Lithium UPS, continued

[kelpdiver]

In this week's earlier thread on UPS battery replacements, I highlighted that the lithium (LFP) based home batteries offer UPS functionality with a much greater capacity and lifespan. But the minimum entry size I was aware of was $450/1kwh, or about 5x what you get on a Cyberpower or APC 1500W unit.

The same brand I'm familiar is now taking preorders for the Oukitel P800 - with is a 512 wh batter with 800W AC output, for $279. It weighs 13 lbs. In contrast, that Cyberpower CP1500PFCLCD runs close to the same price, is 200wh, will run 500W for whole minutes, and weighs in at 25lb. And those batteries will be replaced at least once.

Oukitel does seem to be changing their specs to read EPS (emergency power supply) rather than UPS, likely because it does not do the same level on line conditioning. I just picked up a portable oscilloscope so I can examine the output more closely. Nonetheless, I've been running PCs and QNAPs, along with my network routers/switches, for 3 years now on their products.

 

[BobKnDP]

I see that APC and Cyberpower both sell lithium ion based UPSes. At prices in the thousands of dollars. I don't see kWh specs, but a Cyperpower 1500VA/1500W unit can deliver full power for 8.7 minutes. (That's about 218Wh.)

No idea what those extra dollars would buy you.

 

[Billiam29]

We all know with our mobile devices that the consensus is usually to charge them only to 80% or so to help keep the battery's overall charge capacity during its lifetime. So if lithium ion UPSs were to ever make it to the consumer level, would it therefore be best to plan for 80% of the rated wH? Would the same hold true for LFP batteries or do they not have the same diminishing charge capacity characteristics as current mainstream lithium ion?

I'm very much talking theoretical here. IMO there's multiple variables at play...both technical and practical...with the charge to 80% thing. So basically if you're a "charge to 80%" kind of person, should you also be a "plan for 80%" person with any sort of litium battery UPS?

 

[Sean Nelson]

We all know with our mobile devices that the consensus is usually to charge them only to 80% or so to help keep the battery's overall charge capacity during its lifetime. So if lithium ion UPSs were to ever make it to the consumer level, would it therefore be best to plan for 80% of the rated wH?

It's smart idea to buy the extra size, but it won't give you any benefit unless the UPS software lets you limit the charge to 80%. For years and years phones couldn't do this, and it's only with the more recent versions of Samsung phones that there's a "Battery Protection" option to limit the maximum charge.

 

[kelpdiver]

I see that APC and Cyberpower both sell lithium ion based UPSes. At prices in the thousands of dollars. I don't see kWh specs, but a Cyperpower 1500VA/1500W unit can deliver full power for 8.7 minutes. (That's about 218Wh.)

No idea what those extra dollars would buy you.

those are models intended for data centers.

 

[kelpdiver]

We all know with our mobile devices that the consensus is usually to charge them only to 80% or so to help keep the battery's overall charge capacity during its lifetime.

For lithium-ion batteries, including the NCA variants. But not for LFP chemistry, which can be charged to 100%. And also is good for a couple thousand more charges. For cars, that fact makes up for the fact that it is can hold less energy per lb.

Though much like iphones these days, the 2kwh model I have in the garage powering the network infrastructure and the primary NAS, its SoC wanders around the 90s, rather than fixing itself at 100.

 

[BobKnDP]

I see that APC and Cyberpower both sell lithium ion based UPSes. At prices in the thousands of dollars. I don't see kWh specs, but a Cyperpower 1500VA/1500W unit can deliver full power for 8.7 minutes. (That's about 218Wh.)

No idea what those extra dollars would buy you.

those are models intended for data centers.

Yeah. Rack mounted.

 

[RDKirk]

In my experience with various applications of rechargeable lithium batteries compared to rechargeable lead acid batteries, it isn't worth it for UPS application.

Real-world benefits of lithium for me over lead-acid:

1. Longer on-shelf charged availability without cell damage.

2. Better recovery after deep discharge.

3. Lighter weight.

All of those make the lithium the choice for, for instance, electronic flash.

But none of those advantages apply for a UPS. Number 2 might apply, but my UPS systems perform a proper equipment shutdown before the battery is deeply discharged.

