Your exactly right the only issue is due to the larger battery capacity and longer runtime there may be issues with cooling.

You could overstress the sine generator, it is specified for a fixed amount of max time.

@@NavySeal2k Just put a fan on it, it'll be fine.

@@NotoriousPyro Tell me you have no clue about electronics without saying you have no clue about electronics

That for sure. I just didn'thave anythingby hand and as all the casing and other stuff inside was insulated, I thought it's going to do without it. haha. Thanks for the good comment!

Thanks mate! Yeat, the tropics are a permanent concert of noises :)

Yes. 4 cells in series matches the 12V, so if you have a bigger device, which lets say has a 10Ah lead acid battery inside, you can start adding cells in parallel. So you take lets say 2 LiFePo cells, put them in parallel, and connect with the next group of 2 cells in parallel. That is then called a 4s2p pack. You can use as many cells as you have space available. 4s3p, 4s4p, etc....

@@RolandW_DIYEnergy how long does it power the computer after power outage?

@@Middle-Eastt 20 min max. It of course also depends on your power draw. This UPS only has a small battery really...

I got mine from here, but this might only be in Thailand and I didn't see a kit anymore: www.lazada.co.th/products/lifepo4-3270032650-1-set-4-32v-6000-6500mah-i3111984799-s11532539188.html?spm=a2o4m.searchlist.list.63.426c28c9sJmpPw&search=1 You can try this from AliExpress: www.aliexpress.com/item/1005001565728757.html?spm=a2g0o.productlist.0.0.126f2821fEs1dw&algo_pvid=c259103f-55fc-4903-830c-e5b7016dadad&algo_exp_id=c259103f-55fc-4903-830c-e5b7016dadad-18&pdp_ext_f=%7B%22sku_id%22%3A%2212000016612079308%22%7D&pdp_pi=-1%3B20.9%3B-1%3BUSD+17.43%40salePrice%3BUSD%3Bsearch-mainSearch And a BMS board: www.aliexpress.com/item/1005003079938137.html?spm=a2g0o.productlist.0.0.42a57837m56SPy&algo_pvid=232b117b-18fa-435a-bcc3-be409079c064&algo_exp_id=232b117b-18fa-435a-bcc3-be409079c064-0&pdp_ext_f=%7B%22sku_id%22%3A%2212000023953589268%22%7D&pdp_pi=-1%3B1.74%3B-1%3BUSD+1.79%40salePrice%3BUSD%3Bsearch-mainSearch

well, I am here in Thailand. They are selling this all over SE Asia. You would have to look up Amazon, Ebay or AliExpress, etc if you live in the west...

Hi. Yes, sorry. I think that was one of the last videos of the pre-lapelmic aera. My later videos got an audio upgrade :) Thanks for watching and commenting!

That one has the bigger 7,2 Ah Battery inside, right? You would use the same 32700 LiFePo4 cells but might be able to fit at cells in a 4s2p configuration inside the case. If that wouldn't work, then you might consider to place the battery outside of the UPS as you need the stronger, higher capacity battery pack.

@@RolandW_DIYEnergy Thanks for these configuration suggestions. Yes, it's a 7.0 Ah battery inside. I'll just have to give it a try.

Hi, B+ and P+ are basically the same port on a BMS. On this board they are just connected on the PCB anyways. BMS's typically switch on the negative pole of the battery. You can of course connect your UPS and battery separately via each port if you wish.

I only have 3 indicator LEDs. And I see the green one illuminated always. Can't really say what it going on inside. hehe. But what i have noticed after an extended grid down, if the pack is discharged a bit to much, it will not restart charging. Then I need to bypass the Mosfets of the BMS board to get it going again. But I just think the reason for it is the crappy, cheap BMS board which has a high drop of voltage over the switching circuit.

@@RolandW_DIYEnergy i've been watching this Will Prowse guy on youtube. he has stated you can check battery level with voltage like you do with lead acid. in my experience the charger in the UPS turns on and shuts off based on battery voltage. HOWEVER he has also ranted on cheap/poor quality BMS as well

@@RolandW_DIYEnergy Just use a balancer not a BMS, the UPS will manage low shutoff and the problem is gone. Upper voltage of the LIFEPO4 is higher too, so it should shut off well before the upper limit. Did you check the real capacity because the lead acid battery controll board will shut off before the LIFEPO4s are full.

That means either, that your charging regulator is set a bit to high, or one of the cells is running away and out off balance. Regulator cannot be changed, but if it is a weak cell, it could be fixed by getting a new cell. Did you measure the total voltage and individual cell voltages before it happens and the BMS is shutting off? Or try to top balance cells first

Hi, the UPS is still working. It held up fine during many of our short power interruptions. I do not think that charging characteristics are playing much role for a UPS as the battery is anyways just sitting there fully charged all the time and just used for seconds or minutes at the max

Hehe, good luck. Hope that such a big pack won't blow up the small board :)

@@RolandW_DIYEnergy hopefully my other reply didn't get blocked for linking a forum post with my last big upgrade

@@cdoublejj yes, posts with links are blocked, but i didn't receive it for review as well

From an online shopping platform here in Thailand called Lazada. You would have to look what you can find in your country/region...

