voltage drop

[tlaffourtit]

how much voltage drop is normal for a agm 12v battery or any battery if it is fully charged and connected to nothing?

[MEXICOWANDERER]

full_mosey wrote:

MEXICOWANDERER wrote:
Don, the Lifeline factory manual claims a 31 rated at 110 ampere hours can safely swallow a 500 ampere charge rate. This is what is giving me the willies with those cheapowatts, not a misprint here, the text reads five hundred amperes, 500% of 20 ampere hour rate,

Isn't that is where a temp-comp charger is needed? Doesn't that allow the charger to automatically monitor battery temp and control Voltage?

Why would there be any need for 'the willies' whith an automatic temp-comp charger?

Optima says their batteries can be charged with unliminted current at 15.6V so long as the battery is held under 125F until the charge rate reaches 1A. Isn't that a prescription for a temp-comp charger? What that says to me is that if the temp reaches 125F, the charger should automatically reduce Volts to maintain 125F and that would determine the actual current limit.

HTH;
John

John I hate to admit this but a temperature compensated charging device that can restore a 31 Lifeline to full charge in 2-hours is out of my league. The first of the ordinals is to recharge the battery - fast. This is not elective. When the power goes off -again- after 2 hours, that may be "it" for the day. Maybe 2-days. Again, when I am at home this is not an issue. When I am "here" and my generator is a 2,000 mile drive, or when I am in a hotel room, then things become sensitive. I am thinking of an audible temperature alarm to be pasted onto one of the battery posts. The CheapOWatts cannot be driven in excess of 350 watts. So this leaves me with no choice but to use "enough" 22 dollar units to saturate the battery to 14.2 volts instantly. This will keep the per unit wattage under the maximum tolerated wattage. Yes I could use a MeanWell. And after 2 hours end up with a battery not charged. There are times when 90% battery depletion is going to occur. As long as I can use the BiPAP this does not pose a problem. I do not appreciate the effects of atrial fibrillation. Cannot drive, and hard to impossible to walk.

Yep, this is a tough row to hoe, but the famous quote from my cowboy uncle keeps coming to mind: "Sonny, ya gotta be smarter than the problem"

[tlaffourtit]

i'll drain them some and recharge and see what happens.

[landyacht318]

Thanks for posting PENN's fully charged resting OCV response. I'd not worry about the 0.02v low reading, your DMM could easily be out that much.

[tlaffourtit]

Saturday 12.81 12.81 12.81 12.81 12.82 12.82 12.82 12.82
Monday 12.76 12.76 12.77 12.76 12.82 12.78 12.78 12.78
the first four batteries are new, the last four are 22 months old. I also received an answer back from penn about the voltage levels.

Tim,
A 12V monobloc considered to be at a full state of charge should be 12.8 volts or higher after it has sat ocv for 24 hours.

Thanks

Graig Lecher
UPS Sales – Technical Support
Reserve Power

East Penn Manufacturing Co.
102 Deka Rd., Lyon Station, PA 19536
Ph. 610.682.3263 x3306 Fax. 610.682.0891
Direct Ph. 610.682.3150 x3306
Cell. 484.650.0062

[full_mosey]

MEXICOWANDERER wrote:
Don, the Lifeline factory manual claims a 31 rated at 110 ampere hours can safely swallow a 500 ampere charge rate. This is what is giving me the willies with those cheapowatts, not a misprint here, the text reads five hundred amperes, 500% of 20 ampere hour rate,

Isn't that is where a temp-comp charger is needed? Doesn't that allow the charger to automatically monitor battery temp and control Voltage?

Why would there be any need for 'the willies' whith an automatic temp-comp charger?

Optima says their batteries can be charged with unliminted current at 15.6V so long as the battery is held under 125F until the charge rate reaches 1A. Isn't that a prescription for a temp-comp charger? What that says to me is that if the temp reaches 125F, the charger should automatically reduce Volts to maintain 125F and that would determine the actual current limit.

HTH;
John

[hershey]

Actually, your getting a much better at idle voltage than I ever achieved. Above the norm. Relax and enjoy.

[pianotuna]

Hi Mex,

Thanks for the correction. It truly is an amazing rate of charge.

[MEXICOWANDERER]

Don, the Lifeline factory manual claims a 31 rated at 110 ampere hours can safely swallow a 500 ampere charge rate. This is what is giving me the willies with those cheapowatts, not a misprint here, the text reads five hundred amperes, 500% of 20 ampere hour rate,

[pianotuna]

Hi Gau,

For example how much Antimony is in the paste. That affects gassing voltage and charging voltage

Or if it is Calcium (usually a hybrid type). That means less depth of charge.

Is the electrolyte tropicalized? That means a lower specific gravity for fully charged.

There are probably hundreds of variants on the above. So contact the maker and find out what charging routine is best for your battery.

Lifeline can be "hit" with up to C x 3, so a 100 amp hour battery can be charged at 300 amps. Most other AGM's would not survive.

Gau 8 wrote:

pianotuna wrote:
Hi,

Do you mean agm battery?

Self discharge can be as little as 1% per month or as great as 1% per day. It depends on the chemistry that the battery maker is using.

How does the chemistry vary? They are all lead/acid batteries.

[tlaffourtit]

norm is 25-35, but a few days in the teens, once in awhile single digits. we only need to worry about the winters for 2 more years, then if plans work out we shouldn't be here in the winters any more.

[time2roll]

#2 looks better in Summer and maybe #3 in Winter assuming no temperature compensation.
How cold does it get in Jersey?

[tlaffourtit]

AIMS Power www.aimscorp.net
Switch setting Description Boost / Vdc Float / Vdc
0 Charger Off
1 Gel USA 14.0 13.7
2 AGM 1 14.1 13.4
3 AGM 2 14.6 13.7
4 Sealed lead acid 14.4 13.6
5 Gel EURO 14.4 13.8
6 Open lead acid 14.8 13.3
7 Calcium 15.1 13.6
8 De-sulphation 15.5 (4 Hours then Off)
9 Not use

i am using switch 2 agm 1
after reading the deka page 11 I might want to use switch 3 agm 2

[tlaffourtit]

smkettner wrote:
That system works fine. Check that absorption and float voltages are not more that 0.1 too high.

I do not know about the absorption but the float voltage is .1 below. so i'm guessing that is ok?

[time2roll]

That system works fine. Check that absorption and float voltages are not more that 0.1 too high.