New battery issue

I just got back from the Mazda dealer where they replaced the battery in the '97 Miata. That's the third battery in three years. The car belongs to my son who's stationed in Hawaii and could only take one vehicle with him. I drive it once a week, usually about 16 miles. It does okay in the summer, but in the fall and winter (even here in Southeastern Virginia) it seems like it won't hold a charge and I have to jump start it quite frequently..

Today at the dealer's I was presented with a new idea. They suggested that with a gel cell battery, if you don't put an electrical load on the battery, the alternator just won't charge it. In other words, I could drive it a lot more and still not adequately charge the battery. So I'm supposed to drive the car with the headlights on!

Has anyone heard about this? Comments???

Jerry

Reply to
Jerry
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Jerry, I used to store my 90 Miata all winter and the battery would be just fine in the spring. All I ever did was disconnect the battery. There are a number of quick disconnect devices on the market that are easy to install. Frank Sawin

Reply to
Frank Sawin

They are supposed to last at least 10 years. Does this dealer know they have to be trickle charged, not put an a multi-amp charger?

Put it on a trickle charger. I have my spare on a Battery Tender from Pep Boys.

If you have an alarm system or so, the dark current might be too high. It may be a good idea to measure it, though I would think any good dealer should already have done so, in view of all the batteries they replaced.

I would not be comfortable with jump starting it that much, since the battery tends to convert a lot of the amperage into heat. See

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Maybe a grain of truth in it. From the link above:

] Now you'll almost for sure start, and then put your 2-amp charger on ] when you get home. This slow charge is important to do. The Miata ] alternator system alone will often not bring the battery back to full ] charge. This is not because the Miata's charging system is weak, just ] the opposite-it's strong enough to cause the heating of the battery ] without allowing charge stored in it.

Putting more load on the alternator would reduce its effective output a bit, I guess. Though I doubt it would be much.

I assume they checked that the alternator is indeed charging?

Leon

Reply to
Leon van Dommelen

Interestingly, my Westco took the cold today as a reason to desert me. (I got the Westco one or two years ago because I thought my battery was bad; that turned out to be the Priority Start device I had on it.) So I took my 8 year old original from the Battery Tender, swapped batteries, and was on my way in half an hour. They last and last.

The Westco is now on the Battery Tender for next time there is a problem.

Don't really know why the Westco gave out after a couple of start attempts. I took a fairly long drive to AutoX on Sunday. Maybe it was frozen? It was as cold as 23F last night.

Leon

Reply to
Leon van Dommelen

I had to replace The OEM battery soon after I bought the 99. It was marginal in the POE test, and after a couple of weeks would bairly turn the engine over. I was able to turn in the bill for a new Westco to the dealer, and get reimbursed. The Westco just failed with an odd symptom-- The engine would turn over, but the battery voltage was dropping just enough under a start load to confuse the computer. This caused an odd set of symptoms with the ignition system. (Ignition has four plug over coil packs, no plug wires, and depends upon the stock computer and sensors for timing. The Westco did fail a load test at the local battery specialty shop. (Current ok, but low voltage.) Usually, the normal run of the mill car battery falls flat on both when it's bad. In defense of the Westco (I hate to admit) the battery was abused-- run flat several times, etc. Naturally, the Westco failed just out of warrenty. The replacement glass mat battery is not a Westco, and ended up costing about $20 more.

Reply to
chuckk

FWIW: If the shop isn't expert in AGM batteries, the normal tests for lead-acid batteries won't mean much.

Reply to
Lanny Chambers

Reply to
miata newbie

Reply to
miata newbie

True, however the battery is rated at a starting current. By convention, the voltage should not drop below a usable voltage when a load equivilent to starting current is applied. I had been nursing the battery along by leaving it on a 1 amp charger overnight. If I was in say Chicago instead of mid Georgia, the battery would likely have faiuled completely at the first cold snap. At rated starting voltage, the current draw was only about 1/4 of normal for a good battery.

Reply to
chuckk

That was today. Not a murmur out of the OEM. I do not understand why, though. I measured the dark current and it was only 5 mA. In other words, the 4.5 days that it had been standing is no more than say keeping your lights on for 5 minutes after shutting down the car.

I wonder at what temperature the electrolyte freezes. Both times it was below freezing when the battery would not start the car. The car is outside, so it could get quite cold.

I am getting quite fast at swapping batteries. But then I spend the time again cutting off the lip from the negative battery lead to reduce wear on the screw-down nut. ;)

Leon, and Bozo, back on Westco.

Reply to
Leon van Dommelen

There is always a load when the car is running. If nothing else, the engine computer and ignition system, not to mention various gages and such. Dealers don't always tell it like it is.

Reply to
chuckk

I have a '97 I bought 2 years ago with a Westco Battery in the trunk. I have a three mile commute and I live in the frozen (while wet anyway, British Columbia) north where we have short days and commute with the headlights on in winter, no trouble with the battery, and I drive with the daytime running lights on all the time. Last winter I parked the car for 4 months without disconnecting the battery, still no trouble. If I had your problems I would be looking for "dark current" problems, or charging system problems.

Reply to
bgt

"Jerry" schreef in bericht news:EsFkI7LVLls8-pn2-B65xcdhYOJTg@localhost...

i bought 4 years ago a miata '92 and every year i had to replace the battery. Even a stronger one does not give the solution. After 10 days the battery was empty. Several people had checked the electrical system, nobody had found any problem. Everything was ok they said. At the end i replaced the radio and from that day not any problem anymore. I think that the buffer-battery in the radio after the stop of the car was complete loaded (kind of a condensator/battery) and that after short time he was continious busy to reload this mini-battery. After i have changed the radio, the car has had a stop of 3 months because i was abroad and no problem then to restart my miata again.

sorry for the the mistakes in the language, i am a dutchman.

regards Douwe

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Reply to
douwe

Thanks for that idea. The CD player has been acting up anyway. I'll pass this on to my son so he can make a decision.

I had no problems reading it. I'm just thankful that I didn't have to learn (American) English as a second language.

Jerry

Reply to
Jerry

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