The Lifepo4 32600 cells will give you about the same capacity in the same volume as the original lead acid battery, but typically you can discharge LFP deeper without damaging the cells then the LA. So runtime might not be increased, but lifetime will. If you need more runtime, you could go for a LiPo 7s pack built out of high capacity 18650 cells giving you the 24V. Or you might add a few cells in an external battery extension for the LFP.

Lead acid batteries have a voltage drop-off as their state of charge decreases, but that's why the UPS has a large transformer. It takes the declining voltage for the lead acid battery and converts to whatever voltage your electronics need that is plugged into the UPS. LiFePO4 is better because it holds voltage much longer, but anyway the transformer is doing the work to increase the voltage. I think Roland is right...you won't get a lot more capacity unless you build a bigger battery that is not inside the case. This is also a pretty easy project.

The issue with larger battery reserve. You need to charge them back up again.. And being the built in charger in these things have small output. You would spend the next two+ days charging it back up to 100%....Why You would need an external charger with at least 5amps output. That can charge the type of batteries you are using... I would add. If you so chose to use an external battery charger. You have to decouple the batteries from the internal one..As you will burn out the MB on the UPS...

If your running 24 volt that's even better you could have the option of using cobalt cells also. Most power disruptions are intermittent so.etimes just enough to cause a reboot of your equipment ups fix that I use them on all my TVs exc

Hallo. Ich denke schon, dass es genauso bei 24V geht. Also der Laderegler macht keine Probleme. Läuft bei mir jetzt schon fast 2 Jahre so...

@@RolandW_DIYEnergy Super Danke für die Antwort!..Werds einfach probieren mehr als schrotten geht eh nicht .

No no, working perfectly :)

I have bought it online here in Thailand. This stuff is quite easy to get in SE Asia/China. You might have to improvise if you live somewhere in the West or buy a finished LFP 12V replacement battery...

Hi. Replacing the Lead Acid battery with the readymade LFP pack was a good decision and the UPS will work similarly as before. LFP a very close match in voltage to LA. But still, it is not a 100% match. The initial drop in voltage comes from the LFP charge and discharge curve, which is steep at the ends, but very flat in the middle. Thats very normal. Nevertheless, the onboard charging unit of the UPS will handle it just fine. In my UPS I have noticed that the system will shut down a bit sooner than you might expect from the capacity. So, it's probably only about 85% of energy which you can get out of the battery now. I have also noticed that after a full discharge, the UPS control board will not start charging anymore and I have to bypass the Mosfets on the BMS to reset the unit. This is because the BMS is causing a bit of an extra voltage drop, which at the end seems to be a bit out of specs and the UPS needs a bit of a push to do its job again. But anyways, an UPS should just keep your PC alive at a power outage, so that you can safely shut down your computer. Never let the UPS run until it dies itself. A small battery like that will only give you 10-15 minutes of time.

@@RolandW_DIYEnergy Thks Roland. BTW, I have also connected a voltage meter to the battery to know how the voltage is dropping. And Also so that I make sure that I keep the battery within a certain range, so that it does not drop below a certain level. It would also help me to know how fast the Battery is discharging and when is the right time to shut down the computer.

@@mediatrix1111 OK, good idea to use a voltage meter. As said, the voltage will keep steady for most parts of the discharge and then suddenly start to drop quickly at the end of the cycle.

@@RolandW_DIYEnergy Noted. So then I guess I might not have enough time to shut down the computer when the voltage meter starts to show the drop. Cause it will be very fast towards the end. Will have to learn how to work around it by experience. Thks a bunch Roland. It was good to learn this.

@@RolandW_DIYEnergy thanks for a very interesting video. I replaced a lead acid battery with a lifepo4 battery. I ran the ups until it switched off. But after connecting the mains to the ups nothing happened. With the lead acid battery in the ups it would start charging immediately. Is there no way to overcome this please? I cannot afford to let a backup battery run down and not getting charged again. If this is connected to an alarm system then the alarm will trigger every time the power gets restored from the mains. We get a lot of power failures in my country. Usually for 2 hours at a time but lately up to 4 hours

Yes, just use 8 cells in series and a 8s BMS

@@RolandW_DIYEnergy Do I need the BMS if it is a complete battery, that looks like the original lead acid battery? (not cells linked) But two complete similar looking batteries (just lifeP04 types).

