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Battery, Westco, MX5 Mk1/2/2.5

SKU: 12V31M

We are pleased to now offer the ledgendary WestCo sealed battery for the MX 5 (and Eunos).

This battery is superior to the original Panasonic unit. It uses the very latest absorbed glass mat technology, this advanced battery has no free liquid electrolyte - unlike the Panasonic "wet gel" battery. It also has a higher 'amp hour' (31) and a higher 'cranking amp rate' (475).

Designed specifically for the MX-5, this battery is a direct replacement for the original Panasonic battery, and is also 30% more powerfull with a cranking rate of 475 amps.

The main features are:

Sealed and maintenance free
Absorbed Glass Mat construction, not a comventional 'flooded' battery
Liquid-free, no gassing and zero terminal corrosion
Direct replacement for the factory Mazda MX-5/Eunos battery (no modifications)
Quick and simple to install
OEM correct polarity
Venting attachments for proper venting hook up
Proper channel for factory mounting bracket
2 years warranty

Size: L-197mm W-130mm H-170mm H with terminal 178mm

Fits all Mk1, Mk2 & 2.5 models, 1989>2005.

Care Instructions, Click Here

Battery Charger designed specifically for Gel and Glass Mat batteries

We would also highly recommend the use of a battery cut off switch if your car is not used on a regular basis.

Please Note: Due to airline regulations concerning the transport of dangerous goods, we are unable to send these batteries outside of Europe by air. If you are in any doubt as to whether you are affected by this, please contact us before placing your order. 


Based on 84 reviews

Hans Kleinsman
Bought to replace 16 year old original battery. Same use as the old one: intermittent, disconnect after every journey (pretty long ones) but it just struggles to hold charge. Great door stop at the ripe old age of 3 years
31/03/2022 12:17:06
Robert Byrne
Bought this battery dec 17Kept going flat have just had it tested and was told was not holding charge so on the lookout for better quality and longer warranty
17/05/2020 12:16:06
Stephen Heginbotham
I bought this battery to replace an original which was 13 years old and getting tired. This new one has been a nightmare. It just won't hold its charge. Followed all the instructions, disconnected after every journey, on trickle charger, but one journey and it's flat, AGAIN. The worst battery I've ever owned in fifty years of driving and 25 cars.
24/03/2019 12:16:09
Simon Moseley
This is my third Westco battery since owning the car 18 years. the first two were great this last one is three years old exactly and died a few times! I have charged it up and got the alternator tested all ok. If i leave the car longer than 3 days It wont even turn over.
24/08/2018 12:16:11
Norman Hughes
Very disappointing. After scouring every aftermarket battery supplier (all claiming to offer an MX5 battery but none even close to the correct physical dimension to fit) I finally bit the bullet and bought this one. I cannot comment on life or charge holding but, although claiming to be the right size, it is a very poor fit in my Mk 2.5. The battery clamp sits too high (there is now a gap of around 20mm between the clamp and boot floor) and the hardboard cover doesn't lie properly.I'm beginning to wish I'd just bought a Panasonic replacement as although the one I took out was "tired" it was the original and still working after 10+ years!
29/07/2016 12:16:17
Tibor Beetles
Lasted just under 5 years of light use, maintained over the winter in an optimate trickle charger. Not bad, but I have replaced with a Panasonic as they are now priced the same and the Panasonic is reported to be more durable with OEM units lasting 10+ years. It also fits the standard battery clamps better.
12/05/2016 12:16:17
A really poor product, my first replacement failed to hold a charge on trickle charge, was just within the guarantee period, MX5 parts changed it after being told they would test it first but stated initially there couldnt be a problem. Exchanged it after testing but stated I could not claim further on the warranty. Replacement now fails to hold charge. These batteries seem to hate winters and even with a trickle charge, fail around the time the guarantee runs out. Not a happy customer.
14/02/2016 12:16:18
Steven lyons
Original Panasonic lasted 13 years this ones only lasted 3 years ..Bought an Expensive Optimax charger the first time it failed but it couldn't charge it to more than 60 to 80%, now it goes dead after 3 days in the car.Get a Panasonic ,hopefully they're still the same design and as good as the original battery.
21/01/2016 12:16:18
Lloyd West
The battery was delivered the next day Well done! fitted it to my car - tried to start the car battery was flat. Luckily if have the optimate charger for this type of battery. Not to impressed at this time I\'ll keep you posted.Editors Note: Sorry to hear you have had problems with this. A member of the sales team will be in touch soon to see what we can do to help.
15/05/2015 12:16:20
Tony Griffiths
No more. I've gone through 2 of these and even bought a specific trickle charger (costing £100!)Went away out of country for 3 weeks, and didnt want to leave charger connected. Tried to start car, and couldnt get even the starter click. Put the expensive charger back on it, and zilch. Battery completely shot - below the theshold voltafe . So it's chucked on the floor awaiting trip to the tip. Not spending out anymore on one of these. Trying a Bosch. Half the price
15/05/2015 12:16:20

