Maintaining a new battery

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Originally Posted By: mv6845
While charging I noticed the battery voltage was 15.5-15.6 volts. Is this high? I'm using a Diehard Fully automated 10 amp charger that goes into maintenance mode once it's full, however once it's full I disconnect it.


It's so high that it could only be in equalization mode. If not left on too long it won't harm a wet cell other than gassing it off which may require a top up. I wouldn't charge at that voltage while the battery is connected to the car for fear of damaging the electronics. Most manufacturers will quote a safe limit these days of somewhere around mid to high 14's.
 
Quote:
I just want to find a way to measure parasitic drain without having to spend hundreds of dollars on a Fluke m/m. smile
I thought you ordered the multi-meter I had recommended. You have to spend $30 to be able to measure parasitic drain.
 
Originally Posted By: Vikas
Quote:
I just want to find a way to measure parasitic drain without having to spend hundreds of dollars on a Fluke m/m. smile
I thought you ordered the multi-meter I had recommended. You have to spend $30 to be able to measure parasitic drain.

I ordered it, but as I'm finding out, that clamp meter is very inaccurate at very low currents (below 0.2A or so).
 
I think 2 years is very short. Anyway you could mount a solar charger on the roof year around? Seems putting it on a charger once a week would be going too long at an under-charged state. I think your once a week 15-20 minute runs proves my point since you have sulfation in the cells.
 
Originally Posted By: Quattro Pete
Originally Posted By: JHZR2
Originally Posted By: Quattro Pete
Originally Posted By: wrcsixeight
Do note the draw can change with a certain amount of time which has passed Very variable depending on the vehicle.

Right, so with that in mind, how do you safely measure it when your multi-meter's 10A lead socket says "max 10 seconds, each 15 minutes?" Another words, they don't want you measuring it for longer than 10 seconds at a time.

I know my car will draw several amps initially when the battery is first connected while the courtesy lights and whatever else is on, and it'll take some 10 minutes before they go out.

Thanks!



Its the time rating of the fuse in there.

I get that. But if it's 10 seconds at 10A, does it mean it's more than 10 seconds at 9A? Is there a formula to calculate that, so that I don't blow the fuse?

I just want to find a way to measure parasitic drain without having to spend hundreds of dollars on a Fluke m/m.
smile.gif




Yes, any reputable manufactrer should be able to provide what is called the I^2t curve for a fuse model.

Page 7-8 here:
http://m.littelfuse.com/~/media/electronics/product_catalogs/littelfuse_fuseology_selection_guide.pdf.pdf

And this document:
http://ep-us.mersen.com/fileadmin/catalo...ent-and-I2t.pdf

Should help.
 
I picked up a Noco G7200 Genius charger this weekend. While charging my battery I've noticed it will range between 13-14.7V. This seems like a much better option than the 15-16V I was seeing with my Diehard automatic charger.
 
Originally Posted By: mv6845
I picked up a Noco G7200 Genius charger this weekend. While charging my battery I've noticed it will range between 13-14.7V.

Sounds about right. Per instructions, it's supposed to go up to 14.5V when on NORM setting and 14.8V when on COLD/AGM setting.

I just topped up my battery (non AGM) with the G7200 with a voltmeter hooked up, and I actually did not see it go up that high, but there are probably many variables that will affect charging voltage rate.
 
Originally Posted By: mv6845
I've also noticed that. My G7200 is showing 13-13.3 right now.

If it's done charging and is now just maintaining it, then that voltage sounds about right.
 
13.3 float voltage is OK down to about 60f Much colder and float voltage should be higher.

it should be noted if one just drove their vehicle, then hooked up their smart charger, it is possible and likely the charger will see the surface charge voltage, think the battery is full, and never seek absorption voltage.

In such instances i always recommend dropping battery voltage to 12.6v or less leaving lights on with engine off, then starting charger, One can even do so with lights still on, then turn off lights.

If battery is pretty close to full, the surface voltage might rebound quickly above 12.8v, and cause the charger not to seek absorption voltage. So either draw it well below 12.6 and start charger quickly, or keep load on batteries then start charger.

You have to be smarter than 'smart' chargers, especially when the battery is somewhat close to full and has been recharged partially, recently.

In really cold temperatures, 13.2v float voltages are too low for a floded battery and much too low for an AGM. I would fully charge and remove charger rather than let it float at too low a voltage for the temperature.
 
Never thought of that. Thanks for the tip. Just went and turn on lights to drop battery voltage and I've got the charger going now. I'll see what the voltage is in a few.
 
With engine off and lights and high beams on what should the voltage drop down to?
 
It would depend on the size of the battery, and how much wattage the high beams are actually drawing at the unknown voltage they are receiving.

I'll guess a new fully charged battery 75Ah/ 600CCA battery would fall to about 12.5v to 12.6v under the 15 to 18 amp load, and of course keep dropping the longer the lights are left on.

It is a mini load test that can be used for future comparisions on that same battery as it ages.

https://www.amazon.com/Uni-T-UT210E-Curr...HT4J7CBCEWYAAKF

Clampmeters are good to own when one wants to figure out amperage without opening circuits.

Not familiar with product linked. It is an Example, not a recommendation, I have a different brand.
 
Last edited:
Thanks again. My 600CCA 90AH Duracell 96R dropped to 12.6V after 5 minutes with the high beams on. All seems to be well with the Noco G7200.
 
Those numbers do seem to indicate a healthy fully charged battery. Is that using the voltmeter on the Noco or a handheld DMM? I'd verify them if that is the Noco's displayed voltage. I have an older schumacher whose voltage display was nearly 0.5v out of line with actual. It read high. now the display has failed, but I use one of these on the DC output to see what it is doing, and did so before the display failed.

https://www.google.com/search?q=gt+power...YzcDcQQ_AUIBygC

I modified mine replacing the 12awg with 8awg to handle a constnt 40 amps.

Next time, if there is one, and you have the interest to do so, backprobe the headlight connectors to test their voltage when illuminated, and compare to battery voltage.

I was quite impressed with light output once I reduced voltage drop from nearly 3 volts to just over 0.3 via thicker wiring, a better h4 connector and a relayed harness taking power from alternator (+) stud.
 
Originally Posted By: wrcsixeight
Is that using the voltmeter on the Noco or a handheld DMM? I'd verify them if that is the Noco's displayed voltage.
Must be DMM since the Noco has no voltage display.

Quote:
I have an older schumacher whose voltage display was nearly 0.5v out of line with actual. It read high.
My Solar 2320 reads high as well, but only by about 0.1V.
 
Does anyone leave their Noco battery charger/maintainer hooked up over the weekend? Unit says it can be left hooked up indefinitely and my battery is showing 12.96 volts in float mode.
 
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