Replacing UPS lead acid batt w LiFePO4

[mtts]

Ahh... so hypothetically if I run the 1/4" spade connectors outside the UPS to a... idk 50ah LFPo, I should be fine. Because it will have a much larger BMS with a high AH C-rate draw capability. Any suggestions?

https://www.amazon.com/BtrPower-Lithium-LiFePO4-Battery-Application/dp/B0C64Z96DB

BtrPower 12V 8Ah Lithium LiFePO4 Battery • 5000+ Deep Cycle LiFePO4 Battery • with 10A BMS​

Here, this one has a BMS that says it's capable of 10 amps. I can't imagine a mini-UPS like the Belkin (36w peak) drawing more than that on a self-test. It's nearly twice as much as the 6ah LFPo that didn't work.

Oh and it can do 20 amps for 5 seconds!

 

[mtts]

Sad, to say, there must be something internal that the Belkin does not like about LFPo. Even the 20amp/5sec battery generated a tone alarm as soon as i plugged it in. The alarm goes on, then off, then on, and switching the rear main power ON, gives the all-lights on the front, then 'On Battery'. An error condition, as the UPS is plugged into the wall during the testing.

Will keep this battery, as I'll do another UPS test with it.

 

[DIYrich]

Sad, to say, there must be something internal that the Belkin does not like about LFPo. Even the 20amp/5sec battery generated a tone alarm as soon as i plugged it in. The alarm goes on, then off, then on, and switching the rear main power ON, gives the all-lights on the front, then 'On Battery'. An error condition, as the UPS is plugged into the wall during the testing.

Will keep this battery, as I'll do another UPS test with it.

I have an APC UPS, and have a Victron 48v to 12v voltage regulator. The APC complains about the power (I disabled the battery alarm), but runs fine. I'm thinking it is doing some battery test, and the solid voltage from the regulator is failing the test. I tried upping the voltage (14v) from the Victron, but no difference.

BTW: The purpose of powering the UPS from the 48v battery is for when the inverter goes off-line (like when it reboots after a firmware update). The UPS powers the internet, and everything stays connected.

 

[mtts]

Wow victron makes a 48-12? I have a 40amp output 13.8 that can input a wide range of voltage. Something like 40-60v. It was perhaps $25. All potted, you've seen them online.

A router and most 12v equipment will run directly from that 13.8v. No need for an inverter to 120vac then a wall wart adapter.

For ASUS routers that use 19v, there is a booster to that. Existing cabin wiring loom was 12v. One item uses 48v, but the mfg said the upper limit was 51v, so i fed it with a booster.

If the all-in-one takes a dump, the DC system continues to power the internet. A further security would be a 12v100ah LFPo kept on charge, but the 13.8 acts as a regulator - voltage is always a consistent value.


ASIN B01MYMVGSU it's 30 amp. Wonder if two could be put in parallel for 60a.

 

[DIYrich]

Wow victron makes a 48-12? I have a 40amp output 13.8 that can input a wide range of voltage. Something like 40-60v. It was perhaps $25. All potted, you've seen them online.

Victron Orion-TR. Lots of options for voltage conversion and amps.

A router and most 12v equipment will run directly from that 13.8v. No need for an inverter to 120vac then a wall wart adapter.

AC backup the DC (when I take down the battery for maintenance) or DC backup the AC (current setup). Easier to keep the AC power supplies for each of the devices. Also, mix of 5v and 12v devices.

 

[Delmar]

Here, this one has a BMS that says it's capable of 10 amps. I can't imagine a mini-UPS like the Belkin (36w peak) drawing more than that on a self-test. It's nearly twice as much as the 6ah LFPo that didn't work.

My APC SUA1000XL has an inline fuse on the 24V 18AH pair rated 100A. They obviously expect some amp draw.

My 48V SUA3000XL inline fuse is rated 140A.

 

[mtts]

Thanks for the fuse ratings and battery voltages!

