Moss Miata
Westco Miata Battery

Westco 2nd Generation Battery

[10/14/2008] Reviewed by: John Polashock -

Applicable to: '90 - '97 1.6 liter

Westco 2nd Generation Miata battery.

The original Panasonic battery lasted 13 years in my 1993 LE. Purchased the Westco battery about 1.5 ears ago from MM Miata. Cost about $100. My car is a daily driver and generally well-cared for. The Westco battery failed this morning without warning and would not hold a charge. Needing a replacement, I found one made specifically for the Miata from Advance Auto Parts with a two year full replacement and a ten year pro-rated warranty for about the same price as the Westco. Needless to say, I would not recommend the Westco.

Under 5 minutes to remove

WestCo battery

[6/25/2008] Reviewed by: Patrick Inouye -

Applicable to: '99-'05 1.8 liter

Replacement gel cell battery.

Excellent. However, their Website listed the battery at $99, yet it appeared in my shopping cart for $125. I emailed them and they said it was a pricing mistake. I think they should've honored the $99 price since I called the matter to their attention, but instead bought it elsewhere for less.

I've bought three WestCo batteries over the years, each for different Miatas that still had their factory Panasonic batteries. No problems with cranking amps. My first WestCo battery had the polarity poles backwards, but the other two were correct for a Miata. The breather tube was in a slightly different orientation, but simply removing the hose completely and installing it backwards fixed the problem.

Under 30 minutes to remove completely

Westco Battery

[1/3/2008] Reviewed by: Ken Neff -

Applicable to: '90 - '97 1.6 liter 1.8 liter

Replacement battery

I installed this in my 1992 about seven years ago. It fit well and I have had no problems with it. 3 months ago, my alternator/water pump belt broke while driving home. I was able to nurse the car to a highway exit where I called for a tow. Needless to say, the battery was not charged enough to restart the car after I replaced the belt. One jump and a 20 minute drive were all it took to recharge. A month later, replaced belt started slipping (seems I did not lock the alternator tension bolt and it fell out). I drove about 20 miles on mostly battery power. By the time I got home, the lights would not work. After letting the car sit for a few weeks, the battery went dead altogether. I had it charged and have had no problems since.

I recommend this battery highly.

Under 5 minutes to remove

Westco Miata Battery

[6/21/2006] Reviewed by: Julie Mitchell -

Applicable to: '90 - '97 1.8 liter

Do not buy this if you live in a cold climate and drive infrequently. After having the Mazda battery last for *seven* years, this one did not last even one winter. On top of your $89.95, don't forget to buy a $69.95 jump start kit. Once your battery is dead a couple of times, it will no longer hold a charge, even if you drive to Chicago and back. The kicker: when you call WestCo to ask about a warranty (totally standard for batteies), they won't give you a straight answer. Turns out their "warranty" is negotiated with the vendors, and is usually 12 months. I'm going back to the Mazda battery. Assuming it lasts even three years in the cold weather, it still averages out to be cheaper than the WestCo. And, the Mazda battery is fully warrantied for three years and has prorated warranty for an additional three years.


Under 5 minutes to remove

Response from Jason Smith at Westco:

I am employed by MK (Westco) Battery and have worked there for 11 years. Prior to that I worked for Interstate Batteries for 6 years. I just wanted to respond to a couple of the negative reviews on this forum. We sell a quality product that was the first sealed battery ever for the Miata and stand behind the warranty 100%. Sometimes batteries being mass manufactured fail prematurely. 2-3% of all batteries regardless of the manufacturer fail early. We are well within what is perceived as normal in the industry. The Miata does utilize a small battery relative to normal car batteries as well as being a car that is typically driven infrequently. These factors can contribute to early battery demise if proper maintenance on the battery is not performed. It is imperative if your battery sits for extended periods of time that it be monitored with a small automatic battery charger. If not, you can shorten the battery life. If you have any questions concerning this or any other battery questions, feel free to call us at 800 372-9253 or you can certainly e-mail me at Thanks for your business and have a great day!


[5/16/2006] Reviewed by: Ken -

Applicable to: '90 - '97 '99 + 1.6 liter 1.8 liter

WestCo Battery for Miata

Fits inside the original tray, a little taller. Terminal are in the correct position. Bought this battery to replace the Org Panisonic Battery 215K mi 1990 Miata(In service for 12yr). Should have asked about the Westco warranty because it's just 4 yrs (48mo)!! The Westco battery was installed on Jan 2002; started to act-up Jan-Feb 2006. Contacted Westco about problem with battery, Sorry out of warranty. Big rip-off!! lasted just over 4yr-30k mi, good engineering calculation of expected life of WestCo battery to avoid returns!! AutoZone has a identical battery with 8yr warranty $79.99+core. The Org. Panisonic Battery is Gel based (similar to Optima) is the best deal going compared to buying Four Westco battery $89.00.

How much do you trust a Co that don't advertise warranty mo coverage? Shipping a battery is risky, maybe the UPS driver dropped or damaged it before delivery. Next time OEM or Optima Gel!!!

Under 5 minutes to remove

WestCo Battery

[12/14/2005] Reviewed by: Brett Giza -

Applicable to: '99 +

Sealed Battery

Dropped it in on December 2nd and the next day it snowed. Haven't thought about it since. $89.95 with Free shipping. Well worth the extra 10 bucks over the replacement battery that Auto-Zone carries. I have heard great reviews about the WestCo battery, so I went with that.

It was posted as having the exact hook-up as OEM. Only problem I had was with the breather tube. OEM sets up on the sides of the battery. WestCo has coonectors on the front of the battery. I convinced the tube that it wanted to connect to the WestCo.

