Westco dead again.

Battery a month or two old. Car sat for 3 weeks while we were on vacation.
Won't crank. Thoughts? Just a bad battery?

On 2/17/2010 2:13 PM, Frank Berger wrote:
> Battery a month or two old. Car sat for 3 weeks while we were on vacation.
> Won't crank. Thoughts? Just a bad battery?
>
>
If the same vehicle continually has dead-battery problems with replacement
batteries I'd start to suspect the vehicle rather than the battery. High
phantom current draw? Defective charging circuit? Cables? Starter with
higher-than-expected current draw? I had the latter problem with a VW
diesel which caused a long troubleshooting sequence as the battery looked
good then bad then good.

In article > ,
"Frank Berger" > wrote:

> Battery a month or two old. Car sat for 3 weeks while we were on vacation.
> Won't crank. Thoughts? Just a bad battery?

AGM batteries don't like to sit for weeks without being disconnected,
don't like to be charged when low from a Miata's alternator, and don't
like cold weather. They're OK if you drive everyday or keep them on a
battery tender (trickle charger) between drives and never let them get
low.

My advice is NOT to bump start the car or get a jump from another
battery, because then the Miata's charging system will cook the Westco
and ruin it. Instead, try charging it at 1 or 2 amps for a couple of
days, and see if that revives it. If not, as Dr. McCoy always said,
"He's dead, Jim."

I gave up on Westcos after killing two of them through personal
ignorance. I bought a wet-cell Super Start from O'Reilly, and even in
cold weather it spins the starter faster than any AGM. It's taller than
OEM, so I also needed a new tiedown rod. It vents through the OEM
tubing, with some larger tubing as adapters. Many of us who don't drive
our Miatas every week, or have no patience with the extra care required
for AGMs, will be better served by wet batteries.

--
Lanny Chambers
St. Louis, MO
'94C

John McGaw wrote:
> On 2/17/2010 2:13 PM, Frank Berger wrote:
>> Battery a month or two old. Car sat for 3 weeks while we were on
>> vacation. Won't crank. Thoughts? Just a bad battery?
>>
>>
> If the same vehicle continually has dead-battery problems with
> replacement batteries I'd start to suspect the vehicle rather than
> the battery. High phantom current draw? Defective charging circuit?
> Cables? Starter with higher-than-expected current draw? I had the
> latter problem with a VW diesel which caused a long troubleshooting
> sequence as the battery looked good then bad then good.

This is the first time a Westco died in less than 3 years.

On 2/17/2010 2:13 PM, Frank Berger wrote:
> Battery a month or two old. Car sat for 3 weeks while we were on vacation.
> Won't crank. Thoughts? Just a bad battery?
>
>
I had sort of the same problem! 2 year old glass mat battery. It died
due to an after market under hood courtesy light switch stuck on for
several days. The battery was completely flat. Overnight charging got
just enough into the battery to get a slow crank with (fortunately) a
start. The battery had higher than normal internal resistance, and after
additional charging still dropped lower in voltage than it should under
a starting load. Replaced with another glass mat battery. I'm fortunate
in that we have a local multi-generation family owned battery, starter,
and alternator shop that carries batteries for Miatas.

Chuck wrote:
> On 2/17/2010 2:13 PM, Frank Berger wrote:
>> Battery a month or two old. Car sat for 3 weeks while we were on
>> vacation. Won't crank. Thoughts? Just a bad battery?
>>
>>
> I had sort of the same problem! 2 year old glass mat battery. It died
> due to an after market under hood courtesy light switch stuck on for
> several days. The battery was completely flat. Overnight charging got
> just enough into the battery to get a slow crank with (fortunately) a
> start. The battery had higher than normal internal resistance, and
> after additional charging still dropped lower in voltage than it
> should under a starting load. Replaced with another glass mat
> battery. I'm fortunate in that we have a local multi-generation
> family owned battery, starter, and alternator shop that carries
> batteries for Miatas.

