Serial battery killer
Discussion
I have a habit of killing lead acid batteries through lack of use. They either sit in the vehicles and get drained over time, or they sit in my garage and mysteriously die.
I have a classic car that I bought a year ago, it sits outside as I don't have indoor space. I need to move it off the drive from time to time to access my garage. Due to this, the battery needs to be jump started every time.
Yesterday I took the battery out to charge. It was at around 10v. I have a 10a 7 stage charger, I plugged it in and it was doing ok at around 12.5v. The voltage would start dropping off if I disconnected it, so I thought I'd leave it overnight. Whilst there, I had 3 other batteries in the garage. 2 were at 4-5v, and one was at 10-11v. I connected the latter to the already charging battery with jumper cables in order to kill 2 birds with one stone.
This morning I came to find both of them were hot and fizzing and at around 10v. This seems to be a revolving theme in my life. Am I cursed?
I have a classic car that I bought a year ago, it sits outside as I don't have indoor space. I need to move it off the drive from time to time to access my garage. Due to this, the battery needs to be jump started every time.
Yesterday I took the battery out to charge. It was at around 10v. I have a 10a 7 stage charger, I plugged it in and it was doing ok at around 12.5v. The voltage would start dropping off if I disconnected it, so I thought I'd leave it overnight. Whilst there, I had 3 other batteries in the garage. 2 were at 4-5v, and one was at 10-11v. I connected the latter to the already charging battery with jumper cables in order to kill 2 birds with one stone.
This morning I came to find both of them were hot and fizzing and at around 10v. This seems to be a revolving theme in my life. Am I cursed?
Car batteries dont like to drop under 12.0v.
In theory you should not let them drop under 12.2v as thats when you start to lose capacity and can do damage.
My advice is to charge to 12.8v and then re charge when it hits 12.4 to 12.5v. Batteries (in good health) in storage should only drop about 0.1v per month.
So you should only need to charge every 3-4 months. Good quality batteries might even eek 6 months before dropping under 12.5.
OP I suspect your issue is two fold. Firstly you are storing the batteries not fully charged to start with, secondly the battery in the parked car might have some parasitic drain. If it does not have a modern ECU (i.e if its pre 1990) then I would fit a kill switch. Or fit a trickle charger.
IME.
In theory you should not let them drop under 12.2v as thats when you start to lose capacity and can do damage.
My advice is to charge to 12.8v and then re charge when it hits 12.4 to 12.5v. Batteries (in good health) in storage should only drop about 0.1v per month.
So you should only need to charge every 3-4 months. Good quality batteries might even eek 6 months before dropping under 12.5.
OP I suspect your issue is two fold. Firstly you are storing the batteries not fully charged to start with, secondly the battery in the parked car might have some parasitic drain. If it does not have a modern ECU (i.e if its pre 1990) then I would fit a kill switch. Or fit a trickle charger.
IME.
NDNDNDND said:
This - just disconnect it.Batteries of differing quality seem to be more and less resilient too.
Mrs D had a Lion ECP cheapy that lasted a year before I had to run a battery repair cycle on it. Then a year after that it died whilst she was parked up eating her lunch with the stereo going, after a 1 mile drive on a cold day. So, I replaced it with a Yuasa and despite the same usage pattern it's faired much better and without regular top-up charges.
Mrs D had a Lion ECP cheapy that lasted a year before I had to run a battery repair cycle on it. Then a year after that it died whilst she was parked up eating her lunch with the stereo going, after a 1 mile drive on a cold day. So, I replaced it with a Yuasa and despite the same usage pattern it's faired much better and without regular top-up charges.
fasimew said:
I have a habit of killing lead acid batteries through lack of use.
That's it, right there.Lead acid batteries have very particular characteristics. They like to be fully charged all the time. They are NOT suitable for any form of cycling, as in discharge/recharge/discharge/recharge.
A car battery really wants to be "driven" at least once a week. If you can't achieve that then the best way forward is a battery tender.
As someone has already mentioned, as soon as a battery drops below 12v (after being charged and left to stand) it's heading for the exit. A good battery, fully charged and then left to stand for a while, should show 12.6 or 12.7 volts on a decent voltmeter.
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