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My 1991 Spider is dead. Last week I went out to take the car for a spin and it was totally dead; no dash lights, no nothing. Took the battery out and carried to the local auto parts store, bought a new battery. Today, a week later the car is totally dead again. What is wrong? Can anybody help me?
 

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Looks like you have a battery drain.

Do a search and you will find plenty of reading.

The most common issue we have is the footwell lights stay on.

Charge your battery, and see if the footwell lights are on.

The lights, one on each side, are also the switches. Rocker switches. One way, is always on (sorry don't remember which way, left or right), one way always off and centre, uses the relay.

If it is in the centre position and still won't turn off, then your issue is the switch in the door jamb.

Good luck,

Vin
 

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Check the condition of the ground cable there in the trunk, where the lug on the end of the cable grounds to the car body. Clean it with a wire brush, clean the lug itself, and clean the bolt threads also. Use battery cleaner on the female threads. If you're part Teutonic like me, you might go overboard and apply dielectric grease to the bolt, and lug, and a serrated lockwasher to ensure constant ground over time. All the batteries in the world won't help you unless you've got solid, clean grounds.
 

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Are you sure your alternator is charging the battery?
quick simple test is when running, voltage across batt terminals should be about 14.4 volts and around 12 when shut down. For a real diagnosis, an amperage output test should be performed. start the car, turn on lights A/C, heater fan etc. then using an inductive ammeter place it near the main output wire from the alt and see what the output is. Alternatively some parts stores can do a "load" test but beware technicians that have no idea what they are reading.
 

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When I was in the car sales business we always disconnected the negative terminal on the batteries on both new and pre owned cars that was in our stock.
My Spider is one of the (electrically) simpler ones. If I know I will not use it for a week or more, I disconnect the negative terminal and it'll start promptly when connected again. You can get negative terminals that disconnect with a twist of a winged handle on its top.
After its winter hibernation, 4-5 months, I use jump leads from another cars battery to start it up the first time. This way you never drain the battery completely. My battery is now 7 years old.
Erik
 

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Battery Chemistry

Summary: maybe nothing is broken, just incompatible.

The Bosch K1 alternator as fitted to our Alfas is rated at 14 volts and 65 amps. So under ideal conditions the alternator will supply 14 volts (you may actually see a little more, up to 14.4) at up to 65 amps. After that the voltage will start to drop off. 14 volts is the name plate specification so a slightly out of spec alternator will work better. You may have a difficult time returning one for only meeting spec and how many would you have to try before you find the 14.4v output alternator.

Again, ideally you should see 14 volts at the battery terminals when the engine is running, in actuality you will see less due to voltage drops at every connection and resistance between the alternator output terminal and the positive battery terminal. This also applies to the ground path from the alternator case to the negative battery terminal.

These resistances work against you in more ways than one. The voltage dropped at these resistances is not static, the more current drawn through all those connections and resistances will cause more volts to be dropped across each resistance in the battery charging circuit leaving less volts to reach/recharge the battery.

What did you buy for a battery? This Bosch K1 alternator will not fully charge a modern chemistry battery.

The common lead acid battery has 6 cells, each making 2.1 volts connected in series to make a 12.6 volt battery. Charging requirements should be around 2.3-2.35 volts/cell or 13.8-14.1 volts at battery terminals. A pure lead/acid battery is not applicable to automotive use as pure lead is too soft to withstand the rigors of bouncing down the road. To counter this battery manufacturers added antimony to the lead to strengthen it. Antimony added to the lead grids acts like a catalyst and makes out-gassing worse and water has to be added rather frequently. Remember the Delco Eye so you could more easily watch your battery fluid drop and know when to refill?

Battery manufacturers added calcium to both the positive and negative electrodes in the early 70s. This reduced out-gassing to low enough levels to allow the introduction of maintenance-free batteries. Lead/calcium batteries also required a higher charging voltage. GM changed the alternator outputs to 14.8 volts for cars equipped with their lead/calcium battery, the Delco Freedom II. My batery charger has a switch to select conventional or maintenance free, changes output voltage Replace your factory Delco Freedom II with a traditional lead/antimony battery and you would "boil" the water out of it in a short while.

There is a hybrid battery that adds antimony to the positive grid and calcium to the negative grid. Recommended charging voltage for a hybrid is 14.3 volts. 14.8 volts won't harm the hybrid battery but it will require periodic topping off the battery fluid.