I don't think there was any drain on the battery. There's an MK Battery
about 12 miles from where I live where I get the Westco. I'll return the
battery and get a replacement for full credit, I'm sure. Hopefully this
afternoon.

There usually is some drain, called "dark current". Such things as the radio
memory & clock, car alarm, ECU memory (trim settings) keep alive, etc.
Usually an aftermarket car alarm is the culprit.

"Frank Berger" > wrote in message
...
> Chuck wrote:
>> On 2/17/2010 2:13 PM, Frank Berger wrote:
>>> Battery a month or two old. Car sat for 3 weeks while we were on
>>> vacation. Won't crank. Thoughts? Just a bad battery?
>>>
>>>
>> I had sort of the same problem! 2 year old glass mat battery. It died
>> due to an after market under hood courtesy light switch stuck on for
>> several days. The battery was completely flat. Overnight charging got
>> just enough into the battery to get a slow crank with (fortunately) a
>> start. The battery had higher than normal internal resistance, and
>> after additional charging still dropped lower in voltage than it
>> should under a starting load. Replaced with another glass mat
>> battery. I'm fortunate in that we have a local multi-generation
>> family owned battery, starter, and alternator shop that carries
>> batteries for Miatas.
>
> I don't think there was any drain on the battery. There's an MK Battery
> about 12 miles from where I live where I get the Westco. I'll return the
> battery and get a replacement for full credit, I'm sure. Hopefully this
> afternoon.
>

In article >, "Chuck" >
wrote:

> There usually is some drain, called "dark current". Such things as the radio
> memory & clock, car alarm, ECU memory (trim settings) keep alive, etc.
> Usually an aftermarket car alarm is the culprit.

Dark current on a stock NA Miata is no more than 20 mA, just the radio
presets, clock, and stored ECU error codes. Aftermarket alarms, of
course, can add any amount from very little to a dead short.

--
Lanny Chambers
St. Louis, MO
'94C

Assuming 20ma dark current, that would amount to about 10AH over three
weeks. An older battery might not have that much spare capacity.
Actually, I'd bet that the newer years have a bit higher dark current, and
aftemarket accessories might be involved as well.
"Lanny Chambers" > wrote in message
...
> In article >, "Chuck" >
> wrote:
>
>> There usually is some drain, called "dark current". Such things as the
>> radio
>> memory & clock, car alarm, ECU memory (trim settings) keep alive, etc.
>> Usually an aftermarket car alarm is the culprit.
>
> Dark current on a stock NA Miata is no more than 20 mA, just the radio
> presets, clock, and stored ECU error codes. Aftermarket alarms, of
> course, can add any amount from very little to a dead short.
>
> --
> Lanny Chambers
> St. Louis, MO
> '94C

Top posting becayse you did.

Don't have none of that stuff.

Chuck wrote:
> There usually is some drain, called "dark current". Such things as
> the radio memory & clock, car alarm, ECU memory (trim settings) keep
> alive, etc. Usually an aftermarket car alarm is the culprit.
>
> "Frank Berger" > wrote in message
> ...
>> Chuck wrote:
>>> On 2/17/2010 2:13 PM, Frank Berger wrote:
>>>> Battery a month or two old. Car sat for 3 weeks while we were on
>>>> vacation. Won't crank. Thoughts? Just a bad battery?
>>>>
>>>>
>>> I had sort of the same problem! 2 year old glass mat battery. It
>>> died due to an after market under hood courtesy light switch stuck
>>> on for several days. The battery was completely flat. Overnight
>>> charging got just enough into the battery to get a slow crank with
>>> (fortunately) a start. The battery had higher than normal internal
>>> resistance, and after additional charging still dropped lower in
>>> voltage than it should under a starting load. Replaced with another
>>> glass mat battery. I'm fortunate in that we have a local
>>> multi-generation family owned battery, starter, and alternator shop
>>> that carries batteries for Miatas.
>>
>> I don't think there was any drain on the battery. There's an MK
>> Battery about 12 miles from where I live where I get the Westco. I'll
>> return the battery and get a replacement for full credit, I'm
>> sure. Hopefully this afternoon.