AH test for used Deep cycle Batts

[glennestanford]

Hello everyone, I have a opportunity to purchase some used tornado alarm change out batts, how would be the best way to test them for usefulness? Especially capacity (AH)? That's all I know until I go to look and check them out, any constructive comments/advice or procedure's is greatly appreaciated.
Thanks

[PNjunction]

Of course we're going to say that's a bad idea, but if you REALLY want constructive here it is:

It is going to cost you either way. I hate sounding like a broken record, but here it is again...

Get a Tecmate-Optimate 6 charger to test each cell with. For the time being, stated capacity means nothing if they are totally sulfated, have shorted cells, bulged out from positive plate growth and the like.

The Optimate will try it's best to revive such abuse, but just as important, TEST them during and after charge and give you an indication of whether you have gotten extremely lucky, or need to haul the whole lot to the recycler.

There are manual methods for determining capacity, but right now that is not important until you can determine if these are trash or not. Many dumb chargers, and even some so-called smart ones, will just balk or time out - possibly prematurely. Also consider a Battery-Minder charger, but the Optimate is a bit more informative for the general consumer and maybe a bit more available worldwide.

[glennestanford]

Thanks PNjunction for your informative reply, it is my understanding that these batts are changed yearly so that improves my chances, I won't have the opportunity to charge and che k at the man's place of business, but he said he would allow me to sort through, test and choose, I don't need but a couple or so for the small system I and going to put together so maybe I can come home with A couple of good ones. He receives these 3-4 times a year and sells out quick to boaters ect. thanks for your help.

[Sunking]

Measure AH with a light bulb and clock. Really any known load will work.

If they are 12 volt batteries, use a 12 volt light of at least 10 to 30 watts as it sounds like you have a small battery. Connect them to the battery, and start a timer. Best to use a volt meter to determine when they are discharged to 10.5 volts. Note time.

AH = Watts of bulb x hours in decimal format / Battery voltage

Example: 20 watt x 6.25 hours / 12 volts = 10.14 AH

FWIW .25 hours = 15 minutes.

[PNjunction]

Ok, I guess the best bet than is to just take a voltmeter with you, and pick the ones with the highest terminal voltage and cross fingers.

I'm not really sure what a tornado alarm battery is, but I'm assuming it is a generic little agm. If so, those too could be "high rate" models, that will only last about a year if they are drained consistently to 50% DOD. Maybe that's why he's swapping them out yearly - dunno'.

[glennestanford]

A tornado alarm is a community coverage LOUD alarm in the event that a tornado warning has been issued for your area, I would assume that the batts are of at least 75 AH being loss of standing on charge awaiting a signal to go into alarm. I reside in the country and there is one located at our vol FD bld. and as the crow flies it is about 2-2-1/4 miles away and can be heard if outdoors when it is in alarm, there is a lot of trees between us, I have been told it has been reported to be heard 5 miles away. The seller has pics on a local FB page and by looking, they appear to be 12 volt and sized around the auto/truck batt. I will see if I can locate a pic and post if possible.

[glennestanford]

eBay




New message from: ayanhu81 Top Rated Seller(22,004YellowShooting Star)




hi,my dear friend
i am so sorry,i just a small seller,not profesional,please you see my item description,so sorry for inconvenice to you
have a nice day
best regards



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Dear glen_stanf,

hi,my dear friend
i am so sorry,i just a small seller,not profesional,please you see my item description,so sorry for inconvenice to you
have a nice day
best regards


- ayanhu81









Your previous message



I am searching for a device that will allow me to check/test old deep cycle batteries for how much life is left in them, AH in particular, will this tester be portable to take in the field and check/test deep cycle batteries and provide data in a short period of time? These batteries may be low on AH life and that would need to be ascertained while at certain installations and help make the decision as whether to replace or attempt to recondition. If your meter can do this do you make one that has a 200 + AH ceiling, not knowing what the AH rating of these batteries will be before literally arriving at different locations to test. Thanks









寄件者： glen_stanf
收件者： ayanhu81
主旨： Details about item: glen_stanf sent a message about Capacity Tester Indicator coulometer for 8V-50V 48V Lithium / Lead-acid Battery #181427862194
送出日期： Nov-26-15 18:52:46 PST




Dear ayanhu81,

I am searching for a device that will allow me to check/test old deep cycle batteries for how much life is left in them, AH in particular, will this tester be portable to take in the field and check/test deep cycle batteries and provide data in a short period of time? These batteries may be low on AH life and that would need to be ascertained while at certain installations and help make the decision as whether to replace or attempt to recondition. If your meter can do this do you make one that has a 200 + AH ceiling, not knowing what the AH rating of these batteries will be before literally arriving at different locations to test. Thanks


- glen_stanf











Capacity Tester Indicator coulometer for 8V-50V 48V Lithium / Lead-acid Battery





Capacity Tester Indicator coulomet

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I hope this is viewable/legible, it is a copy of a question and reply from seller on Ebay regarding this subject on a meter that claims to measure AH and more, the pic did not show up but item can be looked up by user/item number. If this little meter will do as I hope it will, then this may be my answer, Please some of you intelligent, versed people take a look and comment/advise, sorry for it being duplicated. Thanks