Go48

Thanks for that. Obviously, your e-mail was more effective than mine.

Good luck with getting Mazda to give you the new battery. There is no indication that Mazda intends to replace the original Yuasa batteries with the MTP-35 under a recall or warranty. However, anything is possible and if you can convince a dealer that the original battery was "defective" you may have a chance.

There's little doubt that the 50D20L does not provide much margin in the cold areas of the US, particularly if one is attempting to do the de-choking procedure. That's why Mazda installed a more capable battery in the Canadian cars. In the final analysis, my guess is that they would have been better off going with the more capable battery in the US cars and possibly avoiding some of the owners trips to their dealers for flooding problems.

MX6_2_RX8

I work as an electrical engineer and sent the request from my work email so they probably figured I was asking because I wanted to use their product. Whatever works.

My car is about 45 days old and I feel lucky if the car starts after few days in the cold (because some days it doesn't). They are giving me a new battery!

Go48

Amen to that!

That's great! Make sure it's the MTP-35 and not the MT-35. I'm sure you noted the confusion that Interstate had in deliver the batteries to Trussville. Let us know how it does in the Maine cold. Unfortunately, it doesn't get as cold here in S. PA, and I haven't had starting problems, so I will be paying for mine.

mitchfried

Looks like the stock Yuasa 50D20L at about 23 pounds (http://www.dcpowersys.com.tw/care.htm) is much lighter than the MTP-35. Maybe the Optima 51R at 26 pounds would be a better choice for us Florida boys with lots of audio equipment?

Go48

Like "they" say, ya don't get something for nothing. More lead, more weight. More substantial case, more weight. And so on. Personally, the extra weight is not an issue with me, but to each his/her own.

One thing that's not clear on the table at that site is whether or not that is dry weight or wet weight (i.e., w/acid). Some sites specifically state dry weight, others are not specific. The only way to know for sure would be to remove the OEM battery and weight it.

In any case, if you go with the Optima, make sure the battery posts are in the same position as the original. Otherwise you may be doing a cluge, as some have done, to get the cables to reach the posts. Also because of the design of the battery box, the size of the battery is critical to fitment and, more importantly to maintaining the flow of air around the battery, so keep that in mind, too (see the recent TSB on the "new" replacement battery if you haven't seen it).

BTW, the MT-35, with 550CCA, is about 3 lbs less than the MTP-35 according to the Interstate specs. It's also cheaper

rx8cited

WTF, I wonder would they specify a dry weight since the battery is useless without electrolyte?

I don't recall seeing dry weight specified anywhere .... do you have a link handy?

Go48

Yeah, see the link #1 below. The 50D20L is not in this table, but one of the 3 OEM batteries, the 75D26L, is listed at 12.3kg without acid.

The 75D26L is listed on in another table on a different web site as weighing 21kg (see link #2). So you can probably conclude that the acid weighs about 9kg for that particular battery. Although this is not a Yuasa battery, it is likely built to the JIC specs.

#1 http://jw4u.com/vehicles/automobile/battery/
#2 http://www.resourcebattery.com/products_car.htm

MX6_2_RX8

I got my new battery yesterday. It was the MT-35 and was covered under warranty. I gave them the cut sheet on the MTP but that's not what I got. In any case it should be quite a bit better.

Go48

Yeah, the MT-35 should do you just fine. But if you read earlier in this thread, the response I got from Trussville you know that there was an initial mixup in the models that were shipped by Interstate to the dealers. Looks like you got one of the mis-shipped models, but it is still much better in the CCA department than the original battery and even better, it didn't cost you anything.

Do you notice any difference in starting the car? Like more rapid spinning of the rotors?

MX6_2_RX8

It turned over a little better. I was always amazed that it started before, it cranked so slow. Of course, sometimes it didn't.

Go48

Thanks. A little better doesn't really motivate me to run right out and buy a new battery, so I will probably go with the original battery for a couple of years. My car is garage-kept and I don't take it out in very cold temps anyway.

MX6_2_RX8

If it works don't fix it. I'm finding that the tires don't stick in the cold even if there isn't any snow on the road.

rx8cited

Stock tires? Yep, that's well known ........ check out the Wheel, Tires, ... forum @ https://www.rx8club.com/series-i-wheels-tires-brakes-suspension-55/

MX6_2_RX8

I just wanted to report that there have been some zero degree F days since I got the new MT-35 battery and the car cranks over much better. I’d advise anybody that thinks their battery may be on the edge to see if they can get it replaced under warranty, mine was. I think the old battery was marginal at best and they must know that. Good Luck.

Go48

Yeah, "marginal at best" is the best way to put it. Thanks for the update. I still don't understand why Mazda didn't put the same battery in the US cars as they did in the Canadian cars. They saved a few pennies initially, but I suspect they are paying for that decision big time due to all the "failed to start/flooded" visits to their dealerships.

Oh well, like "they" say: Ours is not to reason why, ours is but to do or die.

NoVa

I dont know much about car batteries so hold onto the flames, but the person that was installing the auxmod for my car said he wanted to get rid of the Stinger Power2 SP1000. He said it was intended for a Rx-8, but he wrecked it. The price is 160 installed , but Is this overkill? I was thinking of going with the optima battery like everyone in this thread has, but it seemed like a good price.

Rich

JM1FE

Shipping. Some non-sealed batteries are shipped dry. H20+H2SO4 are added later.

rx8cited

Thanks - I learned something new .

mysql101

btw, I bought the red top 35/75 and installed it in my car with the neg/pos terminals in the same position as the stock batt. the stock cables fit just fine.

I did have to cut the plastic thing that surrounds the batt a little bit, since the batt was not as tall - the battery holder that keeps it in place was being blocked by the height.

mpotenza

I have had a problem with battery replacement using 35 battery. The battery cable diameter is too large for the posts and I am unable to tighten down. Mazda wants me to by a battery from them for $200+ as they assure me the cables will fit better on the posts of their battery. Has this been a problem with anyone. In the past I have added a battery post shim

Red line envy

If the terminals are not able to tighten down then just replace them. Check your local part stores or order online.

mazdaverx7

iTrader: (6)

I agree with the above. Its likely that the terminals have been overtightened and are stretched. The terminals can be replaced with new terminals and you'll be good to go and can use your current group 35 battery.

TeamRX8

iTrader: (25)

never go back there again.

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