ask HJ regarding battery care during the coronavirus lockdown. The general advice is to read the owner's manual for the vehicle and follow the official guidance for trickle charging or jump-starting. But even if you do this, what are the implications for the vehicle's warranty? 

HonestJohn.co.uk has contacted every carmaker in the UK to uncover the manufacturer-specific advice on car charging and jump-starting.

Manufacturer Response 
Alfa Romeo Jump-starting a car will not invalidate the warranty, however, customers should always refer to the handbook which will give them guidance on how to do this safely and correctly.
Audi

The warranty on the battery will not be voided if the owner follows the advice specific to their vehicle which is available in their handbook.

If a customer does not have a handbook and the opportunity to buy one is restricted (Covid lockdown), then the Audi Customer Service Centre should be able to help with guidance for their specific car.

BMW

Awaiting response

Citroen

If the instructions are followed in the handbooks with regards to jump-starting, no damage will occur. Trickle charging is safe to carry out, as long as the instructions are followed for the unit being used.

If the user does not follow the guidance and damages the vehicle, this will not be covered.

Dacia The warranty will not be invalidated if a customer chooses to trickle charge or jump start their vehicle.
DS 

If the instructions are followed in the handbooks with regards to jump-starting, no damage will occur. Trickle charging is safe to carry out as long as the instructions are followed for the unit being used.

If the user does not follow the guidance and damages the vehicle, this will not be covered.

Fiat Jump-starting a car will not invalidate the warranty, however, customers should always refer to the handbook which will give them guidance on how to do this safely and correctly.
Ford

Awaiting response

Honda

Customers can trickle charge the 12v batteries in their cars. Though they have to completely remove the connection to the car before doing so. 

They cannot trickle charge the main battery in a Honda hybrid – that is powered by the car and will never go below 20% charge anyway.

We are awaiting response in regards to jump-starting.

Hyundai

Where relevant, jump-start instructions are given in the owners handbook. Some of our hybrid and electric vehicles have a 12v reset function, so don’t need to be jump-started.

As for trickle charging, there is nothing in the warranty to prevent this and provided the relevant instructions on the charger are followed, I’m not sure how any damage could be caused. The only real danger is the customer connecting the positive and negative terminals incorrectly or an incorrect voltage being used which could cause damage to the electrical system, however a good quality trickle charger should have its own protection systems to prevent this.

Jaguar

Awaiting response

Jeep Jump-starting a car will not invalidate the warranty, however, customers should always refer to the handbook which will give them guidance on how to do this safely and correctly.
Kia Awaiting response
Land Rover

Awaiting response

Lexus The official guidance would be referring to the vehicle handbook for safe operation.
Mazda

"There is no specific warranty invalidation clause for jump starting or trickle charging. However, should a Mazda vehicle require jump starting with either a boost pack or by utilising the battery from another vehicle, this should be done in strict accordance with the information shown in the owner’s manual. If this guidance is not followed and electrical components are subsequently damaged as a result, then these will not be covered by our Manufacturer’s Warranty.

Whilst we recognise that there are many types of battery charger available designed to keep the battery voltage topped up; Mazda do not recommend any form of battery charger be connected to the vehicle battery and left unattended. This includes the use of trickle chargers, as a fault could occur with either the charger or the vehicle battery which would increase the risk of fire / explosion. Mazda recommend starting your engine on a regular basis and have it running for several minutes to prevent the battery voltage from depleting completely, as this can also prevent the failure / corruption of other electrical systems on the vehicle."

Volvo also told us that a 'How to look after your battery' film  will be shared on Mazda UK’s customer channels by the week commencing 20 April, which will assist customers concerned about cars being static for sustained periods of time in the current lockdown. Customer relations team are working remotely to answer any questions/calls from Mazda owners, too.

A specific COVID-19 Q&A page for customers can be found here.

Mercedes-Benz Awaiting response
MG Battery jump starting – Owners are advised to always refer to the owners section on the MG website and to follow the simple step-by-step instructions. By not doing this, the warranty may be invalidated.

Battery charging – Trickle charging units can be used on MG cars but we highly recommend that owners follow the supplier’s instructions which should be read and followed to the letter.

MINI

Awaiting response

Mitsubishi

Mitsubishi has a specific section of the website dedicated to Caring for a hybrid or electric car during coronavirus. You can find that here.

Nissan

Cars under warranty are covered by breakdown assistance (provided by the RAC) including the event of flat battery.

For NHS & Key Workers we have extended this roadside assistance programme to cars in or out of warranty during this ‘lockdown’ period and are providing this service to them free of charge. This cover will include homestart, roadside repair and recovery to home or the nearest Nissan dealership still able to stay open for aftersales service. In addition, Nissan will also prioritise free-of-charge courtesy cars for key workers should their vehicle need to be repaired at a dealership.

