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What is draining the battery? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

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YOUR RESEARCHWhat is draining the battery? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Leading reported evidence

Disconnect but allow a minimal voltage

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Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

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Suggestion · Original poster

I have seen those battery disconnectors that disconnect but allow a minimal voltage to keep the radio and CPU memory active.

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What is draining the battery? - 986 Forum - The Community for Porsche Boxster & Cayman Owners
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Leading evidence: 'Disconnect but allow a minimal voltage' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Disconnect but allow a minimal voltage' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.

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Compare 2 other evidence results

Test circuit by circuit

Suggestion or failed attempt

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Unsuccessful attempts
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Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that contain suggestions
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0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

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Suggestion

Then follow JFP's advice on testing circuit by circuit for the abnormal drain.

Original post Read captured discussion
What is draining the battery? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Use battery maintainer now

Suggestion or failed attempt

No successful repair reported for this finding.

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Reported fixes
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Unsuccessful attempts
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Discussions
Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

I've started using a battery maintainer now that the weather has turned.

Original post Read captured discussion
What is draining the battery? - 986 Forum - The Community for Porsche Boxster & Cayman Owners
Frequently discussed actions (3)

These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.

Disconnect but allow a minimal voltage

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion · Original poster

I have seen those battery disconnectors that disconnect but allow a minimal voltage to keep the radio and CPU memory active.

Original post Read captured discussion
What is draining the battery? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Test circuit by circuit

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

Then follow JFP's advice on testing circuit by circuit for the abnormal drain.

Original post Read captured discussion
What is draining the battery? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Use battery maintainer now

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

I've started using a battery maintainer now that the weather has turned.

Original post Read captured discussion
What is draining the battery? - 986 Forum - The Community for Porsche Boxster & Cayman Owners
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Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.

5 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.

  • 986Forum: 1 discussions

0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.

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Generation: 20261026T161109Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

I know that it is an accepted thing that when you let the boxster sit for a few days the battery dies, however I am a little tired of getting new batteries. I went to the car this am and all I heard was click click, If it sits for more than 2 days, worse if cold outside, the battery barely starts the car. What is it that is draining the battery? The CPU? Alarm? I have seen those battery disconnectors that disconnect but allow a minimal voltage to keep the radio and CPU memory active. Would that work?

POST 2Original post

The list of what can be drawing power is almost endless; the alarm system, the stereo, GPS, radar detectors, etc. etc. Most don’t understand that something like a cell phone charger, even without the phone attached, still draws current. Best way to sort this out is to disconnect your + battery terminal (be sure you have your radio code handy) and put a digital volt meter (set to measure current) between the cable and the battery. Then pull one fuse at a time from the fuse panel and watch the current draw change. This will tell you what circuits have the drain on them, and identify the level of drain for each. The basic car electronics (alarm, immobilizer, computer, radio and clock) should show a total draw in the milliamp range or so; draws beyond that are where your problem lies………………

POST 3Original post

I would add that I have a 2001 S, and have let it sit for 2 weeks and it started right up. So what you are experiencing is probably not normal. I've started using a battery maintainer now that the weather has turned.

POST 4Original post

I hated dealing with parasitic drains- I would also look into a "battery brain".

POST 5Original post

and my no-modifications or additions Boxster sits for 3 weeks and starts right up in normal temperatures. Ask yourself what wasn't on the car when the factory delivered it and first suspect that. Then follow JFP's advice on testing circuit by circuit for the abnormal drain. The Boxster is smart enough to turn lots of things off as time goes by to save battery drain...if it is stock and everything is working right.

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