Cars like ours (Bosch charging systems) with voltage regulators set at 14.0 volts will not fully charge lead/calcium or hybrid batteries. It is a common story cars with 14.0 v regulators leaving their owners stranded shortly after a new battery was installed. A week or two of sitting in the garage, with no load other than the electric clock and burglar alarm, can discharge a battery rather quickly if it was never fully charged.

On one or more other car forums regarding Bosch charging systems there are articles about adding a silicon diode into the regulator circuit to raise the voltage by the 0.7v forward bias voltage or adding an adjustable regulator to your alternator.

The newer Gel and Absorbed Gas Mat batteries do not require a high level of mechanical strength as the lead is held in place by the gel or glass matting. A lead/calcium alloy helps reduce out-gassing and self discharge held to 2% - 10% per month. This also bumps up the charging voltage requirements.
 

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86spider, thats a really comprehensive and informative reply (thanks for posting this) but its left me a bit confused. What battery would you recommend for our cars, if the modern ones generally available would not be charged properly?
 

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That's a pretty long writeup considering the original poster probably just left one of his kick lights turned on.

The "modern batteries" 86Spider is talking about are AGM cells (like the Optima) or the newer calcium cells. If you just use a normal lead acid batteries like they sell at the auto parts store you'll be fine with the stock regulator.
 

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Anglospider,
The battery for our cars i think would be a lead-antimony/acid battery. That is what our charging system was probably designed for back in the day. The problem being that I don't know if you can purchase one anymore. I've heard stories of Mercedes dealers (in the 80s and 90s) telling their custustomers to purchase the Mercedes Benz battery after complaining about the electrical system performance with their new X brand battery. That and Bosch was slow to catch up on the changing battery chemistry and essentially kept their head in the sand until the mid 90s. Mercedes, BMW, Volvo, and Porsche forums all have similar stories/complaints. I personally suffered through this for several years after the purchase of an expensive, advanced technology AGM battery which replaced an expensive name brand maintenance free battery. The AGM was replaced twice under warranty after the undercharged abuse killed it. The shop declared my charging system perfect several times. It seems they were unaware of the differing requirements of their own products.

I had to find a slope to park on at the airport so I could roll start the car after a week out of town. A solar charger helped but eventually I purchased an adjustable regulator from IAP and set it for 14.5 volts at the battery terminals. That brought an end to my starting issues and a few other electrical gremlins also. Surf the euro car sites and you will find many referrals to a Volvo site selling an adjustable regulator.

I just did some research on the websites of Interstate, Douglas, and Deka. I found no marketing hype on specifically adding antimony or calcium or anything to their grids but on several MSDSs (material safety data sheet) I did find several lead or lead oxide compounds along with antimony and calcium, separate and together, along with arsenic and tin. I don't know which model battery each sheet corresponds to so kind of worthless and just because it isn't listed doesn't mean it isn't there.

It seems on the face that Interstae may have a product or two that would be lead/antimony.

I will try to make some calls next week and see what they will divulge.

If something doesn't make sense I will fix it when the the doc cuts back on the pain med. it took me several hours to squeeze out these posts, I keep falling asleep.
 

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Gubi, I totally agree - it sounded to me like a light had been left on, particularly as the same thing happened with the new battery.

I am interested in 86spiders explanation because my wife's 12 year old Peugeot never seems to charge its battery to the extent that a battery charger does, even after a long run.
I have just bought a new battery for it but went for a calcium one thinking it would be better. Sounds like it could be no better, maybe worse, if the car isn't charging it fully. I will check charge voltage in the car.

But JDB101; check what lights are left on: footwells, glove box, etc
 

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Alternate regulators for Bosch alternators

A little surfing turned up these, all for 28 mm Bosch alternators:

Dave Barton Volvo, alt source for adj reg.

Volvo Adjustable Voltage Regulators

Fixed point regulator, 14.4 volt set point
# IB373A - Voltage Regulator, Brush Holder Assembly for Bosch Alternators - 12 Volt, A-Circuit, 14.4 Volt set point


14.5 v fixed point (Alfa, 72-98)
# IB353 (359104) - Voltage Regulator, Brush Holder Assembly for Bosch Alternators - 12 Volt, A-Circuit, 14.5 Volt set point

14.8 v fixed point Citroen and Peugeot
# IB356 - Voltage Regulator, Brush Holder Assembly for Bosch Alternators - 12 Volt, A-Circuit, 14.8 Volt set point, 120 ohm Resistor

There are others and external versions

Found similar units on eBay
 
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