Robby

When I got my car almost 4yrs ago, the PO's battery was too tall- touched the underside of the hood- only prob seemed to be the mark on the underside of the hood, but I soon bought a new one anyway- my mechanic sent me to Interstate Battery & they sold me an MT47. It was smaller, &, to my pleasant surprise, LIGHTER by ~7lbs IIRC (it's ~30 or 31lbs). The obvious drawback- 590CCA- the other was in the 600's- the MT47 wore out in ~3yrs My mechanic had a new MT41 & showed me where it was listed as the recommended size for 951. I noticed right off, that it was much larger & heavier & had ~650CCA. It LOOKED to be the same size as the PO's, but, I passed on it, so don't know if it would've rubbed, etc. I went to IB- they looked up the 951- THEIR catalog listed the MT47 not 41, BUT, I didn't actually SEE them look, AND, they were about to close, so I didn't push it, etc, as it was what I had used for >3yrs, AND, since I'm a weight fanatic, I WANTED it to be right They have a 60mo warranty, so they pro-rated a discount & installed the battery for me (which I didn't expect), so I gave the wrench/salesman a few bucks for keeping my hands clean (although I had planned to do it all myself) & left. Now I'm wondering...

What size/types of batteries are other's using in their everyday driven 944's/951's, etc? Specs (CCA's), etc? Probs w/fitment? I have only ONE small 4-ch amp for extra stereo stuff- no subs, etc. BUT, I DO have Iceshark headlights & they are, unfortunately, hooked straight to the battery, instead of the alternator like they should (& soon WILL) be. And w/the AWESOME light THEY put out, I'm kind of amazed I haven't gone through SEVERAL batteries- SHOULD they wear the batt out quicker than IF they were hooked to the alt?) Any input on any of this?

Anyone try &/OR have any luck w/any lightweight batteries/DRYcells? I have some of SCC's Project RX7TT articles- a guy made them some custom dry-cells- one was only 14lbs they used a 17lb one, shaped to fit in a rear cubby of the car. But, I never heard ANYTHING about them after that, so I have NO idea how they worked in the long run- I DID talk w/the guy who made them- he said he could make me one that weighed ~18lbs w/almost 400CCAs, but that dry-cells were dif & CCA's wouldn't really matter as much, etc, & that ~350CCAs would "probably" be fine for a street 951... MAYBE(?), but I was scared to guinea-pig it myself. Anyway, I would LOVE to find a battery under the 25lb mark that would work WELL, be reliable, & LAST. Any input here?

Last: I've seen battery covers in 944's- not the little square ones that only cover ONE terminal, BUT, slightly larger ones. IIRC, they covered the whole exposed area of the battery & they kept water AWAY from it, since the 944 battery is in such a bad place by teh windshield- this MAY have been something that connected at the base of the windshield & not the battery, but... Still better, I would LOVE to move the battery to the trunk, like Euro S2's, etc... Anyway, anyone know about these covers, where I could buy one, etc...?

Thanks a lot,

944Play

CCAs, AFAIK, are just a measure of a battery's rate of delivery, not capacity. Porsche specifies batteries in amp-hours.

I have a group size 47 battery in my 944 with the positive terminal cover flap. I have been looking unsuccessfully for a full cover, and have come across these part numbers:
477-915-411A
3B1-819-422-A

GL, HTH.

89magic98

The battery is a group 40R. My battery has the number "41" listed on it.

I don't have a clearance problem. The battery has a positive terminal cover, but you should be at least 1/2" away from the bottom of the windshield. And you should also disconnect the negative battery terminal before moving the battery.

I got a replacement (Excide) at Kragen just this week, for $55. It has ~680 CCA, 84 month warranty.

You could look for the battery size here:

http://www.exide.com/batteryselector...ryselector.asp

I had an interstate battery - mine lasted 7 years, I would have bought another one if I could have found a big supplier near my house.

I also had an exide, lasted like 4 years.

-Kevin

Manning

The (factory) battery cover that was on my car is basically a black plastic cover that snapped over and covered the whole top of the battery. It is kind of, uh, simple in its design but it works. The one I have doesn't connect to anything other than the battery.

Manning

Oh yeah, everybodies favorite, Automobile Atlanta, had them in stock last I checked.

Robby

Thanks guy's!

