Solved UPS replacement battery - 6x cell or lead- acid?

[teckneeculler]

I have a Dynamix UPS unit - model SafeGuard750VA. The battery - a lead-acid MHB, model MS9-12 12V9Ah/20HR - has failed.
One supplier has offered me a lead-acid replacement battery but another has offered me a 'solid state' 6-cell unit for about the same price. He says it's the 'modern' replacement for lead-acid.
Is this correct? Are there any advantages of one type over the other?

 

[Digital Life]

I would try to get the exact same battery that's in it now, Different types of batteries have different charging characteristics and may not be compatible with the charging voltage/amps that that unit uses.

I would defiantly not trust the word of one supplier

 

[teckneeculler]

Thanks, DL, I'll go with the Lead-Acid type.

 

[file3456]

Just want to add here that if you want to try and augment your UPS, check out a so-called "battery generator." I say so-called because they don't "generate" anything. It's like a big lithium ion battery UPS. (Not sure if you live in the U.S. or what ever) https://www.amazon.com/s?k=battery+generator&sprefix=battery+generator%2Caps%2C185&ref=nb_sb_noss

What you do is when the UPS kicks in and it takes longer than a minute or two for mains power to go back on, plug your UPS into that thing.

If you can get one that uses LiFePO4 (simply put, Lithium iron) that in my opinion would be the better way to go. Apparently, a lithium iron battery is not so prone to burst or cause fire. Also, they're super light weight ( I own one) and I can charge this 12V, 6 AH battery in a relatively short time. I can't remember what that was now. Could have been 45 minutes or an hour and forty five minutes. They do need a special charger. I use this battery for a "police scanner" (radio receiver) and it'll last on average 22 hours with the volume on high. Add two in parallel for 44 hours! That's one day 19 hours (close to 20 hours) of continuous use for my scanner!

Anyway, these so-called battery generators can be charged via solar as well.

 

[teckneeculler]

Thanks. Those unit are available here but they're overkill for me at $NZ500-600. My UPS's are there simply to give us a warning that the power has gone off, and we should close down our systems. I must check as to how I'm powering my modem-router. If it's the only unit still powered by the UPS, I guess it'll run for quite some time, so we could at least use our laptops.

 

[Megahertz07]

I have replaced a UPS lead acid battery with a car battery. The 12V9Ah/20HR is a 9Ah. A small car battery can be 45Ah and can even cost less.

 

[teckneeculler]

I have replaced a UPS lead acid battery with a car battery. The 12V9Ah/20HR is a 9Ah. A small car battery can be 45Ah and can even cost less.

That's an interesting thought. Does a UPS automatically accept a 'foreign' battery like this?

 

[Megahertz07]

That's an interesting thought. Does a UPS automatically accept a 'foreign' battery like this?

Normally yes. Must be a sealed battery.

 

[TechnoMage2016]

UPS Replacement Battery

I've been using the APC brand of UPS's for about as long as they have been on the market. (30+ years)
This particular brand comes with one Gell-Cell battery. The battery is sealed and cannot be serviced, only replaced.

So for many years, when the original battery in a UPS (I have five of them in my house) fails, I remove it and replace it with a Full Service Lead Acid battery, like you would use in a Garden Tractor or Riding Lawn Mower. I get them at Walmart.
I protect the UPS itself, from fire, by putting an In-Line fuse between the battery and the UPS.

This is the APC UPS that I use to back up my main computer system. With this battery,
I can get over an hour of run time.

I have one OLD 600 VA, UPS that uses two Car Batteries, for HOURS of run time, not minutes.
Last time I tested it, it ran on these batteries for 8 hours, before I ended the test and shut it down.

However, I tried this trick on a different brand of UPS, (a Trip-Lite) one day, and it would not accept the External, Lead Acid battery.
So, I just threw that UPS away and bought another APC brand UPS.

Good Luck, Mate!

 

[teckneeculler]

Megahertz07, thanks again.

TechnoMage2016: What a great setup, you've got me thinking.
My daughter's 2005 Toyota Camry is due for a new battery. The old one is a regular medium size 12V car battery, I'm not sure of its other specs. Do you think I could connect her old battery to my Dynamix 750VA UPS? The car battery is obviously ailing and if the car isn't started every 4-5 days it gets pretty weak. But connected to a UPS would get it a constant charge, no?

 

[Megahertz07]

Don't use a car dying battery to replace a UPS dead battery.
Normally when you replace a car battery you leave the old one to be recycled.

 

[TechnoMage2016]

Megahertz07, thanks again. TechnoMage2016: What a great setup, you've got me thinking. My daughter's 2005 Toyota Camry is due for a new battery. The old one is a regular medium size 12V car battery, I'm not sure of its other specs. Do you think I could connect her old battery to my Dynamix 750VA UPS? The car battery is obviously ailing and if the car isn't started every 4-5 days it gets pretty weak. But connected to a UPS would get it a constant charge, no?

Maybe it's just a personal thing, but I wouldn't want to put anything but a known GOOD (new) battery on a UPS.
And I'd prefer a 'Full Maintenance' battery, with removable caps over the cells, so I can check on each cell on a regular schedule, to make sure it's not running low on water. (full maintenance batteries are all I ever use)
If there is a cell that's low on Fluid, I will bring it back up to full with Distilled water.
It's just a little thing I do.....called, Maintenance.

PS: Since a UPS battery is on 'Charge' 24x7, they WILL loose water over time, and should be checked regularly.
If you uncap a cell and look in with a bright light, and see the top of the plates, the fluid level is LOW and should be
brought back up to the full line, with distilled water, ASAP!

 

[file3456]

That's an interesting thought. Does a UPS automatically accept a 'foreign' battery like this?

Unless you're handy at that stuff, I wouldn't mess with it. One wrong wiring harness, fuse, etc and your insurance won't pay out due to fire.

Read this: batteries - Extending the backup runtime of a UPS with an external car battery - Electrical Engineering Stack Exchange


Another thing about car batteries is that they're not meant for drain and recharge all the time. YOU really need to design the circuit used with a float charger that cuts off and doesn't constantly charge, a commercial/industrial grade relay, proper fuse, etc.

You're far better with LiFePO batteries, but they're expensive. Reason why is because the cut off is low than other batteries. Just looking at my notes here for my small 6Ah LiFePO battery, the cut off voltage for my scanner ("police scanner") was 9.4 volts. That's with the volume st to high and a fare amount of voice traffic. 3.3 watts/275 mA is the typical drain for this radio.


PS:

The "gassing off" of a battery is flammable and poisonous hydrogen sulfide.

It can be produced by the broken battery or by heat production when overcharging it.

Your Car’s Battery Can Be Deadly | Strange Chemistry

 

[teckneeculler]

Megahertz07:
TechnoMage016:
F22 Simpilot:
Guys, thanks again for your helpful advice, probably saved me from burning down my house .
Especially when a replacement UPS battery was just $NZ59. And now I see that my PC parts supplier has a new offering for $NZ42.
Cheers all