 

[kelpdiver]

In my experience with various applications of rechargeable lithium batteries compared to rechargeable lead acid batteries, it isn't worth it for UPS application.

Real-world benefits of lithium for me over lead-acid:

1. Longer on-shelf charged availability without cell damage.

2. Better recovery after deep discharge.

3. Lighter weight.

4. 5x the capacity.

5. 3-4x the lifespan

6. Thousands of charge cycles, not dozens

All of those make the lithium the choice for, for instance, electronic flash.

But none of those advantages apply for a UPS. Number 2 might apply, but my UPS systems perform a proper equipment shutdown before the battery is deeply discharged.

If your experience is primarily in data center operations using commercial grade UPS, and the budget to back it, it's probably true. But the consumer experience is a bit different. The functionality of these $250 units (nevermind the $100 ones) is far from reliable, and when the best case scenario is a run time of single digit minutes, only so helpful. And cost matters a lot.

I plug many devices in that do not have auto shutdown protocols, and I would rather keep working through the minor events anyhow. A long time ago, I made use of APC's XL batteries - it was a 200lb stack of lead acid. Was a pain at the end when they had to be disposed off.

Ånd as a bonus, these battery units can be used for road trips.

 

[Eric Carlson]

In my experience with various applications of rechargeable lithium batteries compared to rechargeable lead acid batteries, it isn't worth it for UPS application.

Real-world benefits of lithium for me over lead-acid:

1. Longer on-shelf charged availability without cell damage.

2. Better recovery after deep discharge.

3. Lighter weight.

4. 5x the capacity.

5. 3-4x the lifespan

6. Thousands of charge cycles, not dozens

Yep! #5 is a big deal for a home UPS for me.

 

[Eric Carlson]

Oukitel does seem to be changing their specs to read EPS (emergency power supply) rather than UPS, likely because it does not do the same level on line conditioning. I just picked up a portable oscilloscope so I can examine the output more closely. Nonetheless, I've been running PCs and QNAPs, along with my network routers/switches, for 3 years now on their products.

I have 3 oscilloscopes (2 old-school CRT, and 1 LCD), but no Lithium based power supplies yet. Let us know what you find out.

With my low power computer setup, I could probably get away with a low end $200 Lithium power supply. Granted, that is still more expensive than each of my 3 CyberPower 1500's, not to mention all my other UPS's. But should be reliable for many more years than the legacy UPS's have been.

--
- Eric, http://www.invisiblerobot.com/

 

[RDKirk]

Real-world benefits of lithium for me over lead-acid:

1. Longer on-shelf charged availability without cell damage.

I don't keep mine on the shelf, I put them into use.

2. Better recovery after deep discharge.

I don't let mine discharge deeply. My system shuts down before that happens.

3. Lighter weight.

I don't move mine around.

4. 5x the capacity.

Of those I've compared in my price range, run time at 800 watts is the same...about 30 minutes.

5. 3-4x the lifespan

Lithium batteries in service last 3-5 years, which is as long as my lead-acid batteries last.

6. Thousands of charge cycles, not dozens

I've never completely run down a lead-acid battery...my system shuts itself down properly before that happens.

 

[kelpdiver]

With my low power computer setup, I could probably get away with a low end $200 Lithium power supply. Granted, that is still more expensive than each of my 3 CyberPower 1500's, not to mention all my other UPS's. But should be reliable for many more years than the legacy UPS's have been.

I got my CPs from B&H on a pretty good sale, so I think I paid in the 180 range. But retail price now is 250+, which is the same as these newest offerings.

I replaced the battery on one of mine in the last 2 years, so I'll let that one keep running. The other one - I may try to third party lithium batt replacement, or may just recycle.

 

[kelpdiver]

4. 5x the capacity.

Of those I've compared in my price range, run time at 800 watts is the same...about 30 minutes.

not for same cost.

5. 3-4x the lifespan

Lithium batteries in service last 3-5 years, which is as long as my lead-acid batteries last.

Lithium ion, maybe (doubtful). LFP/LifePo4 - no. They are good for 10+ years.

6. Thousands of charge cycles, not dozens

I've never completely run down a lead-acid battery...my system shuts itself down properly before that happens.

