JFP in PA

You are in the correct forum. Before putting an engine that has been used in class for years, I would be prone to pull it apart to make sure everything is there and no one has dropped a screw or nut into the internals. An engine that has been dormant that long may also have corrosion built up on the crank journals from sitting.

Welcome to RennTech PIWIS is the Porsche factory diagnostics system, and is only available as a lease for $20,000 for the first year.

The 1997 to 1999 Boxsters had two microswitches. One of those two microswitches was the black lever microswitch, which is mounted on top of a bracket that surrounds the electric motor. The bracket is also covered by a black plastic cover with a slot on top of it where the black lever pops up. The electric drive motor for the convertible top is located directly in front of the third brake light, on the rear wall of the convertible top well. This switch stops the electric motor when the top is down. The second switch is on the drivers side B pillar and is the one that turns the dash light off. It is a simple on/off switch that can be tested with a multimeter.

On a 99 Boxster, the top down limit switch is on the rear of the driver's side B pillar.

What year is the car? The red clip is also depressing the limit switch in the top catch, which also activates the sensors.

Welcome to RennTech From the sounds of it, the company in CA sent you a different unit which does not recognize your keys. You need to either get your original unit back from them, or you are about to spend a lot of money for keys, immobilizer, and programing at your local Porsche dealer. These units cannot simply be swapped, they have to be programmed to match the car and keys.

It is either that, or your top limit switch has failed. The red clip only came on cars with the factory hardtop.

Do you have the red clip installed where the convertible top latch normally goes:

Welcome to RennTech The DME MUST be the correct one for the car, and the car’s keys, immobilizer, and DME must all be coded to work together. That will require access to the PIWIS system to complete, after which you will need to address all of the car’s system control modules to get everything successfully talking to each other.

Doesn't happen because the car the family is in had a 700-800CCA or so battery with loads of current reserve. But with a lightweight battery with limited current reserves (read amperage), it would definitely be a possibility given enough time.

I would not bet on that, modern load testing equipment can load test the alternator in the car, and can even test the diodes' with it in there. Units can be pricey, often $4K (US) or more, but will test the entire system.

Sorry, but no, voltage and amperage out put of the alternators in question were dead on rated spec for the vehicle involved, and remained so under load; the weak spot was the amperage reserve, not the voltage reserve, in the battery during periods of high demand. 😉

No one here is "demeaning" your postings. Our intent is to help people with problems, and provide some educational context for all readers to consider when considering potential purchase decisions. My comment on headlights dimming was a real world experience that has occurred more than once when customers with light weight Li batteries brought cars into the shop complaining of these problems. Subsequent testing showed their charging systems were performing completely within normal specs, but when the AC clicked on, or a strong base section hit the stereo system, the lights dimmed because the available reserve amperage capacity of the battery was not up to the conditions. To demonstrate to the customer where the problem actually was, we put a brand new 800 CCA AGM battery in the car at no charge to the customer, with the agreement that they would return in a day or two to tell me what happened. In every case, they came back and said the problems had disappeared immediately and did not reoccur, and most purchased the battery we had installed for them. Those that did not purchase the replacement battery at least left the shop understanding why the problem happened, and in every case remained a good client with a better understanding of their cars. As for race cars, as another poster mentioned above, they have relatively very low power draw when out on the track, so a light weight battery with enough current output to run the few electronics use is sufficient. But when the car pulls into the pits and has to shut off for refueling or tires as required by the sanctioning body, the light weight Li battery was not up to spinning over the hot, high compression engine under restart, so they would plug in a high output conventional battery to get it going again. Under those conditions, reserve amperage capacity momentarily become critical, and demonstrates the limitations of lightweight batteries. At the end of the day, it is your car and your money. The battery you installed may serve you needs well in the climate you reside it, but for someone living in northern Montana, where the snow is already on the ground and daytime high temps are in the mid teens Fahrenheit, it might not be such a good idea. So context becomes important.

The Li battery business is suffering from a similar problem that the light bulb business had when switch from incandescent to LED. People had long associated bulb wattage with light level output, even thought wattage was actually measure of how much energy the bulb consumed and heat it generates rather than light output levels. So when consumers saw that an LED replacement for a 7 watt night light bulb only used 1.3 watts of power, their immediate assumption was that the LED would be much dimmer in light output than the incandescent bulb, which was anything but correct; and that stalled acceptance of the LED replacements for a period of time. Fortunately, there was another widely accepted scientific standard for light output: Lumens So when comparing replacement bulbs, consumers discovered that a 25 watt incandescent bulb and a 3 watt LED bulb both produced 130 lumen, meaning they were equally as bright, and that a 40 watt incandescent had the same lumens as a 5 watt LED, consumers now had a sound and reproduceable way of relating the product specs to their needs. Unfortunately, no such relatable second scientific measure currently exists for comparing conventional batteries to Li based units amperage performance under the same conditions. As as shown by the comments I quoted above, even within Li battery manufacturers there is no mutually agreed upon "equivalency" standards that either the BCI or SAE could buy into, much less help consumers make purchasing decisions.