Under 5 minutes to remove

[12/12/2002] Reviewed by: Anonymous

Applicable to: '90 - '97

12 volt sealed battery

This battery is great.

Factory Mazda battery died so I needed a new one. Saw all of the positive comments on Westco batteries and decided to try one at $84.95 about $25 cheaper than a new Mada battery. 2nd generation batteries are muched improved apparently over the first generation. Polarity poles in the correct location now and only minor issue I had with installation was the breather tubes. Factory uses a square hole and Westco uses a round hole. Easy fix, simple cut off the very top of the hose and you are left with the round portion that connects right to the battery. Installation was less than five minutes. The battery came well packaged and was fully charged. Started right up with authority. Highly recommeded.

Under 5 minutes to remove

[4/12/2002] Reviewed by: David Wrinkle -

Applicable to: '90 - '97 1.6 liter 1.8 liter

This is the Westco Miata battery 2nd generation. (Terminals are now reversed to fit the Miata correctly)

I received my Westco battery about 3 business days after having ordering it. The battery arrived via UPS and was packed very well. As I recall, you need 10mm and 11mm wrenches to remove the old battery. After removing the cables, battery hold down, and vent tubes I swapped my 11 year old panasonic for the Westco. It is slightly smaller in length, but this isn't a problem. It still fits fine in the stock battery tray. The height of the Westco is a bit more than the stock battery and it took me a few extra minutes a struggle to get the battery hold down in place. I then secured the battery. The existing Miata vent tubes connected to the Westco just fine, as did the battery connectors. A few seconds later we are up and running with no problems.

Under 30 minutes to remove completely

[3/6/2001] Reviewed by: Mark Rosenson -

Applicable to: '90 - '97 '99 + 1.6 liter 1.8 liter

Westco replacement battery


Don't even consider buying the Mazda replacement battery! This one is better and cheaper. Ordered on Sunday, delivered on Wednesday. Fits just like the original.

Under 30 minutes to remove completely

[8/12/2000] Reviewed by John Daeschner -

Applicable to '90 - '97 1.8 liter

After market replacement battery for the Miata

I purchased the battery directly from Westco, they have a "button" on their web site,, for the Miata. Makes things fast and simple. I paid $79.95, shipping and handling are free of charge, no tax either. The battery came from Dallas - I'm 150 miles away - so I got the battery in less than 24 hours. No special shipping issues, it came UPS ground. The people at Westco were exceptionally friendly and courteous, the whole experience was a pleasure. The battery is a perfect fit, just s little shorter in length than the original but actually weighs about one pound more. The terminals are correctly oriented and the vents are actually in a better position than the factory battery. Vent hoses connected right up with out a problem. I did the whole job with a single 10mm wrench. The car started right up and much more powerfully than the five year old original. Overall, perhaps the most satisfying buying experience I've ever had, I'm totally happy.

The original Panasonic battery was a very good battery indeed. It lasted five and a half years and was driained "dead" perhaps ten times - but always came back to life. I replaced it because I could feel it getting weak and was about to take a long trip. I also feel that this mode of failure is very good, you don't just wake up one day to a dead battery, you have a little warning. What could be better than a part that warns you it is about the fail so you have time to replace it? I understand that the Panasonic battery is no longer available - too bad. It's probably worth $140 - I would have paid that amount. I hope I'm just as happy with the Westco.

Under 30 minutes to remove completely

[3/16/2000] Reviewed by Andrew Wallace -

Applicable to '90 - '97 '99 + 1.6 liter 1.8 liter

This is the new WestCo replacement battery.

It seems to be improved over what I read about the original in that

I pulled the old battery and put the new one in, took about 15 minutes (part of which was spent hunting the right size socket). The car started right up, immediately. Also some problems that I had with my audio system (a loud pop when I turned on the lights, and other less understandable times) has gone away.

I ordered it on Sunday, got it on Tuesday, and my Miata now starts every time! Yippee!

Under 5 minutes to remove

[12/15/99] Reviewed by Jac Cottrell -

New & Improved Westco Battery

Applicable to '90 - '97 '99 + 1.6 liter 1.8 liter

New stlye Westco battery

It Fits.

It Starts.

 Under 5 minutes to remove

Reviewed by: Keali'i Llantos -

Replacement battery

After years of faithful service, the factory battery finally decided to retire.

I ordered the Westco battery from Moss Motors. It arrived in a little over a week. The battery seems smaller than the stock battery. The terminals also are not positioned in the same location as the stock battery. This made connecting the wires to the terminals a bit awkward. The smaller overall battery size also meant the battery holddown clamp is a tad bigger/taller. I had to turn the bolt a few more extra turns to tightly secure it.  Finally, since this is a sealed battery, the stock overflow/pressure tubes are no longer required.  Now for the test. I hopped into the car, cranked the engine, and it fired right up.

Aside from the non-factory aspects of the Westco unit, it is a very good alternative to the stock battery.

For pictures and additional information, please visit my site at

Under 5 minutes to remove

Reviewed by: Marvin Gozum -

Replacement for the Panasonic gel battery.

Excellent replacement. Its performance exceeds the original part. It cheaper. Greater power density than the original, being slightly smaller and lighter in weight than the original part. The difference is startling.

The battery poles are in the opposite direction from the stock Miata Panasonic battery. Installed then, the battery position is reversed, placing the contacts slightly farther than the original.
This does not affect any cable placement. However, it may interfere with objects than occupy space just behind the battery, such as power antennas.

Back to Product Reviews 22 November, 2008

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