Kevin- you wouldn't, by chance, still have that Exide OUT of the car would you? If so, would you mind throwing it on a bathroom scale? 680CCA's & a 7yr warranty sounds excellent! Also, $55- my Interstate was $65, including tax & that was AFTER the warranty discount(!)- IIRC, the first one cost me $75 + tax ~3yrs back,& again, that's w/a 5yr warranty & 590CCA's... I'd love to know why my Interstate lasted HALF the amount of time YOUR's did... Do you remember which specific Interstate you had before & whether or not it was smaller &/or lighter than the new Exide you bought, etc?

John, etc- would a "47" battery from one brand weigh the same &/or be the same size as a "47" of another brand? I'm more concerned w/weight, obviously, as long as it will fit in there w/out rubbing, etc. Thanks for the #'s- I'll check them out- could they be on the PET CD...?

Manning- that's probably what I'm talking about. But for some reason, I envision it as being a red-orange though, but that could be b/c the little terminal cover protectors are that color & are fogging my memory- it was nothing technical at all though- VERY simple little cover- I'd like to find something a little tougher- I don't like the idea of someone being able to get to my battery as easily as they can w/these cars, nor the elements... Anyone in hte mood to make a custom, really lightweight cover of some sort that would go across the bottom of the windshiled & be able to mount (to something?) easily at multiple points, out of carbon fibre or aluminum or something? ANYONE...?

Thanks a lot,

89magic98

Robby,

Too bad you didn't ask yesterday - I did have it out. I would take the bathroom scale to the auto-parts store.

I think the battery listed on the Interstate site (MT-47) for our cars is the WRONG size. I think the battery selector should choose the MTP-40R instead.

BCI #
Interstate Type
CCA*
CA/MCA**
RC (Min.)
Warranty (Months)
Dimensions (inches) L | W | H
Terminal

40R
MTP-40R
590
740
105
72
10-7/8 x 6-7/8 x 6-7/8
Auto-Top Post

47
MT-47
590
740
85
60
9-5/8 x 6-7/8 x 7
Auto-Top Post

Note - when the exide failed, the test at pep boys still showed it was good - meaning that I didn't argue about the warranty, I just bought a new one. $55 is still a fine price.

The battery cover on the positive terminal is white plastic (I have seen orange, though).

No information on the weight of the Exide/Interstate batteries.

The Interstate was a Megatron.

Batteries may last longer in warm climates without cold snaps. In other words, you are less likely to get stuck in warm weather. I had this car in TX and CA for the last 3 years of that Interstate battery.

Kevin

Robby

Thanks for all the info Kevin. Mine was used in Knoxville the whole time- not very cold here, but, definately less consistent (w/more cold) than CA & TX. I didn't hear about the MTP-40R- I assume that's an Interstate? It looks like it's pretty CLOSE in size to the MT47- an inch longer in length, but 1/4" shorter in height. I may just throw my scale in the car for the next few days & make a quick stop at Pep Boys or Auto Zone or something...

Thanks again,

89magic98

Right - it's an interstate.

The space is so tight, 1/4" makes a big difference. I'm sure that 40R is the right size. Way back when, I compared the Interstate Megatron to my original porsche battery. Each subsequent new battery was measured against the current one.

I went to Pep Boys, and they were selling some other sh*t brand I never heard of - Kragen had the Exide. I would shop around a few places before I decided on something.

Also, I can't imagine that (within a certain battery group # like 40R and battery technology) there would be a huge variation in weight of batteries.

Later cars (like the 968) have a big plastic cover between the base of the windshield and the rubber gasket at the back of the firewall, that covers everything. I have seen them for sale on ebay every now and again. I would not fabricate a big plate of aluminum to put over the top of the battery.

Robby

True- a tiny bit can make a dif w/the height, but, the MT47 definately doesn't rub- I have a piece of rubber (or something thereof) cut to fit the top of the battery that I have laying over the whole thing- I think it is actually squeezed in place b/t the top of battery & the hood itself, but am not positive- in any case, it's not too tight, although I wouldn't mind it being a hair shorter- I NEED to get some sort of underhood insulation- not sure about the aluminum reflective ones, as I've heard they can actually reflect engine heat back ON to the engine- wouldn't want that- the factory stuff dries up sort of eassily- not too sure what to do there- ideas? I'd like something to muffle engine noise slightly...

