UPS Replace the entire unit or just the batteries?

Hardware Hub Other Hardware
1

So my batteries in my ups are just starting to fail. Found out while I currently have no power to the house and having to do this post on a windows laptop.

The UPS in question is a cyber power cp1500avrlcd. It’s 5 - 6 years old so right about when the batteries are due for replacement. The unit is in good condition both working and cosmetically.

So if this were you would you risk just replacing the batteries or go full bore and replace the whole unit?

If just the batteries what ones and same chemistry or upgraded?

If whole hog replacement what make and model?

Thanks in advance!

2

Absolutely replace the batteries. The unit should be designed for this, and if it’s not, throw it out and get one that is. You should be able to get batteries identical in form and chemistry, open the unit and drop them in.

Take care not to accidentally create any electrical connections between metal parts while working on the unit, it’s not high voltage but it can be high amperage - this can be LETHAL. Disconnect the existing batteries immediately to reduce risk. Use appropriate personal protective equipment (insulated tools at the very least).

Probably not advisable if this is your first time working on electronics in this way, but very doable for someone with a modicum of competence.

6 Likes
3

I’ve worked on electronics / computers for years so I do understand the risks. The reminder is never a bad thing!

I usually would go with like for like replacements but in todays age of lithium this and that vs lead acid I was curious if making the conversion was worth it or not and if so is it just the batteries I need to replace?

4

Can’t speak from personal experience about changing chemistry, but my amateur understanding is that lead acid chargers behave differently to lithium batteries and are not a drop in replacement, so I would avoid. Bet someone smarter than me could do it though.

4 Likes
5

This situation, is a muuuch better fit for more reliable, heavier used lead acid, rather than denser, lighter lithium

I would not go lithium for something constantly cycling power like a UPS, unless it needed to be mobile, like a phone, or a car.

Even then, is no real viabl option… (Yet)

On the other hand, I don’t use UPS’s for my main rig; just surge protectors.

I expect I will loose work if a power cut vere happens, but it’s been over a dacafe here near an airport, and only 1 power cut of maybe 10 minutes/ half an hour?

6

There are lithium battery packs designed to be a drop in replacement for 12v lead acid, using the same shell and contacts. That can be used in theory. They have a BMS so the cells are protected.

Usually lithium phosphate type, which is the safer and high charge discharge cycle count type of lithium chemistry. Some ups manufacturers are already using that.
https://www.eaton.com/us/en-us/products/backup-power-ups-surge-it-power-distribution/backup-power-ups/lithium-ion-batteries-/eaton-9-series-lithium-ion-batteries.html

I dont have much experience besides that though, and if you dont need to think about it you should just get the same battery type with same specs

1 Like
7

new $189, replacement battery $49 I can replace the battery three times for the price of one. Usually batteries replaced last about 12-18 months with no real degredation, and on my 4 UPS’s I’ve replace 3 batteries in 6 years. I vote get a battery and swap it. aaronzsh said it best

1 Like
8

I’ve been running the older model of the OP’s unit for almost three years after modifying it to run with LFP batteries.

The main issue with LFP vs SLA packs is that the former have much lower continous drain current. The OEM 12V 7Ah batteries can easily deliver 50A continously. Even with the much larger 20AH Lithium-Iron packs I use, they’re only rated for a few seconds with that load. Either the internal protection circuit (BMS) will disconnect/fail, or the cells become damaged.

The good news is that the charging circuit in this UPS has a maximum voltage of 27.6V, so it’s very unlikely to damage a 24V LFP pack. The disadvantage is that not only will the lithium batteries never get fully charged, but the cells are likely to drift as well.

Lithium batteries aren’t like lead-acid, they’re not self-balancing. They use so-called “top-balancing” where an internal circuit monitors each cell and switches a bleed resitor to keep

their voltages in check.

For LFP this ends up being around 3.55V x 8 cells or 28.4V. So at the very least, you’d have to periodically disconnect the batteries from the UPS, and use a charger with the right programming. Oh, and if you use two 12V batteries instead of one 24V battery like I do, you’ll also have to charge each one seperately, since one pack will switch off before the other fully charges.

Finally, I’ll also mention that a poorly designed UPS might cause BMS failure, leading to a pack overcharging and possibly venting. (Look at the melted batteries in some APC units.)

Eventually I intend to bypass the original charging circuit in my UPS, and replace it with a small LFP charger in the future. If anyone knows of an inexpensive model, please let me know. :slight_smile:

1 Like
9

Thank you for the information!

1 Like
10

I think with the information provided I’ll just replace the batteries for the time being with the same type and see what models / units people come up with for the life / lipo options for @daveMeister

1 Like
11

On the one hand, I have serveral 15+ year old single and dual 12V7A battery UPSes throughout the house. A couple being “pure sine wave” versions (those tend to need replacing more often?!). Various brands.

I also had two large RM2200VA APC UPSes in the rack. So I advocated for always replacing batteries…

…Until the APC popped, like a shotgun sound, it’s capacitors. Besides the cats pissing themselves, it took out one of the three servers with a voltage spike and PSU, mobo, memory, and M.2 fried. The 10x HDDs seemed ok. Maybe the backplane had some power protections.

Two weeks later, the other APC RM2200 popped the same shotgun sound. This time though, only my (replaceable) router was connected. And it was fine.

Point is: I’m not so sure about replacing batteries in 10+ year old units. I think that’s my cutoff now.

12

Yea …….. use to be an apc guy. They never felt right for build quality and when they did fail it was something with the internals of the board vs the batteries.

It’s also the reason I’m asking about replacing batteries vs the whole unit as this is my first cyberpower unit.

Another couple of questions I have is: Do they make a bigger capacity battery that will drop into the unit I have and will the unit handle it without modification?

