What is a good way to maintain my RX-7 battery? I keep the car as a backup vehicle and only drive it occasionally, but I think I need to do a better job with the battery (and probably other items). The battery drains after a week of sitting.

A "maintenance charger" might be a good investment (such as the Battery Tender Plus). I've also seen solar chargers that sound interesting.

Since my car sometimes leaves me stranded when I am away from home, I also thought that a portable "battery jumpstarter" might be a good option (and I already carry jumper cables). Maybe someday I will replace the battery cables or do some troubleshooting.

Another thing to do is just to disconnect the battery cables when I don't drive, but I read that the battery might be better preserved by a low-voltage trickle charge.

What's the best option (most convenient and least costly)?

 

If this is the '84 and you don't have an alarm system wired directly to the battery, then just unplug the alternator and then charge the battery every month or so.

If it does have the alarm system, that's still too quick for a battery to be discharged completely, in one week, that is. You've got a problem somewhere. If you did the alternator upgrade, then just unplug it when not in use or charge the battery each Saturday.

I was going to do a write-up as a follow-up to an old tech article I did on that upgrade that would allow the idiot lights to still work, which is something the "popular" solution doesn't take into account. Takes a bit more time but it's worth it and it cures the drain completely. If it wasn't for the alarm system, it could sit for half a year and then start right up with no charging at all.

Mario III

 

I just got my car out of storage.I left the Trickle Charger ON for 4 months!..it started in 5 Seconds.
I believe in Trickle chargers.They have an auto shut off anyways,and only allow it to put out minimal amperage.so it doesn't Bombard the battery with alot of juice.
If you are in a Severe Weather area(hi temp.Cold Temp location) then a car battery will be subjected to alot of abuse and die quicker than a more temperate climate location(where the weather is not changing between hot and below freezing temp).
Normal battery life expectancy is about 5 year max,so if the battery is older than that it has served you well and should be replaced.

 

ive had good luck from the battery maintainers for motorcycles etc.that are 12 volt 1.5 amp. I just instal it in the car by the battery and run the electrical plug down to the bottom of the front fender and run it through the plastic trim thee so i can plug an extension cord up quickly without even raising the hood at times when I know i wont be driving the car for a while. its fully automatic.

 

just disconnect the pos cable from the bat when car isn't being used.

 

+1...just get a good "trickle" charger and call it a day. Probably like 30 bucks...maintains the battery and increases the life.