Personal computing discussed
Moderators: askfranklin, renee, emkubed, Captain Ned
meerkt wrote:Other than speed, is there an actual difference between "maintaining" and "charging" a car battery?
Some chargers have specs/blurbs that say they're good for charging batteries with capacities up to [X] Ah, and maintaining up to a larger [Y] Ah.
I don't mind waiting more. Any reason not to use a ~1A charger instead of 3-4A?
It's often recommended not to charge at a rate more than 10-20% relative to the capacity, but one article also recommended a minimum rate of 3% the capacity (for example, 1.5A for a 50Ah battery). I'm not sure how reliable that source is.
ludi wrote:Kind of hard to know what the question is asking. Is this a traditional lead acid battery? If so, is it a sealed type, or vented? Is it for a vehicle application, a solar application, something else? Are you trying to store it between use seasons? Is the storage area being kept in a reasonable temperature range? Etc.
DiMaestro wrote:The amperage of the charger determines just how fast a battery charges.
If this is for long term storage? A trickle Charger will work.
DiMaestro wrote:Deep cycles need warmth.
meerkt wrote:@ludi
Plain car batteries. The immediate one I want it for is basic lead-acid. No need to add water.
It's currently very depleted. 5V unloaded, 3V connected in the car (alarm system?).
ludi wrote:The plates are likely sulfated, it won't come back.
just brew it! wrote:So are chargers with a "desulfation" feature a form of snake oil?
Captain Ned wrote:Let me guess. Left it on the concrete garage floor for a year or so without an insulator between it and the floor. Classic car battery death cause.
just brew it! wrote:ludi wrote:The plates are likely sulfated, it won't come back.
So are chargers with a "desulfation" feature a form of snake oil?
Captain Ned wrote:Let me guess. Left it on the concrete garage floor for a year or so without an insulator between it and the floor. Classic car battery death cause.
meerkt wrote:DiMaestro wrote:The amperage of the charger determines just how fast a battery charges.
The question is, ignoring charge time, any reason a low-amp charger won't do just as well?
For example, this 1A charger spec sheet says: "Battery Capacity: Up to 30Ah, maintains all battery sizes". It could be interpreted as suggesting it's "wrong" to use on >30Ah batteries. Or the charts here. For common car battery sizes, the low-amp chargers are labeled "recommended for maintenance only".If this is for long term storage? A trickle Charger will work.
Not storage. Occasional use when the car's unused or little used for a while.DiMaestro wrote:Deep cycles need warmth.
Warmth?
@ludi
Plain car batteries. The immediate one I want it for is basic lead-acid. No need to add water.
It's currently very depleted. 5V unloaded, 3V connected in the car (alarm system?).
DiMaestro wrote:MeerKT - deep cycle batteries are particular about their heat range. They live/store better when they live in a warmer climate. I know it sounds goofy, but this is what my Interstate Battery dealer told me years ago - and while it may be incorrect information, it will surely allow the battery to live longer.
ludi wrote:DiMaestro wrote:MeerKT - deep cycle batteries are particular about their heat range. They live/store better when they live in a warmer climate. I know it sounds goofy, but this is what my Interstate Battery dealer told me years ago - and while it may be incorrect information, it will surely allow the battery to live longer.
Uhm...not exactly:
https://www.trojanbattery.com/pdf/WP_DeepCycleBatteryStorage_0512.pdf
Without getting into the many corner cases, a pretty good rule of thumb with most chemical batteries is that they store best when cool and work best when warm, and hate extreme temperatures either way. Since it's impossible to satisfy all those conditions at once, lifespan can be all over the map depending on application.
meerkt wrote:BTW, right after disconnection the battery was 5V, a day later 8V, now 9V.
meerkt wrote:I imagined it's something of the sort. Never scrutinized a battery like I did this one, so it's the first time I noticed.
Anyway, after a full charge of some 20 hours, 13.1V.
I let it sit for a day, 13.0V (unloaded).
30 mins of city driving including 3-4 starts, I think it was 12.8V (loaded, car off).
I let it sit for an hour, 12.9V.
Not sure what's the actual capacity now. I'll keep a close watch the next few weeks.