left-over 6V 10amp batteries

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  #1  
Old 06-22-13, 01:28 PM
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left-over 6V 10amp batteries

At my workplace we recently replaced some rather out-dated emergency light fixtures that don't use these type/size of lead-acid batteries: 6v 10amp Sealed lead acid (VRLA) Batteries
So I have three of the used batteries which are left over after the replacement. I checked them with a meter and they still read out strong at 6V plus.
Before just taking them to the battery disposal drop-off place at the hardware store, since we have absolutely no use for them otherwise now, I was wondering if anyone might have a comment how I could put these to any other practical use for the time being anyway, until they die. any ideas? thanks
 
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Old 06-22-13, 01:51 PM
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Try to test them under load. Almost any battery can show good voltage at rest.
 
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Old 06-22-13, 01:57 PM
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Try to test them under load. Almost any battery can show good voltage at rest.
Hmm. What's a good way to do that? We already threw out the old fixtures. I know they test auto batteries at the auto parts place and can tell you the condition under load, but those are 12V car batteries.
 
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Old 06-22-13, 02:42 PM
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Older cars and tractors used 6 volt batteries so at least some testers will be dual voltage. You could try a small 12 volt bulb such as used for dome lights in series with your meter.
 
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Old 06-22-13, 03:35 PM
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Hi sgull,
if they test good I would think that with all of the interest in solar collectors someone would like to play with them. I'm not sure how suitable they would be, but I get questioned a lot from people wanting to learn.

Just a thought, stay cool .
Bud
 
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Old 06-22-13, 04:07 PM
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Older cars and tractors used 6 volt batteries so at least some testers will be dual voltage.
Based on that reply (quoted above) I took the batteries to the auto parts place and they indeed have a dual voltage tester. The guy put up to 30 amps load on the batteries, and they still tested "fine" he said.
 
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Old 06-22-13, 04:12 PM
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if they test good I would think that with all of the interest in solar collectors someone would like to play with them
Yeah that's something to keep in mind. Thanks Bud.
 
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Old 06-23-13, 12:34 AM
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They make perfect doorstops too.

If they are over three years old they won't be good for much.....especially any heavy load use.
 
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Old 06-23-13, 05:34 AM
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Sounds like the makings for a portable usb power source.

Find an enclosure - plastic file carrier, plastic lunchbox...
Pair two batteries to make 12v.
Wire in car cigarette lighter outlet and plug in the car charger for your phone-
voila portable phone charger!

Could also be a mobile power source for a usb webcam, from usb-spy pen, or just an old cell phone used as wireless webcam (nannycam, or garden cam, or swimming pool cam)

And of course, take along camping, to power all those weird usb gadgets

uv water purifier


flashlight


electric shaver


beverage warmer/cooler



single can mini-fridge


and of course fan, electric blanket, foot warmers, humidifier, air purifier..
 

Last edited by Hal_S; 06-23-13 at 05:58 AM.
  #10  
Old 06-23-13, 08:35 AM
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Those batteries can be pretty handy like said.
I am going to connect a 12v, 7ah one to the radio in my truck camper.
It will let me kill the power to the radio without loosing the settings.

You can not tell the capacity of a deep cycle battery by using a load test.
There are meters for estimating AH capacity but they are quite expensive.
A sure way is to connect a load similar to what you will be placing on the battery and timing how long it takes to go from about 12.8v to 11.8 v which is the voltage when considered fully depleted.

If you take the voltage to much lower than 11.8 or so the battery will be damaged.
Many low voltage cut off settings on things like inverters and such cut off between 10.5 and 11 volts.

Here is a chart for estimating the AH based on how fast you discharge the battery based on 12 volts.

A chart to estimate the battery state of charge after resting.



This chart is a bit conservative.
I use 12.8 as 100% charge and 11.8 as 0% charge and try not to go less than 25% depleted to maximize life which would be to never let go below 12.0 volts.
 
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Old 06-23-13, 09:02 AM
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GregH,
It seems in your reply you are providing the numbers etc. in reference to 12V battery(s) and not 6V of this type as I have. Although surely the info would still generally apply the same way except of course the numbers I suppose.
 
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Old 06-23-13, 09:08 AM
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Thanks for all the ideas/replies. That's more than enough for me to consider for the time being. I'll post back if any further developments.
 
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Old 06-23-13, 09:19 AM
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The chart in the post gives both 12 and 6 volt state of charge ratings.

I couldn't quickly find the discharge ratings for a 6 volt battery but assume you will series connect them for a 12 volt device.
You would likely connect the two six volt batteries in series and charge at 12 volts.

The discharge rating in the link would then apply because two 6 volt 10 AH batteries would give you 12 volts @ 10 AH.
If you connected them in parallel you would have 6 volts @ 20 AH.

Do you get how the AH rating works?
The battery may say "10 AH @ 20 hr rate".
This means if you draw down the battery over 20 hours it will give you 10 AH.
Or, if your load discharges the battery in 1 hour you will get 6.59 AH out of it.

The AH rating is only for the discharge rate stated on the battery.
 
  #14  
Old 06-23-13, 09:43 AM
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GregH,
OK I see. Thanks for clarifying. I'll definitely follow up and reference with the info you provided here should I proceed with further testing/checking. Thanks!
 
  #15  
Old 06-23-13, 11:21 AM
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LED lighting and power to a laptop or small TV when a storm knocks out the power... or your camping (lugging lead acid batteries in a backpack uphill is great cardiovascular conditioning while hiking to the campsite).
 
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Old 06-23-13, 04:17 PM
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And as a last resort I have an old pot and frying pan that are now used for making lead tractor weights.
 
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Old 06-23-13, 04:37 PM
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Too bad Dane.... I have probably a hundred 12v 7ah and 20 6v 4-10ah alarm batteries waiting to go to the recycling depot. A lot of them check good but they are wiped. I would never plan on relying on them for anything.
 
  #18  
Old 06-23-13, 05:04 PM
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I have probably a hundred 12v 7ah and 20 6v 4-10ah alarm batteries waiting to go to the recycling depot. A lot of them check good but they are wiped. I would never plan on relying on them for anything.
Never rely on them for anything?
PJmax:
They make perfect doorstops too.
 
  #19  
Old 06-23-13, 05:15 PM
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And they do.....'cept I don't have that many doors in my castle.
 
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Old 06-23-13, 09:40 PM
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Put on a 5V voltage regulator and they'd be good USB chargers.
 
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