Delivery Information - MX5 Parts

We understand that its really important for you to receive your goods in a timely fashion and for a competitive price. To ensure that we can deliver this we have developed a strategic partnership with both the Royal Mail and our courier partner, Think Worldwide.

At the present time, we only offer one delivery option ‘our carrier’. We will dispatch your goods with the most suitable carrier, for main land UK deliveries this is normally Royal Mail 1st class for packages weighing under 2kg and Think Worldwide for those that are over.

Our delivery charges are based on the weight of the consignment and the destination address. For UK mainland deliveries they start at £2.95 for a package weighing under 200g and rise to a MAXIMUM of £9.95 for a package weighing 2kg or over (EXCEPT very large bulky items that have an additional shipping surcharge added). The exact delivery cost will be clearly displayed at checkout.

Delivery times are estimated at 1-3 working days by Royal Mail, and 1-2 working days by Think Worldwide for mainland UK addresses. If you order before 3pm, Monday to Friday, we will dispatch the same day. If you order after 3pm, we will try to dispatch the same day, but if we cant it will be the next working day. Items ordered after 3pm Friday or over a weekend will be dispatched Monday. Items dispatched on Friday are for delivery the following week. Items ordered over a Bank Holiday will be dispatched the next working day. MX5parts is constantly updated to keep pace with changes in our stock but demand is high and we occasionally run out of popular items. If we have run out of stock and can’t dispatch your order the next working day, we’ll email or phone you with a revised dispatch date. You can then either accept the revised dispatch date or cancel the order, as you wish. Please note, shipping times are an estimate, and can not be guaranteed. Please note that during special offer periods, dispatch of your order may be delayed slightly due to high a volume of orders.

A signature is required for ALL orders delivered by Think Worldwide. Someone must be at your delivery address to sign for your parcel between 8am and 6pm on a working day. Please send it somewhere it can be reliably signed for, like your place of work, a neighbour, or perhaps your grans. We can (but we don’t like to) ask the courier to leave your parcel without a signature. If we do this, it will be YOUR responsibility if the parcel is lost or damaged. If you want it left, you need to give us your express instructions in the ‘additional information’ box at the end of the checkout process. It would be helpful if you could also indicate exactly where the package should be left.

If you need to change your delivery address, for any packages that have been dispatched with Think Worldwide, there will be an additional charge of £9.95 if the package has already been dispatched.

Please remember, even with Royal Mail deliveries, that any items which are too large to fit through your letter box will need someone to be available to receive the delivery. If the item cannot be delivered, you will be carded and given the option of either a re-delivery or you can collect your parcel from your local post office depot.

Orders sent to countries outside the UK will be sent VAT free, however please note that on all international shipments, the recipient is responsible for any local VAT, import duty and other clearance fees that may be charged.

