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Katdaddy

Petal, MS USA

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Posted: 10/27/21 02:01pm Link  |  Quote  |  Print  |  Notify Moderator

pianotuna wrote:

Katdaddy,

90% after sitting idle for 24 hours?


Yes.


Little by little, one travels far - J.R.R. Tolkien
There ain't no surer way to find out whether you like people or hate them than to travel with them. - Mark Twain

Katdaddy

Petal, MS USA

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Posted: 10/27/21 02:04pm Link  |  Quote  |  Print  |  Notify Moderator

2oldman wrote:

Katdaddy wrote:

The solar would show the voltage up to 13.00 during the day and then it would again drop to 12.30 after dark.
What does 'the solar would show' mean? The panel on the controller? During full sun?


The readout on the controller and my volt meter would read 13.00. Never had what I would call full sun. The most input I saw was 48 watts. The batteries read 12.30 when we got there and, with solar each day read 12.30 when we left.

BFL13

Victoria, BC

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Posted: 10/27/21 02:05pm Link  |  Quote  |  Print  |  Notify Moderator

What DC load is on the batts while camping for that 12.3 that is not on at home for that 12.6?

You can't tell "90% charge" with a load on the batts. You can get a voltage but can only guess at the % of capacity, and you have to guess at the capacity too, since it changes with temperature.

Your batts are no doubt sulfated somewhat from lack of time at 14.8v and equalizations to 16v from time to time, so they might have more of a voltage drop under load that batteries in better shape.


1. 1991 Oakland 28DB Class C
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2. 1991 Bighorn 9.5ft Truck Camper on 2003 Chev 2500HD 6.0 Gas
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Gdetrailer

PA

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Posted: 10/27/21 02:16pm Link  |  Quote  |  Print  |  Notify Moderator

Katdaddy wrote:

2oldman wrote:

Katdaddy wrote:

The solar would show the voltage up to 13.00 during the day and then it would again drop to 12.30 after dark.
What does 'the solar would show' mean? The panel on the controller? During full sun?


The readout on the controller and my volt meter would read 13.00. Never had what I would call full sun. The most input I saw was 48 watts. The batteries read 12.30 when we got there and, with solar each day read 12.30 when we left.


Your batteries never got close to 100% "full".

13.00V from your panels was nothing more than trickle charging at the max.

Generally your battery needs to see 13.2V just to keep up with the internal self discharge of the batteries.

To effectively cause some meaningful charging to happen you need voltages of 13.8-14.4V.

Flooded Lead Acid batteries typically will have a fully charged resting voltage of 12.8V give or take .1V..

12.3V? Yeah, you have discharged or wornout batteries and your solar is not enough to fully charge them..

Katdaddy

Petal, MS USA

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Posted: 10/27/21 03:22pm Link  |  Quote  |  Print  |  Notify Moderator

BFL13 wrote:

What DC load is on the batts while camping for that 12.3 that is not on at home for that 12.6?

You can't tell "90% charge" with a load on the batts. You can get a voltage but can only guess at the % of capacity, and you have to guess at the capacity too, since it changes with temperature.

Your batts are no doubt sulfated somewhat from lack of time at 14.8v and equalizations to 16v from time to time, so they might have more of a voltage drop under load that batteries in better shape.


The loads are exactly the same. That is what is confusing me.
I exercise the batteries regularly. I draw them down to around 50% and then apply a 14.8 charge while checking the SG. Equalized right before this trip.

BFL13

Victoria, BC

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Posted: 10/27/21 05:06pm Link  |  Quote  |  Print  |  Notify Moderator

Must be an unknown 12v load when camping that is not on when at home. Not sure what it could be that draws it down 0.3v. Some inverter draw?

Sorry I implied you don't look after your 6s.

Gjac

Milford, CT

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Posted: 10/27/21 05:36pm Link  |  Quote  |  Print  |  Notify Moderator

How did you fully charge your batteries when you were home by solar or a battery charger? A fully charged battery should read more that 90% overnight. Did your son turn on the heat during the night? I assume you had a fairly long ride to get to Cades Cove and your alternator and solar should provide some charging along the way so to be at 70% SOC is a mystery. How many amps does your solar and alternator provide? How long was your drive was it at night? Now that it is home and fully charged I would disconnect the power and see how long it takes to drop to 90%. Then check each cell with a voltmeter or hydrometer and see if one or more cells are bad. I never had good luck with any hydrometer, mine always read 1.375 even in distilled water unless you have a real good one I find the volt meter easier to use. Last question when you measure battery SOC are you looking at a controller reading or using a multi meter at your actual battery posts?

MEXICOWANDERER

las peñas, michoacan, mexico

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Posted: 10/27/21 09:02pm Link  |  Quote  |  Print  |  Notify Moderator

The ambiguity would be found with a hydrometer. There must be a hundred discussions on this forum about hydomerers usage, links, types and brands.

My Samsung cellular goes from 100 to 50% in three hours. Then from 45% to 12% shutdown the next hour. Next to useless.

Go to
Http://www.rollsbatteries.com
Download their battery manual
You have batteries exhibiting classic signs of partial sulfation.

Katdaddy

Petal, MS USA

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Joined: 08/25/2003

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Posted: 10/28/21 08:05am Link  |  Quote  |  Print  |  Notify Moderator

MEXICOWANDERER wrote:

The ambiguity would be found with a hydrometer. There must be a hundred discussions on this forum about hydomerers usage, links, types and brands.

My Samsung cellular goes from 100 to 50% in three hours. Then from 45% to 12% shutdown the next hour. Next to useless.

Go to
Http://www.rollsbatteries.com
Download their battery manual
You have batteries exhibiting classic signs of partial sulfation.

Yes, I have decided that the hydrometer is going with me next year.
On a related note, I gave a cheaper hydrometer. I know that you have recommended a Francis Freas. I’m having trouble finding where to purchase one. Can anyone help with a website or store?

pianotuna

Regina, SK, Canada

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Joined: 12/18/2004

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Posted: 10/28/21 11:16am Link  |  Quote  |  Print  |  Notify Moderator

You can order one here:

https://www.bradyinstruments.com/product........y-hydrometer-set-wcorrection-thermometer


Regards, Don
My ride is a 28 foot Class C, 256 watts solar, soon to have SiO2 batteries, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.

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