Sealed lead 12v 7Ah alarm battery swelling

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Old 08-01-17, 06:29 PM
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Sealed lead 12v 7Ah alarm battery swelling

I have 2 business alarm boxes using sealed lead 7v, 12Ah batteries as a backup when there is power loss. One was installed in late 2013. A different box was installed in 2015 also using the same spec battery but a different brand. The newer one has swelled up on one end on the side. My perception is the newer battery is a cheap Chinese brand and quality is the reason why it swelled. But I also read that overcharging can cause this. What do you think?
 
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Old 08-01-17, 06:56 PM
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Thread moved to Alarm Forum.
 
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Old 08-01-17, 07:03 PM
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Yeah the quality of the SLA/AGM batteries is just not there anymore unfortunately

Also I have never heard of a 7V battery did you mean 6V?

The battery case usually has a range printed for Cycle or Standby use.

I believe you want your charger to fall within the range for Standby Use.

Cycle use I think means that you would discharge the battery (In a flashlight for example) and then immediately recharge it.

Standby use means the battery is on charge most of the time and is only used in a power outage as your alarm system uses only uses the battery as a backup
 
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Old 08-01-17, 09:13 PM
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I corrected the title to reflect the proper battery type.

It's unusual to see a battery that new swell up. I've seen it many times with batteries usually at least five years old. That's not to say it can't happen with an inferior battery.

I'd recommend changing the battery and check the battery voltage a day after it's been on charge. It should be around 13.2vdc and not above 13.8vdc connected to alarm.
 
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Old 08-01-17, 09:37 PM
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What's a reasonable charging current going from the panel to the battery during normal AC-powered operation of a typical alarm system? I was seeing from 400-500 mA with my NX-6V2. Seems a bit high...
 
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Old 08-01-17, 11:23 PM
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It could be that high to start but it should drop down to much lower than that.

Most alarm panels use constant voltage charging thru a resistor which means the charging current should drop to close to 0 at full charge.

An older battery could draw an excess of power.
 
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Old 08-01-17, 11:39 PM
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Hmm.

My "smart" charger shows the battery charges up A-OK. But it's still pulling REAL hard on the board, close to an amp when first connected, then dropping quickly to around half an amp, then gradually dropping to settle in the 350 mA range. Looks like I'm due for a new battery (and a good look at my charger). Any recommendations as to replacement battery brand and/or model?

Thanks as always for the guidance.
 
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Old 08-02-17, 12:09 AM
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We sometimes go thru cases of batteries in a week. Power Sonic is meh.
We used to only use Yuasu batteries. YUASA-NP7-12F2. Even those aren't like they used to be anymore but they last the longest.
 
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Old 08-02-17, 12:52 AM
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The bulging but rather new battery is a Tysonic. The non bulging one is a 2013 installed Yuasa. I don't really care about the cost of the battery - both will be replaced. What I care about is the electronics associated with the alarm is not overcharging the battery. Being a layperson its would I read online as a possible cause. For example, the Yuasa UK site says they don't warranty bulges as its not caused by manufacturing defects. Tysonic seems to be an off brand based on research. My alarm company denied ever putting it in but later said yes we may have used them episodically. My guess is they know its a f ed product but didn't want to admit it. Anyone familiar with Tysonic?
 
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Old 08-02-17, 12:59 AM
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At the present time the bulk of lead acid battery production is coming from China and Viet Nam with the big push to move most of it to Viet Nam.
There are a lot of no-name batteries probably coming from the same factory.
 
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Old 08-02-17, 03:38 AM
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Just to be clear: Any battery that is swelling needs to be disconnected and replaced, period. If you can't replace it immediately, it _still_ needs to be disconnected. Don't leave a swelling battery on a charger.

A 12V 7Ah battery that has already been charged up should not be drawing several hundred mA. There are two usual causes for overcharging:
(1) The battery has one or more cells shorted so that its working voltage is less than normal. Less voltage in the battery means that the charger pushes more current through the battery and heats it up. You didn't mention it, but I'm betting the battery is warm/hot to the touch. (In future, mention details like that.)

To test, test the battery WITH CHARGER DISCONNECTED. It may or may not read ~13+ volts right after disconnection, but within hours will drop below 12V if a cell is shot.