I would say you're right about the same battery sizes, etc, being roughly the same weight...

The cover you're talking about sounds pretty cool...

I've always wanted something to sheild the battery in case someone might want to fu** w/the cables- easy to cut from that position. Aluminum might not be the best choice though- carbon fibre???

89magic98

Robby,

Here's the exact cover I was talking about, on ebay:

http://cgi.ebay.com/ebaymotors/ws/eB...tem=2432502402

"This is a NEW OEM Porsche 968 Rear engine cover. This is also a popular upgrade for the Porsche 944. This cover goes along the rear wall of the engine compartment. "

The older I get, the more I like the OEM stuff (for all replacements). Think of how long it lasted the first time. It only has to last the life of the car.

-Kevin

IceShark

The numerical battery group numbers are the international battery manufacturers' standard group numbers to describe the length,width, height and terminal polarity. Everyone in the world makes to this convention.

I don't know if I would use a Group 47 because it stands 0.6" taller and you may risk shorting against the hood or poking dents in it if someone leaned on the hood, body flexed, etc. The 40R and 41 are the same except the 40R is 10.9" long and the 41 is 11.6", so the 41's usually are a bit more powerfull. Both will fit fine in our cars with no clearance issues.

Robby, if you are afraid of theft wire in a hidden fuel pump kill switch. It is going to have to dawn on the theives that that is what the problem is and then they are going to have to find it. Of course they could always tow the car but there isn't much to do about that outside of a Lojack would help find where it is, maybe.

I have a group 41 battery (due to cold location) that has 650 CCA @ 0*F. It weighs 36 pounds, a DieHard by Johnson Controls, the big battery maker in Wisconsin. Some Rennlister in SoCal was running a 15 pound dry cell and he didn't seem to have any problem starting. There is also one that is bigger and weighs in at 24 pounds. You may be able to get away with the 24 pounder in your climate and you would knock off 12 pounds.

Robby

Thanks Kevin! That looks great- it looks like it goes all the way across the car(?). That would be really cool... That starting bid is kind of pricey for what it is though- I looked through some of their other stuff (Partswerks) & they had several other things on auction that I really need, like an inner shifter boot- I noticed that several of the things I looked at were on their last day w/only several hours left & NO bids- maybe Partswerks could see this & take a hint- if everything they offered started about 50% lower, then they may actually get rid of some stuff :-)

If you find those for sale anywhere else that is a little more reasonable, please let me know... I wonder if either of the #'s John listed above were for this piece....John? Anyone else?

Thanks a lot,
Robby

Robby

I'm going to have to check mine again to make sure on the weight- I just aquired a more accurate bathroom scale, AND, it's been so long since I weighed mine, but, I'm almost positive it was b/t 30 & 31lbs. The ~5lb dif for the extra 60CCA wouldn't be worth it to me for THIS climate. But, I'm afraid I'm running pretty much bare minimum for my conditions, etc.

The PO's battery never shorted (that I'm aware of) but DID leave a slightly colorful mark The reason I got the piece of rubber I mentioned was b/c of this, to keep the terminal from touching the hood- it was VERY temporary, as it strained the hinges slightly to shut the hood- I could feel it- the extra tension it took to shut- the pad is about 1/2" thick, but, is fairly squishy, so I got by w/it, but wouldn't have done it for more than a week or so.

I would kill for a 24lb battery... I'm going to check out the site you mentioned the other night & see what they have...

Thanks again guys...

89magic98

I think that goes all the way across the car.

That's probably a fair price. They are hard to find because they are hard to describe / search for on ebay. I think I searched for "968 cover".

Partswerks could price their stuff lower, but keep in mind that this is a new item, not used. It might be hard to find a used one for a lower price. Also, sometimes folks who need parts in a hurry do not bid on items from Partsweks. My experience is that you will get the item ~10 days from end of auction, which meets some people's needs and not others.

The 477 number above is a VW number, it's unlikely that this is for a part that would have only appeared on the 968 series. You could send an e-mail to the partswerks guys and ask for the part number for your reference. Keep in mind that the Group 41 batteries (or similar import batteries) had the + cover because in some VW's the batteries were stored under the rear seat (or so I heard), and the seat springs could sag and short against the positive terminal.