Sure- because you have no choice. I'd rather keep operating. Lithium backup allows for this.

Datacenter power is far more reliable than home power, and has generator backup. The home environment does not. This thread is about people at home.

 

[Eric Carlson]

With my low power computer setup, I could probably get away with a low end $200 Lithium power supply. Granted, that is still more expensive than each of my 3 CyberPower 1500's, not to mention all my other UPS's. But should be reliable for many more years than the legacy UPS's have been.

I got my CPs from B&H on a pretty good sale, so I think I paid in the 180 range. But retail price now is 250+, which is the same as these newest offerings.

I replaced the battery on one of mine in the last 2 years, so I'll let that one keep running. The other one - I may try to third party lithium batt replacement, or may just recycle.

My CP's were less several years ago, some were also from B&H on sale, I have replacement batteries, but some still don't work after the second replacement.

 

[kelpdiver]

My CP's were less several years ago, some were also from B&H on sale, I have replacement batteries, but some still don't work after the second replacement.

I just ordered these a pair of Nermak 12v 12ah lifepo4s for $68. Can get a 7ah pair for 48 to minimize the experiment cost (the CP RB1280 battery is a 12v 8ah unit).

The caveat is that you only get 1A per battery at 120V, so that means 250watts max for the pair.

 

[BobKnDP]

My CP's were less several years ago, some were also from B&H on sale, I have replacement batteries, but some still don't work after the second replacement.

I just ordered these a pair of Nermak 12v 12ah lifepo4s for $68. Can get a 7ah pair for 48 to minimize the experiment cost (the CP RB1280 battery is a 12v 8ah unit).

The caveat is that you only get 1A per battery at 120V, so that means 250watts max for the pair.

This is mostly a curiosity question:

Lithium replacement batteries exist that are compatible with UPSes that were manufactured with lead acid batteries?

In my ignorance, I would have expected the charging circuitry to be different enough to forbid that.

 

[kelpdiver]

I just ordered these a pair of Nermak 12v 12ah lifepo4s for $68. Can get a 7ah pair for 48 to minimize the experiment cost (the CP RB1280 battery is a 12v 8ah unit).

The caveat is that you only get 1A per battery at 120V, so that means 250watts max for the pair.

This is mostly a curiosity question:

Lithium replacement batteries exist that are compatible with UPSes that were manufactured with lead acid batteries?

In my ignorance, I would have expected the charging circuitry to be different enough to forbid that.

APCs come in a huge variety of proprietary battery formats (like Canon cameras), but CyberPower is a bit more likely to use a very common 12V battery format. It is typically in the 7ah to 12ah range and is 5.94 inches long, 2.54" wide, and 3.94" tall. An L shaped pos and neg terminal on two corners on top. Many devices use this standard.

Lead acid is cheap, and recyclable, but has very limited cycle life, is still lead (toxic) so must be handled properly, and heavy. These lithium replacements give 2x the usable capacity for half the weight, and can be recharged 1000s of times instead of dozens to a couple hundred.

But....in UPS form, you won't get 800 or 1000 watts of power typical for a 1500VA UPS. You get 250, and some surge potential to 500. If the use calls for high amps, these drop ins are not the answer. You need go to purpose made lithium solutions. The one I mention at the top is an example.

Now will the UPS understand the battery life? It may well not, as the voltage patterns differ greatly. Lithium holds voltage for most of its life, and then drops off a cliff. Lead acid is more linear. Though this is part of what I'm going to find out with this trial. I'm not pioneering - many have done this swap. But how worthwhile it what I will see. Otherwise, I got CP 1500VA pure sine wave units ready to sell cheap!

 

[Eric Carlson]

My CP's were less several years ago, some were also from B&H on sale, I have replacement batteries, but some still don't work after the second replacement.

I just ordered these a pair of Nermak 12v 12ah lifepo4s for $68. Can get a 7ah pair for 48 to minimize the experiment cost (the CP RB1280 battery is a 12v 8ah unit).

The caveat is that you only get 1A per battery at 120V, so that means 250watts max for the pair.

Please let us know how they work in the long run. I've seen some people say they don't charge well in the cyberpower UPS.