(2) The charger is malfunctioning and charging at a voltage over ~13.8VDC and overcharging the battery.
After disconnecting battery, test Open Circuit Voltage of the panel's battery leads (Voltage with nothing connected except meter). If it reads more than 13.8v, then it's overcharging.
If it's reading about 13.8VDC, then the cause of overcharging was probably a shot battery cell and your panel is okay.
 
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Old 08-02-17, 03:42 AM
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The average lifespan of these batteries, these days, is 3-5 years, with most showing significant degradation at the 3 year mark. They are making them cheaper; and your charger is probably OK.
 
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Old 08-02-17, 08:04 AM
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Thanks for the info, CO. I'll do the checks you suggest and post back the results for anyone interested. My external charger wasn't heating up the battery at all. And I wouldn't let the panel charge it long enough to warm it up because the output transistor was getting really hot and I didn't want to lose the board (again). I did try running the board (no sensors, 1 bridged zone, 1 keypad) on battery power. It ran for maybe a minute with Ready and Service lit (siren trouble) then crapped out with Fire rapidly flickering, Service still lit, and keypad unresponsive.

To Ron and PJ, I'm off to snag a new battery. I'll look for a Yuasa (I remember they came in Honda motorcycles way back when).
 
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Old 08-02-17, 12:49 PM
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williakz, you need to learn how not to hijack someone else's thread. You basically took over my thread and unapologetically which is flat out f rude. Have some manners.
 
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Old 08-02-17, 01:01 PM
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Thanks guys and CO on the tips. I touched the battery and it did not feel warm. Not like you would normally feel from say a router or some transformers. Will check or have someone check the voltage. I have a cheap multimeter but scared of getting electrocuted as far as the panel and battery. Something to worry about?
 
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Old 08-02-17, 02:03 PM
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Sorry, PN. I thought the discussion was generally about 12V lead acid batteries for alarm system backup.

You had a battery problem; I had a battery problem. The experts on batteries were on hand and strewing their pearls of wisdom before swine (i.e. advising novices). Seemed a better place to put my battery-related issues than in a separate thread right on top of yours where the pros would likely have pointed me to this one or even pointed you to mine, making your mild case of getting lane-jumped, NOT hijacked, even worse. Sorry again for the ruffled feathers.
 
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Old 08-02-17, 04:39 PM
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Everything inside the alarm control box is either 16VAC or 12VAC (and power limited). It's safer than your car's electrical system.

It's actually a good thing for people with similar issues to share a thread; it saves all of us volunteers the hassle of duplicating responses...
 
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Old 08-03-17, 11:14 AM
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Williakz, OK no harm no foul. Its all good now.
Folks, here is a picture of a multimeter I got as a freebie. How do I know its properly calibrated. Ive set it at DCV 20 and used it to test flashlight batteries. For D sized (1.5 volt) batteries, if it reads close to 1.5 I keep them otherwise I toss if below 1 volt. This was based on a YouTube video but I donít know exactly what DCV 20 means. It should read zero at start?
For the alarm batteries, so while disconnected from the system, I should set the multimeter at which setting?
More importantly, for the alarm itself, which setting should I use to test the power level its sending out to charge the battery? Inside the alarm box, there is an on/off switch which I plan to leave on to perform the multimeter test. The alarm itself will be on test mode.
 
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Old 08-03-17, 06:04 PM
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A fully charged battery, off the charger, will read about 13-13.4 volts, with no load. The true test of an alarm battery is to disconnect ac power and test it with the alarm system loading it. If it stays above 12.4 Volts, it's in at least OK shape (that's essentially what the alarm system does automatically once a day).

In any case, deformation of the battery casing is a clear warning sign that it's on borrowed time.
 
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Old 08-03-17, 10:49 PM
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I donít know exactly what DCV 20 means.
It is the maximum DC voltage the meter will read when the switch is in that position. In reality rather than read 20 volts the meter is much more likely to read 19.999 whenever a voltage in excess of that figure is connected across the test leads. Depending on the meter it might display several hyphens (-------) or several zeros or even the latest baseball scores. Never knowingly connect the meter to a higher voltage range without FIRST setting the switch to a higher maximum voltage setting.

Use this 20 volt range for most testing in the alarm panel.
 
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