As for jump-starting a battery, the procedure to carry out a jump start correctly is highlighted in the Nissan owner’s manual. Battery Care Guidance if vehicle is not to be used/stored (30+ days) is listed in section 8 Owners Handbook.

Peugeot If the instructions are followed in the handbooks with regards to jump-starting, no damage will occur. Trickle charging is safe to carry out, as long as the instructions are followed for the unit being used.

If the user does not follow the guidance and damages the vehicle, this will not be covered.

Porsche

"Our advice regarding trickle charging and jump starting is always to consult the manual in the first instance – it has vehicle-specific guidance on both – and failing that to contact their Porsche Centre by email or our Customer Assistance team by phone or email for guidance.

Our advice for owners who don’t have access to a suitable trickle charger is to start the car once a week and leave it running for 15 minutes. For our plug-in hybrids, the recommendation is to leave them plugged into the charger, which will also condition the 12v battery. All our hybrid chargers have a 3-pin connector for domestic plugs.

Our more recent cars also have a protective mode which shuts down non-essential functions to safeguard the battery when it senses the voltage getting low, so this in itself should give peace of mind to those owners of cars still under the new car warranty."

Renault The warranty will not be invalidated if a customer chooses to trickle charge or jump-start their vehicle.
SEAT

While we’d generally advise customers not to trickle charge their vehicles, however, these are certainly unusual times. Our customer helplines remain open, as well as the live chat feature on www.seat.co.uk, so in the first instance we’d suggest a customer contact SEAT customer services, or their local retailer, for guidance on their individual case.

A vehicle can be trickle charged but it’s important to note that our vehicles use lithium-ion batteries so if a customer wishes to utilise a smart charger then it must be compatible for this battery type, and it must not be rated more than 32A with a capacity of 250Ah. 

A customer trickle charging their vehicle will not invalidate their warranty.

Skoda

"In the event of a Breakdown at Home, the customer should contact ŠKODA Roadside Assistance who will attend to either repair or recover the Vehicle. SKODA Roadside Assistance is included in the SKODA Approved warranty."

Smart Awaiting response
SsangYong

"There is nothing that technically advises the customer not to jump start or trickle charge our vehicles although we would advise trickle charge over jump starting. Note this has no adverse effect on the warranty."

Subaru

Awaiting response

Suzuki

The Suzuki website advises that if your car isn't being used: Once a month, we recommend that you run the engine for 30 mins with the headlights on. This will help to ensure that your battery (and hybrid battery if fitted) stays topped up.

Toyota

The official guidance would be referring to the vehicle handbook for safe operation.

Toyota tells us that more specific advice regarding hybrids will be up on the website in the form of a blog post soon.

Toyota's website also says: Toyota GB would like to reassure you that for the foreseeable future we intend to take a flexible and sympathetic approach to any service schedule or warranty issues.

Vauxhall

Our simple advice to owners would be to refer to their owner’s manuals. If these recommendations are observed, any warranty in place would be honoured.

Volkswagen 

Awaiting response

Volvo

"In order to maintain the starter battery in good condition, it is recommended that there is at least 15 minutes driving/week or that the battery is connected to a battery charger with automatic trickle charging. A starter battery that is kept fully charged has a maximum service life.

As regards jump starting, again, we don’t discourage this if it’s required, but – again from the handbook:

  • 48v support battery must never be used for jump starting
  • External electrical equipment must not be connected to the 48v battery under any circumstances
  • The 48v battery may only be serviced and replaced by a workshop - an authorised Volvo workshop is recommended"
Ask HJ

Can trickle chargers be used with stop-start engines?

Due to the coronavirus, I want to ensure that my car battery stays charged. The advice seems to be to use a trickle charger. I've noticed that many trickle chargers are not suitable for stop-start engines. If this is correct, what sort of charger would you recommend?
You need a trickle charger that works with AGM batteries. This should do the trick: https://amzn.to/39GTA0s
Answered by Andrew Brady
More Questions
Ask HJ

How often should a trickle charger be used on a car that's only used once weekly?

I only use my car once a week. How often should I be charging the battery?
The more you can expose a lead acid battery to charge the longer you will extend its life. We spoke to CTEK who confirmed this, saying, 'Any chance you get to charge you should do it – don’t worry about overcharging as the charger has set trigger levels based on voltage, charge acceptance (amperage) and time, if your battery is charged regularly it will pass through the charging stages very quickly and settle in long term maintenance.'
Answered by Keith Moody
More Questions
 

Ask Honest John

Value my car