The Belkin is more like 45VA, if we use a formula based on the SUA1000XL 1000VA/800W rating. The Belkin's output is 12.4v DC, measured, as it's meant to back-up a single router that draws maybe 15 watts, so there isn't the same issue with AC power factor.

140 amps x ~50v = 7,000 watts. Or a fuse rated at passing a number that is 233% of the power of the VA rating.

Using the most generous number, of 45VA: 45 * 2.33 / 13 = 8.07 amp fuse. So...8 amps. It's going to self-test at a threshold below that. Even if it's 10 amps, the battery can do 20 for 5 seconds.

SUA1000XL: 100a x ~25v = 2,500, or 2.5 of the VA. 45 x 2.5 / 13, is 8.65 amps.

The formula used is: fuse rating in amps x nominal realistic battery voltage ÷ VA rating = x. X is a ratio of the VA rating, to give us an idea of how much power the designers would allow to pass out of the batteries, for a surge, for instance. Derived by using two known good UPS designs and their fuse ratings.

 

[Delmar]

The Belkin is more like 45VA....

Just noticed the Belkin model number, great minds think alike. I have been running a Harbor Fright 35AH for years with no battery issues. I am also surprised about your amp draw, running mine from a 5A fuse and have never popped.

EDIT: and I load the battery well with LED lights, case fan, USB charging and power port for a Surface tablet car charger. From the Belkin regulated output power my fiber modem and wireless router. I get around 10+hours runtime from the 35AH, but never needed to push to the limit. The Belkin is a steal for its capabilities.

 

[mtts]

Just noticed the Belkin model number, great minds think alike. I have been running a Harbor Fright 35AH for years with no battery issues. I am also surprised about your amp draw, running mine from a 5A fuse and have never popped.

That will be my next step!

 

[mtts]

It's got to do something with the internal resistance differences between LA and LFPo?

 

[rjg13]

Hey all,

New here and registered specifically for this thread. I currently have a SUA2200RMXL3U APC UPS. I purchased an ECO-WORTHY 48V 50Ah LiFePo4 battery pack from amazon. I'm wondering how to deal with the float voltage/sla charge profile on the UPS. From my understanding, the lead acid charge profile will keep a small amount of current flowing to the battery once it gets to the set charge voltage, whereas a LiFePo4 charger shuts down completely. How do I account for this with this battery? Should the BMS in this battery protect against over charging the cells using the SLA charge profile that is in the UPS?

 

[Delmar]

New here and registered specifically for this thread. I currently have a SUA2200RMXL3U APC UPS. I purchased an ECO-WORTHY 48V 50Ah LiFePo4 battery pack from amazon. I'm wondering how to deal with the float voltage/sla charge profile on the UPS. From my understanding, the lead acid charge profile will keep a small amount of current flowing to the battery once it gets to the set charge voltage, whereas a LiFePo4 charger shuts down completely. How do I account for this with this battery? Should the BMS in this battery protect against over charging the cells using the SLA charge profile that is in the UPS?

Welcome to the forum, and thanks for bringing your UPS fetish with you. I am also eagerly awaiting for an answer to your question as I just melted the terminal off one of the FLA batteries in my golf cart. I want to replace with Lithium while still using my FLA wall charger.

 

[Battery Help]

I have an Eaton 9PX1500RTN UPS for over two years which I made the Eaton UPS fan mod to put two Noctua fans connected by a 4-pin y-cable (the NF-A8 FLX in the back and the NF-A6x25 FLX in the front using the Ultra-Low-Noise Adaptor (U.L.N.A.) on both fans (one adaptor per fan) and the temperature never exceeds 28°C in the UPS and you can't hear the fans at all, it's like 10 dBA or 13 dBA).

I'm starting to have problems with the battery because the battery charge lasts almost half of what it did when it was new, it discharges faster and I had planned to change the 4 original batteries connected in series for 4 new 12V 9Ah GEL batteries (GLB 12-9 by Chicago Digital Power), but I found this thread and I have some questions about LiFePO4 batteries that I would like help answering.