@@dermeister314p no, in that case the protection circuit will alread be built into the finished battery pack. but you might get a problem to restart your UPS in case the battery is depleted and the packs are shut down. in that case you will have to jumpstart the ups from outside.

@@RolandW_DIYEnergy thank you, I appreciate the help.

BMS for LiFePo4 cells will disconnect the battery at a high voltage of 3.65V per cell, and low voltage of 2.5V per cell. So for this 4 cell pack, the voltage range is 10-14,6V. This is well inside Lead Acid voltage range of the UPS charger, which as you saw stopped charging at around 13,6V. Where do you get the voltage of 12.6 or 3.15V per cell? I think you misunderstand the term of 'nominal voltage', which is 3.2V for LiFePo4. Nominal voltage is just the average voltage of a cell chemistry's voltage range. It is only used to define cells. For LiPo and NMC it is 3,7V, but the voltage range there is 3.0-4.2V...

@@RolandW_DIYEnergy Thanks for your kind reply .I really appreciate it. Can you answer me some questions ?! I have lead acid battery UPS. I want to connect 18650 cells My BMS charging is written 12.6V Possible output of BMS for example to a 12V fan. Now I want to connect the BMS port to the UPS charging port Is it possible ? After all, about 14 volts will go into the BMS volt input What can you teach me about this? I would be very happy for your detailed answers, it will greatly help. Yes I may not know or do not understand much, for that there are good people (teachers) like you. I thank you on behalf of everyone.

@@user-zg3nb1mk5b OK, now I understand. You want to replace Lead Acid by 18650 laptop cells with Lithium Ion chemistry. Sorry to say, but will not work! LiIon cells are unsuitable to replace Lead Avid in 12V systems due to the incompatible voltage range. You would need 3,5 cells in series. 7s 24V and 14s 48V can be done with LiIon. Please don't do it, its not worth the trouble even with using a buck converter to reduce voltage from the onboard charger, as 3s is to little voltage to keep the UPS running for long enough when discharging. 12V must use LiFePo4 cells!

@@RolandW_DIYEnergy if I have a 48v UPS would you recommend I go with liion or lifepo4? thanks

@@frzen technically you can go with a 14s Lion battery as well. I would prefer LFP cell from the safety standpoint especially when you have the UPS somewhere indoors. It will end up to be a decision on which cells you can get easier, right? LFP packs are bulkier as well.

12,7V LA might be the nominal Voltage. A fully charged LA battery will be close to 14V, while at around 12V it will be close to depleted. LiOn cells only hold a fraction of capacity between 4,0 and 4,2V (maybe 5-10%). Your UPS will shut down before you pack even gets started. It just doesn't work in 3s, while 4s is similarly bad as the cells don't get enough voltage....

(ตัวเมียลบ) Promotion 4 ก้อน แบตเตอรี่ลิเธียม LiFePO4 32650 3.2 v 6000-6500mAh แถมฟรี!!!ตัวยึด 2 ช่อง 4 ชิ้น | s.lazada.co.th/s.3iv2H ฿85.00 -57% | วงจรป้องกันแบตเตอรี่ BMS LiFePo4 3.2V 30A 4S (Peak 56A) บาลานซ์: 58mA ชนิด Common port | s.lazada.co.th/s.3iBBO But I think this is only available for Thai domestic. If you live in another country, please check your preferred online shop for 32650 LiFePo4 cells and a small 4s LiFePo BMS

Yes correct. I would say it's a 80% match. On the high end the UPS will stop charging before LFP is full so there is nothing wrong with that, and on the low end the BMS will typically kick in for protection. It all depends if the solution can fit to your application. If you are only protecting against relatively short grid outages where you don't want your PC die before you have the chance to shut it down safely, then this will still work well. These small UPS's don't have massive run times with the original batteries either. But the LiFePo cells will at least hold up much longer then the Lead Acid ones.

@@RolandW_DIYEnergy Yep, (I don't know the specs of your UPS) a LiFePO4 maximum voltage = 3.65x4 = 14.6Vmax with Vnom = 12.8V and minimum cut-off = 10.0Vmin .... so if the UPS cuts off maximum voltage between 12.8V and 14.6V then that is acceptable for Vmax. If the UPS cuts off Vmin at higher than 10Vmin, then that is also OK.

12V is only nominal rating for Lead Acid batteries, a full charged LA battery will be close to 14.2V, so the charging circuit in the UPS has to be able provide a bit above this to fully charge a LA battery. In older cars it was not uncommon to see over 15V at battery terminals when the battery was being charged by the alternator. Deep Cycle Lead Acid batteries as used in UPSs, I think, are very slightly different in terminal Voltage. Have another look through the comments, it is mentioned that the LiFePO battery will be only very slightly under charged, but this is good for any Lithium based cells as they tend to last longer if not charged to 100% all the time. Hope this clarifies the situation regarding Your concerns.