spyderphile

Hey guys. If I don't drive the car for 5-6 days, the battery drains completely; doesn't crank. It has happened three times. First time, they found that the front trunk's latch was getting actuated, apparently; so, they changed the latch (don't remember the details). Since then, it has drained twice. No fault code, nothing. Parasitic discharge is below the normal rate. No frequent short runs. It is kept in locked state (so that everything shuts down). Battery test indicates good. Alternator is apparently good. I was told that if the battery or alternator acts up, there would be codes. The battery is original/initial one. Last winter, I was able to start the car after six weeks or so to move to a different parking spot to plug in the charger (that issue has been mitigated; have a spot with wall socket). So, the problem is recent.

Could the battery be on it's way out, though the tests indicate otherwise? The battery apparently is a low-capacity one. Should I just change the battery? Has anyone tried a higher-capacity (non-OEM) version?
Thanks.

cneigho

Hey Henry, I was in a similar situation. Interstingly I have found that leaving the car unlocked while in the garage actually drains less juice rather than locking it and activating the security system. My OEM battery drained a few times after prolonged time of sitting locked in the garage during the cold months. I recharged it and everything worked fine but soon found the ability for it to maintain its charge was reduced by sitting so long. I elected to change eventually to ensure CCA but to also save weight. Since then, I have a smaller odyssey pc680 battery in my 987 Spyder that I use in the summers. The battery has been great, saves around 35 lbs. and I just make sure to put in on a trickle charger if I don't drive it for a while. For slightly more capacity than the 680, I use the Interstate MT Megatron 47 in the winter and still saves a little weight. Both seem reasonably priced.

ChicagoSpeed996

spyderphile

Thanks, cneigho. That's an interesting observation. I was told by Service that if the car is locked, the system shuts down stuff after some time and goes into Sleep Mode. I will look into batteries you mentioned. Let me check with the Service again about discharge between locked and unlocked states.

Thanks, ChicagoSpeed996. I don't have PCM. At the Service, they did check the parasite discharge; found it to be below normal.

Interestingly, during the third visit, there were two other 981 Spyders with battery issues! However, their problems appeared to be not being able to be trickle-charged. Apparently, some gateway setting was turned off by default, causing trickle-charging issue.

I had a similar problem with the S2000 during spring. After changing the battery, it can be left untouched for a few weeks. So, I might just change it!

Viper pilot

Yes, definitely get a new battery if your's is over 4 years old. Plus, letting the battery discharge completely will only make it continue to fail faster next time. Change the battery!

Jamie140

The battery on mine was really weak. I replaced it this spring and haven't had an issue since.

When replacing the battery, be aware the cables originate in the firewall and are quite short. Get a battery with the posts on the rear portion or one that you can turn 180 degrees so the cables reach.

Farland

Hi, New member here. Recharge battery to 100% while using a lead-acid charger with desulfation mode selected. Next, have someone perform a load test on the battery. If test shows the battery can provide the cranking amps as advertised with battery voltage remaining above 9, battery is good enough to keep. Otherwise, you may want to use a charger more often with your next lead-acid or look into getting a lithium iron phosphate battery where such a level of maintenance is usually not necessary.

spyderphile

Viper pilot:
Thanks. The battery is less than 3 years old. Car was built by end of '15. Agree that the battery can deteriorate at a faster rate with multiple/frequent complete discharge.

Jamie:
Thanks. Kinda validates my rational that some batteries could go sooner than others, knowing you had to replace yours as well. Good to know about limitations with the cables.

Farland:
Welcome to the forum! Thanks for the pointers. The battery has passed relevant tests. Nothing stuck out as out of the ordinary. Nada!

Thanks everyone for suggestions; appreciate it. I had let the car sit idle for six days, intentionally, in locked state. Yesterday, friday, it didn't crank. So, jumped it and went straight back to the dealer, for the fourth time! Sure enough, the battery tested positive; no fault! By now, I had already preped the Service Advisor that we were replacing the battery, regardless what they find. So, we replaced it. I don't think I'm closing the book on this issue. I'm gonna repeat the six-days-of-idle test in a couple of months. If there is a non-battery issue, I need to find it!

Dalema

spyderphile

Yeah, looks like Spyder's battery is a low-capacity one to begin with. And, some of them seem to be losing their useful-life sooner. Are you talking about trickle-charge issue? Apparently, some gateway setting is turned off by default which causes trickle charging to fail. I use a wall socket and connect to the battery directly.

Dalema

Dazugus

Dalema, which dealer do you go to, and who is your SA?

Archimedes

I've been surprised by the exact opposite. My car can sit for a long, long time and still fire right up. I keep thinking I'm gonna have a problem when I forget to charge it, but I never do. And when I do put the charger on it after sitting for 4-6 weeks, it tops off really quickly. Perhaps there were some bad batteries that got out.

spyderphile

Yeah, I do think I got a bad battery. Well, I think, since the resolution isn't definitive. If the source of the drain isn't the battery, then we are back to square one! The Service has exhausted all possibilities. One scenario is that a component's draw spikes up randomly, but doesn't register in the logs. I will do my idle test (not driving for a week) in a couple of months and report back.

digitalrurouni

I usually double click the lock button on the keyfob when I park my car in the garage. I am told that saves juice by not running the 'weight sensor' or something in the car that detects if someone got in to the cabin. That saves some juice. But I second swapping out the battery for a new one.

Slightly off topic but the Antigravity battery is quite epic that I have in my car. it seems like the car starts up quicker and also the lame sounding horn that sounds when you lock the car is a LOT louder than before lol. Just seems like the battery supplies a very strong amount of current or something.