For further information please email:

We NOW deliver to the following countries:

Baleares, Spain
British Virgin Islands
Burkina Faso
Canary Islands
Cayman Islands
Channel Islands
Costa Rica
Czech Republic
Dominican Republic
El Salvador
France (Mainland Only)
French Guiana
Hong Kong
Marshall Islands
New Caledonia
New Zealand
Papua New Guinea
Portugal (Mainland Only)
Puerto Rico
Saint Vincent And The Grenadines
San Marino
Saudi Arabia
South Africa
Spain (Mainland Only)
Sri Lanka
St Lucia
Syrian Arab Republic
Taiwan, Province of China
Trinidad And Tobago
United Arab Emirates
United Kingdom
United States

Our Guarantee - MX5 Parts

We guarantee that you’ll be satisfied with mx5parts!

We are an independant, family company, run by a dedicated team. We aim to be the kind of company that we’d like to deal with if we were you. You have our absolute commitment as fellow MX-5 owners, car nuts, internet users and hard-working people that you’ll be satisfied with mx5parts. If you’re not, let us know and we’ll sort it out!

We guarantee “always fair prices”

MX5parts maintains an everyday savings pricing policy. We watch other retailers closely and maintain competitive pricing. The internet being the beast it is means that any Tom, Dick or Henrietta can set up a website in their back room and charge bargain basement/off the back of a lorry (guv) prices. Often they will have no stock, no returns policy, questionable security, no guarantees and of course poor customer service. MX5parts strives to be open and honest, so we will never inflate our prices to set up an artificial ‘sale’ (a common – and illegal – retail practice).

It is inevitable in an open market like the internet that there will be some individuals selling some items cheaper than we do, and some selling them for more than we do, just as in the high street. We take great pride in offering a fast, efficient, friendly and secure shopping experience, with great products at fair prices. We encourage our customers to shop around, but are very pleased to welcome them back again and again.

We guarantee to despatch your order when we say we will

If you order before 3pm, Monday to Friday and we have your items in stock , we’ll despatch the same day . If you order after 3pm, we’ll still try to despatch that day but, if we can’t, we’ll despatch the following day. Items ordered after 3pm Friday or over a weekend will be despatched Monday. Items despatched on Friday are for delivery the following week. Items ordered over a Bank Holiday will be despatched the next working day. MX5parts is constantly updated to keep pace with changes in our stock but demand is high and we occasionally run out of popular items. If we have run out of stock and can’t despatch your order the next working day, we’ll email or phone you with a revised despatch date. You can then either accept the revised dispatch date or cancel the order, as you wish. Please note that during special offer periods, dispatch of your order may be delayed slightly due to high a volume of orders.

We guarantee to replace any goods which aren’t suitable

We guarantee to accept back any goods that you do not want, are not suitable, have changed your mind about, infact, for ANY reason, provided the goods reach us within 30 days of dispatch from us, in their original condition and packaging. Please tell us why you are returning the items, just for our records. The original purchase price of the goods will be refunded on to the card that was used for their purchase. Sorry, but we can not refund the carriage costs.

We guarantee to sort out any problem with your order

Just contact us if you have any problems with an order from mx5parts. We’ll tell you exactly what steps we’re going to take to rectify the problem.

We guarantee full warranty support on all items

Just contact us if you have a warranty problem. All goods supplied by mx5parts are from official sources and are covered by the normal manufacturers warranty.

We guarantee that we will only charge your credit/switch card when your goods are dispatched

This is your right under UK law and, if we do anything else, it’s illegal!

(Please note: This doesn’t apply however if you have chosen to pay via PayPal. Due to the way PayPal works, you are effectively sending the money to us rather than us asking for it so in this instance we will have received payment at the time the order was placed and not when it is ready for dispatch).

We guarantee that we won’t pass your email details on to anyone else

Absolutely not. All your details are treated as strictly confidential. We’re internet users, too, and we know how annoying unsolicited email can be. We wouldn’t risk annoying you by being the cause of it.

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