T
Terry Schwartz
Guest
This actually pretty easy. If you feel you really need to know, measure the quiescent current in the vehicle several minutes after the ignition has been shut off. It should be in the milliamp range. Now you can figure out the rate of discharge for the battery based on the AH rating. (NOT CCA). In hot or cold climates, derate the battery 20% for every year of life. (20% of the previous capacity, not the original capacity). BUT.... it really doesn't matter.
Vehicles with early electronics didn't manage the quiescent loads as well as modern vehicles. And added accessories can obviously add to that if they tap unswitched power.
You want to keep that battery charged to 80% or better of capacity. Because charging systems vary in algorithm and efficiency, and vehicles vary in dynamic loading, it's impossible to say "run the vehicle for X minutes every two weeks. But it is possible to pick a battery tender. Anything of decent quality today will taper the charge and many apply desulfating algorithms to the battery once it's charged. You can fearlessly leave a Schumacher or Battery Minder or Battery Tender on your dormant vehicle battery indefinitely.
The amp rating only makes a difference in the time it takes to charge the battery from a discharged state. Any tender can keep it topped off. I personally use tenders rated from 800ma to 4A and they all work fine on my many pieces of power sports equipment, as well as my winter-stored street vehicles, boats, and yard equipment.
Unless the battery is bad -- unusually high self discharge due to sulfation -- any tender has the capability to keep it topped off.
Note that final voltages are different for various types of batteries -- so if you are using an AGM or GEL battery, get the appropriate tender.
I *do* have some experience in this from both a personal and professional standpoint.
Vehicles with early electronics didn't manage the quiescent loads as well as modern vehicles. And added accessories can obviously add to that if they tap unswitched power.
You want to keep that battery charged to 80% or better of capacity. Because charging systems vary in algorithm and efficiency, and vehicles vary in dynamic loading, it's impossible to say "run the vehicle for X minutes every two weeks. But it is possible to pick a battery tender. Anything of decent quality today will taper the charge and many apply desulfating algorithms to the battery once it's charged. You can fearlessly leave a Schumacher or Battery Minder or Battery Tender on your dormant vehicle battery indefinitely.
The amp rating only makes a difference in the time it takes to charge the battery from a discharged state. Any tender can keep it topped off. I personally use tenders rated from 800ma to 4A and they all work fine on my many pieces of power sports equipment, as well as my winter-stored street vehicles, boats, and yard equipment.
Unless the battery is bad -- unusually high self discharge due to sulfation -- any tender has the capability to keep it topped off.
Note that final voltages are different for various types of batteries -- so if you are using an AGM or GEL battery, get the appropriate tender.
I *do* have some experience in this from both a personal and professional standpoint.