13

No, only rackmount UPSs are designed to handle larger packs. These freestanding units are designed to run just long enough for a safe shutdown. There’s a tiny 40mm fan that just circulates the air inside.

IMG_2487
IMG_24871920×1440 726 KB

Also, without better ventilation the charging circuit will probably fail with a larger pack. I remember that the temperture dropped something like 30C after drilling a couple dozen holes into the case.

If you leave it unplugged for a few minutes with the batteries disconnected, you can safely peek inside. Just like with a PSU or M/B, you can check for bulging/leaking capacitors and any signs of overheated or discolored components.

I’ve had pretty good luck with the Cyberpower units, but consumer equipment like this seems to be all over the place in build quality. If you can get good batteries for less than half the price of the UPS, I’d say go for it, otherwise, I’d start looking for a replacement.

My dad ended up replacing his old APC UPS with one of those small Bluetti powerstations in UPS mode. I helped him test it, and his desktop seems to run fine with it. I’m still not completely sold on the idea, because they’re not explicitly designed for 24/7 operation. I am fairly certain that with most of these powerstations, that the LFP cells will outlast the electronics by a large margin.

14

If the UPS is still meeting the need, I would just replace the batteries with the same FLA ones and be done with it.

I don’t think adding run time by adding batteries to an UPS not designed for it is a good idea. In the photo above, you can see the “heat sinks” are just thermal mass, no fins, and very little cooling. They are not designed to run long. Basically a few minutes until the system is shutdown.

Also on a CyberPower 1500 I fixed, the batteries went bad, and put a larger load on the battery charging circuit. The voltage regulator is under that bit of L shaped metal above. It ended up burning out. When I did the math on it, it was basically being pushed to the limit to charge even good batteries back up. Adding more batteries would make this worse.

The entire thing is built down to a price and a need. To handle a power outage a few times a year, and just run for a few minutes at load.

Most power stations are designed to be run at full load until the batteries are dead. Then quickly charge back up, and do this often. At this day and age, I would really look at using a power station with a UPS function over just a UPS, especially if it’s going to be used often.

2 Likes
15

A 12v 9ah should fit. I upgraded a similar unit with 9 ah batteries.

16

Thank you for the information. I generally don’t see many power outages in my area. Maybe 3 to 5 times a year as an average not including major storms as I will actively shut down my ups for those systems coming thru . Normal line fluctuation is maybe 1-2 times a year will buzz for a second but not long enough for the ups to tone out. Last year being an exception……… 5 new homes went in a 1/2 mile down the road and connected to the same grid section I’m on.

Definitely will look into a power station vs an ups.

17

A couple of issues to consider with Lead Acid batteries. After Y2K a large number of smart APC UPS systems were auctioned off and I bought six at ~$20 - $25 for the house.

PCs, network, TVs and even an audio amplifier had their own UPS. These UPS have been slowly dying over the last 5 years and only 3 of the 6 still survive. Over the years they have had multiple battery changes.

I’m also running a variety of CyberPower UPS. A couple of OLS3000E, a 1U rack plus some BRICs LCD. The first CyberPower UPS I bought was a Smart App Office OR1500ERM1U in May 2023. Therefore none have been in service long enough to require battery replacement but real soon now …

Bottom line is feed your UPS with batteries when a battery self test fails.

In the same form factor (i.e. dimensions) you maybe offered different AmpHour (AHr) ratings from different manufactrurers. At one stage I was offered batteries with a higher AHr rating at a cheaper price. Looked like a win-win. Catch was they had traded higher AHr capacity for a shorter life. May be they had more lead and less liquid, or some design/manufacturing compromise or issue. At the time we had moved to the suburbs and the AHr capacity was irrelevant for mains transient outages. I can assure you that a longer battery service life is desirable. Therefore the highest AHr rating may not always be the best solution.

Regarding manufacturer’s specifications:-

Yuasa Battery Brochure

In a UPS the batteries spend most of their time in Float Mode so the Float Service Life is of interest. It may be worthwhile to spend more for a battery that will provide extended Float Service Life.

The reported AHr will vary with the discharge rate. Hopefully all manufacturers wiil use the 20 Hour discharge rate.

Different ranges of batteries are optimised for different applications. For example:-

Auxilary Equipment and Mobility Range

These applications rate service life purely on discharge cycles. If you compare 50% DoD cycles the REC series are rated over 600 cycles while the NP range just over 400 cycles but the specifications don’t provide the float life of the REC series. So ensure you retailer knows you are looking for batteries for a UPS i.e. float service.

Notice the NP series, 100% Depth of Discharge (DoD) plot on Typical Cyclic Service Life in Relation to Depth of Discharge. This may be significant in a very small number of cases. If you expect frequent, long mains outages that will exhaust the batteries then this can shorten typical service life. We used to live in a rural location in the foothills and suffered multiple outages per season from trees, bushfires, and weather. Even then there were probably not enough outages over the years to kill the batteries.

The other issues is the battery terminal design as different manufacturers will vary these. I don’t know CyberPower internals to know how much clearance is available.

2 Likes
18

I built my own recently. I just got an inverter/charger combo and add a 12v 400ah battery to it. Which should be enough to run my network stack for 24+ hours.

4 Likes
19

This statement is ripe for a blog post or forum post with more detailed information. :slight_smile:

Heavy warning obviously. But those of us with AC experience would be comfortable building and isolating such a device.

I’ll be more than happy to design the 3D printable case.

1 Like
20

I recommend replacing with the same type of battery. As has been mentioned, a larger battery-pack will mean the inverter will work longer, and that can cause overheating and possibly fire…

But yeah, replacing batteries > replacing unit. I’ve had my APC rack-UPS for near 10 years now (bought second hand), and I think it’s on its third or fourth battery-replacement now.

2 Likes