battery condition

[powerboatr]

before i go to ford and get them to replace the battery under the 3/36
does anyone else's battery drop to 67% of charge in 4 days?

granted when i parked it friday morning it didnt run long enough to recharge from the start up, but did run long enough to warm up while we did the respot in the driveway with the trailer and stuff in the garage.

so i parked it friday morning, have been in it a few times so the boards cycled and lights normal stuff.
this afternoon i decided to toss the charger on it since it will be sitting all week and possibly most of next week and i wanted it fully charged.
once i had the charger on, it went through the cycle to check voltage and percent of charge and started at 67%
so anyone else notice a 30% drop in state of charge in four days?
i plan to recheck it on weds afternoon to see how far it dropped, if any

 

[bobmbx]

I don't think thats unusual. I've similar experiences with my batteries. Performing a fast charge with the charger will always result in a "less than full charge" as the battery 'settles'. The best way to charge is to use a trickle charge and let it run overnight, if you have that mode on your charger. If not, use the lowest setting for your battery type.

Keep in mind that car batteries are not intended to be 'power supplies'. They are designed to provide large surges of current for short periods of time, like starting the engine. They lose their charge a lot quicker than you think they should.

 

[crector080862]

My truck sets for over a week at a time and it never drops down that low but it is an 07

Sent from my SM-G892A using Tapatalk

 

[powerboatr]

going to let it sit until this friday and see what the rate of charge is. No door openings or other stuff until then.
Could be to much was opened and closed.

 

[stamp11127]

Why not just perform a parasitic draw test and see if there is a load on the electrical system?

 

[powerboatr]

Why not just perform a parasitic draw test and see if there is a load on the electrical system?

Time is my weak link this week. I have medical crap all week. most likely not going to feel like screwing with the car by time i get home. taking wife's edge everywhere so i can sleep on way home or toss a few cookies if i get queasy
I had thought about doing that very thing if i get time later this week. i just thought about the WIFI...is set to be on..surely its not a huge draw?
got to run and get going

 

[Plati]

I've been running various "6Amp charger/trickle charge/voltage" tests on my two batteries for a few years, recently replaced both batteries - have continued to monitor them. When you put a 6A charger on and it says 67% … I don't think I put a lot of faith in that "measurement". Having said that, how long does it take to build up to a full charge? That's more data. Whats the voltage build up to & what is the voltage after 12 hours of resting? If you let it sit for a few days, what does it drop to? Whats the voltage with engine idling? What does the voltage drop to while starting (both before and after the full charge/rest)? I know this is a jumble of information.

There are robust test tools to measure a battery's health, a voltmeter or charger isn't one IMHO. They give an indication not an answer.

Real life example. Fairly new battery in my 2003. I'm certain it was FULLY charged a few weeks ago. I let it sit this past week … resting voltage dropped to 12V, which I felt was low but its just sitting there ... draining the battery. So I drove out & back on the highway for a 30 minute trip. Next day the resting voltage was 12.36 … good! It will drop to 10.2V momentarily during an engine start and then raise to 14.6 by alternator charging. No indications I have any issues with battery or charging system on this vehicle. Plus, I've benchmarked the system so in 3 years I have that to compare it to.

Also, it seems a battery can drop in reserve capacity and not be easily replenished by the charging system. So, when evaluating battery health I always charge it up fully before testing further with my voltmeter.

I'm thinking I may have to change my name to MrBattery

 

[JExpedition07]

These days our vehicles are always running even when they are off. Only can let them sit so long, they never truly sleep. Then count any accessories you have plugged in the 12V outlets. You know I’ve gone on a few brand new vehicle test drives and the battery is dead on the dealer lot from sitting a week or two....that’s embarrassing but happens.

 

[TobyU]

You have to get to know your charger. I have old meter transformer ones and newer transistor digital ones. Usually if the charger does not trickle down to 0 or really close to is and green charged light (most have this) doesn't come on it probably has a bad cell or very sulfated.
My digital one (with reconditioner desulfation mode) will error easily if not a good battery.
It is real time charging amps and fluctuates greatly but starts high and comes down quickly after a few minutes then levels off and slows down to around 9-12 amps for a while then gets into the 3-4s and does slower charge then eventually will say full or error code.
It is kind of like the tester and the auto parts stores but not quite as bad. That machine is their best battery salesperson.
It really errs on the side of "bad battery".

I can tell how weak one is when I put my charger to it.
If it goes over 20 amps or so..it was weak.
If you take a good battery that has been sitting overnight and start car with it and turn it off. One start drain...it will go to less than 9-12 amps and start reducing to 4 quickly.

I bought a used Navigator back in Sept and in had a brand new batt in it.
It went dead 2 times. If I let it sit over 2-3 days it might be dead, it might not.
I figured batt was bad or a drain.
I cleaned the terminals and one was a little dirty but mostly lose.
Not been low since and it sits for weeks without being used sometimes.

 

[powerboatr]

had a few coherent moments tonight and tossed the charger on it,
i had only opened the door, so the running board dropped down.

battery read 12.8 and charger stated 98% charge...so i think i was worried over nothing.
she gets a long run tomorrow back to the docs..
if time permits i will check again tomorrow evening, then its going to sit till next thursday...