He also went on to state that you could use their lightweight Li battery in a daily driver, "..as long as it is not used in cold weather.", without defining how cold that weather really was. Li technology for automotive use is a relatively new and evolving technology, and a very interesting one at that. But like most emerging tech, it still has a bit of the "wild west" in it that will shake out over time, but using "equivalencies" that seem purposely deceptive to sell the products is not helping their case any.

Here is an interesting published statement by a representative of the Antigravity Li battery company about their use of "equivalency ratings" used by Li battery manufacturers: "Unfortunately for you consumers....the waters are muddy because none of the lithium battery company put the ACTUAL and REAL Amp Hour of the Capacity ON the Battery itself.... For example most of the battery companies including Antigravity go by a "PB-EQ" (means-"lead-acid equivalent") rating which is essentially stating what size our Lithium Battery is roughly equivalent to the Starting ability of a Lead/Acid Battery. And even this PB-EQ rating is not accurate because a company like Deltran, who makes the Battery Tender lithium battery version will state they offer a battery that they claim is equivalent to a "20 amp hour lead acid battery" yet the size of the lithium battery pack inside their battery is actually only 7 REAL AMP HOURS. At the same time a company like us, Antigravity, will claim we offer a battery that is equivalent to "20 amp hour lead acid battery" yet our lithium cell pack will be 12 REAL AMP HOURS... " I particularly like the "roughly equivalent" statement.

If there is one thing all Li batteries do not like, it is being overly discharged (read deep cycled), which really damages them. This is why many newer Li batteries have a "BMS" or electronic battery management system included in their construction, which will step in and cut off the battery before it gets into an overly high discharge condition. Most Li battery BMS systems also include thermal protection as Li cells do not like getting very hot either.

Li technology is very interesting, but also quickly evolving. One way to look at light weight LI batteries to to watch what happens with race teams at the track; most serious race cars run Li lightweight batteries with one major caveat: they don't use them to start the car, only to supply energy reserve while the car is running. For starting in the pits they hook up a conventional AGM battery: There are Li batteries that are fine for daily drivers, with high CCA ratings, but they are also not super lightweight and expensive because they are relatively low production item. Even Porsche released an Li battery for street use, but it was over $1700 at retail.

But otherwise the underlying battery appears to be the same unit.

They both appear from their dimensions and other specs to be the same battery ("Starter Battery - 68Ah EqPb lead-acid/AGM/GEL equivalent", etc.), but with different terminals.

If it truly was, it would be purely luck. Interestingly the battery manufacturer's website says, and I quote, "up to 400CCA for ICE engines in HYBRID models with 900CA available at the press of the button" (notice we are jumping from CCA @ 0 F to CA ratings @ 68 F in that statement), apparently referring to its reserve cell capacity when a button is manually depressed, but at 68 F, not 0 F; and goes on to state, "Specifications: 68Ah PbEq, 400CCA with Push Button Reserve", so at 400 CCA (without the manual reserve button depressed) it has about 1/2 the cold cranking power of a conventional or AGM lead/acid battery of 800 CCA. As with most lightweight Li based batteries we have seen in the shop, it is low on amperage capacity. Every one we ever saw suffered from low capacity problems (headlights dimming when the stereo or AC was running, poor starting in cool/cold weather, etc.). There is no such thing as a free lunch. Have a nice holiday week end.

Actually, it is not. You simply cannot take values for a smaller battery and extrapolate them to a larger unit, or visa versa. There are many other factors (internal conductivity, heat retention, cell pack, conductor resistance differences, etc.) that complicates such a mathematical solution attempt to the point of being unreliable. This is why battery manufacturers continually test their batteries to see how they rate rather than attempt calculated performance projections. If it was simply a matter of extrapolation, life would be a lot simpler in the battery business, they could save a whole bunch of money by not testing or having large test facilities, plus the technical consortiums (BCI/SAE) who's standards they have agreed to adhere to require actual repeatable test data rather than extrapolations.

As someone that spent a significant part of his career in the battery business, your use of "assuming the proportions are the same" is more than seriously flawed. The CCA test used by the BCI (Battery Council International, the international technical consortium that sets standards for battery ratings and testing procedures used by battery manufacturers world wide) is very similar to the one used by the SAE (Society of Automotive Engineers); which requires storing the finished and fully charged battery a 0F (-17.8 C) for a period of 24 hours, then load testing it to determine its CCA rating. There is no known "proportioning" formula for determining this value, only hard testing data. Lightweight battery manufacturers have been "inventing" unique rating values and "equivalencies" without a basis in technical facts, and that are really totally meaningless, simply because they know what the outcome of publishing the more widely accepted testing data would be: Their batteries would appear weak compared to conventional SLI (starting, lighting, ignition) batteries.

I would also like to know the unit's cold cranking amperage (CCA run at 0F after 24 hours), not the cranking amperage (CA which is done a 68 F) in the specs. A lot of these small, lightweight units are fine for race cars, but fall flat on their faces (literally) trying to spin over an engine at 20 F.

We always did it on a lift with an engine support bar under it before we undid the mounts. You only need to drop it a couple of inches to make getting at it much easier, not out of the car. Usually, the nut on the ground is not in bad shape, and a quick spray with a good penetrating oil always helps. Just be sure to wipe it off before putting it back together again, and put a small dab of anti seize inside the nut.