This battery I have found:
• XZNY 12V 12Ah LiFePO4 Battery (12 amps of max. continuous discharge)

1. Can I connect 4 x 12V 12Ah LiFePO4 batteries in series to get 48V 12Ah so that I can use them in my UPS?

2. The maximum consumption I have is between 500W to 600W when I am working and a minimum between 20W at idle or 70W when I am browsing (which is most of the time), I only have a modem, a router with WiFi 6 (in another room), two monitors and a computer connected to the UPS, nothing else, will the 4 x 12V 12Ah LiFePO4 batteries connected in series to get 48V 12Ah support the maximum consumption load 500W to 600W or I will have problems and the LiFePO4 batteries and the UPS will burn out?

3. If I replace the SLA batteries with LiFePO4 batteries in the Eaton UPS, do I have to change the Battery charge mode setting from ABM cycling (default) to Constant charge or does it not matter?
Information about ABM:
• Eaton ABM technology
• ABM technology and battery testing in Eaton UPS products
• How to Properly Charge LiFePO4 Battery? - Sunon Battery

4. Do I have to disable the "Deep Disch. protect." setting that is enabled by default?
User guide: If set to Yes, the UPS automatically prevents battery from deep discharge by adapting end of back-up time voltage threshold. Warranty void if set to No. This setting is recommended to avoid damaging the battery. Warranty is void if deep discharge protection is disabled.

5. Will the UPS detect the new 12Ah battery capacity automatically or do I have to change it using the Eaton SetUPS program?

6. Could you recommend 4 x 12V 10Ah (or more Ah) LiFePO4 batteries with the same form factor and size as 12V 9Ah SLA batteries?

Thank you.

 

[rjg13]

I have an Eaton 9PX1500RTN UPS for over two years which I made the Eaton UPS fan mod to put two Noctua fans connected by a y-cable (the NF-A8 FLX in the back and the NF-A6x25 FLX in the front using the Ultra-Low-Noise Adaptor (U.L.N.A.) on both fans (one adaptor per fan) and the temperature never rises above 28 degrees on the UPS and you can't hear the fans at all, like 10 to 13 dBa).

I'm starting to have problems with the battery because the battery charge lasts almost half of what it did when it was new, it discharges faster and I had planned to change the 4 original batteries connected in series for 4 new 12V 9Ah gel batteries (GLB 12-9 by Chicago Digital Power), but I found this thread and I have some questions about LiFePO4 batteries that I would like help answering.

1. Can I connect 4 x 12V 10Ah LiFePO4 batteries in series to get 48V 10Ah so that I can use them in my UPS?

2. The maximum consumption I have is between 500w to 600w when I am working and a minimum between 20w at idle or 70w when I am browsing (which is most of the time), I only have a modem, a router with WiFi 6 (in another room), two monitors and a computer connected to the UPS, nothing else, will the 4 x 12V 10Ah LiFePO4 batteries connected in series to get 48V 10Ah support the maximum consumption load 500w to 600w or I will have problems and the LiFePO4 batteries and the UPS will burn out?

3. If I replace the acid batteries with LiFePO4 batteries in the Eaton UPS, do I have to change the Battery charge mode setting from ABM cycling (default) to Constant charge or does it not matter?

4. Could you recommend 4 x 12V 10Ah LiFePO4 batteries that are the same size as the standard 12V 9Ah acid or gel batteries?

These are some that I have found:
• NERMAK 12V 10Ah LiFePO4 Battery
• XZNY 12V 10Ah LiFePO4 Battery
• ExpertPower 12V 10Ah LiFePO4 Battery

Thank you.

The issue you will run into is finding LFP batteries that can handle the required current. At 600w and 48v, you are looking at 12.5 amps of continuous discharge. Those batteries you listed are spec'd at 10a of continous discharge, and you also need a bit of margin on top of it.

