Lead acid battery

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JerryR
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Lead acid battery

Post by JerryR » Sun Nov 09, 2003 9:42 am

I was given a 1000V/A UPS, the batteries of which are shot. The unit is old and the mfr(APC) does not support it any more.
The unit is using 2 12v/24AH (YUASA NP24-12B)that as far as I can tell from reading internet posts, are Sealed Lead acid batteries(The electrolyte is absorbed in some kind of glass plates-NOT gel).
The NP24-12B batteries is available, but, including shipping are very expensive.
I am considering replaceing the original batteries with 2 automotive type batteries-they are much cheaper and are available locally.
Aside from the fact that the automotive batt. is larger, is there anything wrong with this approach?,
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ad5mb
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Re: Lead acid battery

Post by ad5mb » Sun Nov 09, 2003 11:08 am

We have about 300 UPSs where I work. They all use sealed garden tractor batteries.<p>The reason for sealed batteries: They don't give off hydrogen gas when they are charging.<p>Unsealed batteries work OK in a car, all kinds of places for the hydrogen to go.<p>Not so fine in a house or office, the hydrogen accumulates, creating a potential Hindenburg.<p>SO: If the batteries are in a well ventilated spot, OK. Indoors: inadvisable

k7elp60
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Re: Lead acid battery

Post by k7elp60 » Sun Nov 09, 2003 1:12 pm

The auto batteries should work okey.<p>Sealed Lead Acid batteries do give off hydrogen.
The advantage to gel-cell type batteries is that the electrolytic is in a gel form and won't leak out, hence they can be installed in any position. All the manufacturers that I am aware of' do not recommend gel-cell batteries being installed in a gas tight enclosure because they do out gas when charging.

desterline
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Re: Lead acid battery

Post by desterline » Sun Nov 09, 2003 2:13 pm

I can add a note about automotive batteries. Typical car batteries (for starting) are not very tolerant of deep discharging. If you discharge a 12v batt to 6 volts and then recharge it, it will only hold about %60 of its previous capacity. Do this a few times and it adds up. Starting applications are designed to use less than %5 of the battery capacity. <p>Marine deep cycle batteries (for electric troling motors, usualy) ARE designed for this kind of service. <p>I agree that they need to be vented. Years ago I had a car battery explode on me (no injury), not the kind of thing I'd like to do again though.<p>-Denny

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Re: Lead acid battery

Post by dyarker » Sun Nov 09, 2003 7:53 pm

Sealed batteries don't leak, even if up-side-down. Do not use automotive batteries, for this and other issues mentioned.<p>For longevity and safety use the same type APC used. A different brand of the same type may be less expensive.
Dale Y

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jollyrgr
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Re: Lead acid battery

Post by jollyrgr » Sun Nov 09, 2003 9:29 pm

I used to use automotive batteries and they work fine. BUT I was always worried about the leaking of electrolyte. <p>But then I started using a "cheap" source of lead acid batteries. And these are available at most department stores, auto parts stores, and even many home improvement centers so shipping is not needed (assuming you have a Wal-Mart, Target, or similar store near you). <p>What you want to get is the portable, rechargeable, automotive jumper box. These come in a number of configurations. Some include voltage inverters, air compressors, and flashlights. You do not need to get real fancy if all you need are the batteries. Just get a booster box with a high Cold Cranking Amps (CCA) but forget about the air compressors and inverters; unless you want these things for other projects.<p>Here is an example of one of these devices:<p>http://www.batterychargers.com/itemlist.cfm?cid=12<p>DO NOT buy one of these at the prices listed on the web site above!!! These prices are way expensive and I only provided the link as an example of the device. If you are in the lower 48 and have any big chain stores in your area, you can find these booster packs for under $30 on sale. There may not be the Schumacher name on the case but the internal batteries are pretty much the same across brands. The link above is just to give you an idea of what these things are, in case you have never seen them before. The batteries inside the Schumacher are listed as 12V 18AH units. This would work fine in your application with a slightly shorter run time; about three forths what you would get with the original 24AH batteries.<p>Do not go for the hype about having to buy APC batteries. I have pulled Yuasa, CSB Battery, and Japan Storarage Battery brands out of APC brand UPS.<p>Another source that is a possibility is the batteries used in children's electric ride on toys. These use 12 volt sealed lead acid batteries and replacement batteries can usually be found in the toy section along side these toys.
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CeaSaR
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Re: Lead acid battery

Post by CeaSaR » Tue Nov 11, 2003 5:52 am

JerryR,<p>I've been receiving quite a few flyers from electronics discounters lately. One that popped up with Gel Cell batteries for sale is AllElectronics. They have a page on their site: http://www.allelectronics.com/cgi-bin/c ... type=store that has quite a few to choose from, though none of your exact specs. One thing they don't say on their site that the paper flyers do say is that a number have been removed from previous equipment ( I believe APC and UPS's were mentioned :D ).<p>Good luck on the repair!
CeaSaR
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JerryR
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Re: Lead acid battery

Post by JerryR » Tue Nov 11, 2003 8:10 am

CeaSar
Thanks for the link to allelectronic, but, like you wrote, none of the batteries come up to specs.
I think that IF I eventually decide to fix it, I will use automotive type batteries, they are cheap and available locally(Shipping is expensive for heavy batteries).
Thank you
JerryR<p>[ November 11, 2003: Message edited by: JerryR ]</p>
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cato
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Re: Lead acid battery

Post by cato » Tue Nov 11, 2003 3:01 pm

Interstate sells (or resells?) at least some Yuasa Batteries (or crosses to Yuasas) for much less than you can find the Yuasas for.

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Joseph
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Re: Lead acid battery

Post by Joseph » Wed Nov 12, 2003 1:23 pm

Jolly Roger, those sound like good ideas as I may need a high capacity battery for an electric bicycle.

k7elp60
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Re: Lead acid battery

Post by k7elp60 » Wed Nov 12, 2003 5:52 pm

I would like to caution idividuals from purchasing used gel-cel batteries because, just because they my be charged, they may not have full capacity.
The accepted prodeeure to tell if the battery is
to full capacity, is to fully charge the battery. Remove the charger, wait 24 hours and do a discharge test. This test involves discharging the battery at a constant prescribed current to the cut-off voltage. This discharge is accurately timed. Since the amp/hour rating of a gel-cel is normally
for a 20 hour rate this can be time consuming. However the same gel-cel battery of full capacity will supply it's rated current for 30 minutes. So this is a simpler and faster test. Resistors are
not suitable for this discharge, as they are fixed in resistance, so as the battery discharges the current also decreases.
I have tested many gel-cell batteries with a homemade load bank that uses a transistor, controlled by an op-amp as the load.<p>As a further note, an idea of the residual capacity of the battery can be determined by looking at the open circuit voltage on the battery terminals in two conditions. 1. 24 hours afer the charge, or 10 minutes after the load is disconnected. I say an idea as for example a 12 volt battery at 50% residual capacity can show between 12.1 and 12.6 volts.<p>So the only true test is a full charge and discharge test as previously mentioned

toejam
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Re: Lead acid battery

Post by toejam » Fri Nov 14, 2003 6:19 am

meci call 800 344 4465
17 amp hr 12 v 7"w3"d6and5/8 h<p>no.140-0094
made for bicycle

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