 

[Battery Help]

The issue you will run into is finding LFP batteries that can handle the required current. At 600w and 48v, you are looking at 12.5 amps of continuous discharge. Those batteries you listed are spec'd at 10a of continous discharge, and you also need a bit of margin on top of it.

Thank you for responding and I hope you (or someone else) can also help me to solve the other questions in my previous post, especially questions number 3 and 4.

Then I need 12v LiFePO4 batteries that support at least a maximum continuous discharge of 12.5 amps each.
• 600W / 48V = 12.5A (minimum I need)

I have found these batteries that exceed the maximum continuous discharge that I need and have the same form factor and size as 12V 9Ah SLA batteries:
• Amped Outdoors 12V 15Ah LiFePO4 Battery (15 amps of max. continuous discharge)
• Dakota Lithium 12V 10Ah LiFePO4 Battery (20 amps of max. continuous discharge)
• BOTKU 12V 10Ah LiFePO4 Battery (20 amps of max. continuous discharge)

Spoiler: Battery Reviews

Amped Outdoors 12V 15Ah LiFePO4 Battery Review

Dakota Lithium 12V 10Ah LiFePO4 Battery Review

 

[rjg13]

Thank you for responding and I hope you (or someone else) can also help me to solve the other questions in my previous post, especially questions number 3 and 4.

Then I need 12v LiFePO4 batteries that support at least a maximum continuous discharge of 12.5 amps each.
• 600W / 48V = 12.5A (minimum I need)

I have found these batteries that exceed the maximum continuous discharge that I need and have the same form factor and size as 12V 9Ah SLA batteries:
• Amped Outdoors 12V 15Ah LiFePO4 Battery (15 amps of max. continuous discharge)
• Dakota Lithium 12V 10Ah LiFePO4 Battery (20 amps of max. continuous discharge)
• BOTKU 12V 10Ah LiFePO4 Battery (20 amps of max. continuous discharge)

Spoiler: Battery Reviews

Amped Outdoors 12V 15Ah LiFePO4 Battery Review

Dakota Lithium 12V 10Ah LiFePO4 Battery Review

For question 3 I can't give you a solid answer. It's most likely going to depend on what type of battery you buy and what it has for a BMS in it. Remember, we are trying to use LFP batteries with a SLA charger. If you can't adjust the float voltage on your UPS, then you run the risk of messing up your lfp batteries. Eaton ABM MAY work, but I'm not familiar with it and without testing I can't really say.

For question 4, the lfp BMS should have undervoltage protection, so the deep discharge protection doesn't matter. The UPS is thinking that it is dealing with a battery, literally a battery, not a battery behind a BMS.

Just out of curiosity, is there a reason you are looking for SLA sized LFP batteries? You could buy a large 48v pack. Mine should be here tomorrow so I can see if it works.

 

[LeonLu]

Anyone went with route of Portable Power Station with ups/ pass through function?

Don't laugh... I own a Golab R300. It even even have "pure sine"!!.....I'm using it for a outdoor IP camera. I like the capacity..299wat, 600w peak. Low side I think these ran for $120?

I place it onto a smart switch, main power to unit get cut off for 2 hours each day. It discharge a few percent. Then recharge it. This is how I prevent from always being full... Just in case.

Due to headache and all that. I didn't bother with a larger UPS+ lifepo4 conversation.

I don't mine not having unit beep when surge happen ( this unit is a backup for my rental property) I don't want them to call me up for "beeping sounds"

Probably zero surge protection. But my house has a "whole house surge protector" and I toss a cheap one onto the unit too.

I'll probably won't do Golab again, their unit are buggy. Sometime time life drops, all ports don't work, lcd number show random things. Which I been lucky enough for it to self fix.

Another idea is UPS into a portal battery bank?

 

[rjg13]

I got the Eco-Worthy LFP battery in today. It's hooked up to the UPS and it works. I still need some direction on what I should set the float voltage too. Not sure if I should go above or below. Right now my mind is to get the battery to 80% charge and float it there, but not sure how it will work.