Removing swollen batteries from, and servicing a 1500 VA APC UPS

[@tonyeezi7315]

I had this model but I wired in an external Anderson style connector which went to a pair of AGM leisure batteries as they could take the high float voltage better than flooded batteries could. I did this when I saw the price of genuine replacement APC batteries. I now use a low frequency 3KW inverter with UPS capability, which has worked flawlessly for the past 3 years.

[@bannor99]

You can tell how old an APC unit is from the serial #. The 1st two digits after the initial letters is the year of manufacture and the next 2 are the week of that year. So a serial like WS9915112233 indicates a unit made in the 15th week or late April of 1999. I believe this applies to all their devices such as the AP8853 PDUs, or the AP96xx network mgmt cards and the UPS batteries, too.

[@yummynikko28]

Hi to all, for battery constants I would suggest to call our world wide support. The code above is not the default for this model it should be A1. Each of the codes are specific per model and putting the wrong code might damaged the unit due to miscalculated estimated.

[@itsmesb4399]

My smart ups 750 (the old one) from 2003 has 6 year old batteries which are in perfect working condition. Ive never touched them appart form checking them every now and then.

[@Вася-ш3щ]

How are your batteries now? If I were you, I would open them up and add a little distilled water to thoroughly saturate the fiberglass separators.

[@timlipinski2571]

My APC Smart-UPS 1500 has been protecting the desktop computer for a couple of years. And the idiot lights are all green and show a full charge. Thank you for the video ! tjl

[@dash8brj]

Just to note I just did my SUA3000RMI2U with a 6800uf 160Vdc capacitor and set it to 54.4 volts, - the cap didnt have enough oomph to sustain the self test (battery) but it worked for adjusting the battery voltage on the charger. I charged it with the 4 defunct puny batteries from the ups. It made quite a spark - I should have used a resistor in series. Probably not healthy for the cap :)

[@philindeblance]

Great video!! I thought that when in parallel they should still be reading 12v. I just did the replacements, and even upgraded a 1000 to a 1500. You didn't mention the fuse spec, but I guess it maybe series and 24v? since it is 32v 100amp fuse..maybe for spikes when turning it on. Btw, I changes my batteries to 22AH vs the standard 18AH. BTW, the swelling you had on the cells was very little compared to the ones I pulled/forced out.

[@electronicsluckydip]

Hi. I have a trash picked white "APC SMART-UPS 1400I NET" which I have recently got into service thanks to your videos (It looks just like the model in this video but it's white and has serial only, no USB). I can communicate with it via apcupsd. Do you know if I should be looking at the capacitor method or the voltage divider method to tweak my charging voltage? You're an inspiration - thanks and happy new year!

[@techRoom429]

Thanks for sharing all of this information... am I right to assume that this information applies to (which is a very similar) APC Smart-UPS 1400? This was a unit that had tripped the failed battery light and I replaced with a more modern unit... When I powered it down, I suspected it would turn back on without issue... However, this was not the case, and I'm glad I swapped it before it finally quit, as our entire VOIP system relied on it! Long story short, the unit's batteries were seized up like this, and it would no longer power on. Now I just need to decide what to do with it, correct replacements, or maybe car batteries like you've did on your other.

[@FFcossag]

+Jake Johnston If it's a white unit, everything applies, except that you can't set the battery voltage using software.

[@LasVegasVocalist]

This is exactly why you NEED to replace your batteries every 3 years. 4 is pushing it and 5 is the absolute max. After 5 Years, this video is the result.

[@charv3x]

Could you tell us how to connect the capacitor and the power supply (which in 9:06 - 9:22, it the power supply seems to be ON, but we don't see where the red wire goes to, only the black clamp were shown and the capacitor connected to the charging connectors) to jumpstart the UPS so we could place the multimeter while adjusting the parameters? I took an UPS (APC with different model, SC620, single battery) with discharging battery problem, I think it's the parameter needs to be adjusted after changing battery. I intend to repair it for personal use. Thanks

[@FFcossag]

It's hooked up in place of the battery.

[@charv3x]

oh, I see... then I'll try that. thank you

[@jerryquigg3497]

Excellent instructional. What's the first SW screen with the (12) options to pick?

[@FFcossag]

jerry quigg That's apcupsd's apctest utility.

[@donovanpl]

Is there a way to specify the shutdown battery voltage of the inverter? I am not interested in how much more time I have. I am more interested in protecting the battery; i.e., depth of discharge to extend the life of the battery.

[@FFcossag]

The battery voltage readout value (B) can be changed. THis changes the charging voltage and cut-off voltage.

[@donovanpl]

FFcossag thanks for the reply.

[@donovanpl]

What does the battery bar graph show; is it a representation of the level of the battery voltage, or remaining runtime?

[@donovanpl]

FYI, I conducted some experiments: 1- Connected a power supply to the battery terminals on the ups without the batteries. Powered up the inverter (inverter off) with the line AC on. The power supply has a diode in series with its output in order not to damage the power supply. The battery LEDs did not vary with the voltage from the power supply, which was surprising. I then set the voltage to 27.5V and left it running for about an hour and the LED's slowly climbed up. 2+ hours all the LEDs lit up. Seemingly, the UPS thinks it has charged the batteries. The LEDs seem to indicate the amount of charge in the battery probably based on the length of time it thinks it was charging the batteries. The power supply was left unchanged from the 27.5V. Strange enough, before all of this, I was experimenting to determine how low the UPS would go before cutting out. So I had the power supply and the battery connected, started up the inverter with no line power. Then I removed the batteries, while the power supply was still connected. I lowered the power supply voltage until it was V1 (gosh, I cannot remember what it was), when the beeper started to sound, started timing it to see when it would go down, went over 10 mins. 30 seconds, at which point I continued to lower the voltage to V2 (I should have written it down), when the UPS went off. During the decrease of voltage from the power supply, the LEDs went down to 1 bar. Subsequently, when I increased the voltage back to 27.5V, or higher, then LED's remained at one bar. After all of this, I'm not even sure what to conclude. Comments?

[@donovanpl]

Further testing: Started up inverter on power supply (constant voltage) and no line power; all LED's lit. After about 3 hours the bars are down to 2. So it seems the LED's are controlled by time (possibly power consumption) and battery voltage on discharge. I assume battery voltage takes precedence over time.

[@johnny50424]

i had a similar ups and the ribbon cable came lose and fired a chip on the main board. those are nice ups. i just hate that you can not disconnect the ribbon cable to get the door out of the way when changing the batteries.

[@philindeblance]

+robertelee2k9 truth seeker You can easily take off the ribbon with the small switch board from the front door. There are 2 clips and it pops right out. Easier to handle and less chance to damage it.

[@johnny50424]

UnknownHandle UnknownHandle too late now. i threw it away years ago. i just do not like that design. they could have made it where you could just unplug the cable from the board.

[@philindeblance]

+robertelee2k9 truth seeker I still run 3 of them. I recenetly purchased a ...(let me see here) CyberPower 1500PFCLCD. Much lighter, slimmer, smaller unit. Not sure if it uses any Lithium power in it, but maybe they are lead acid that are newer more efficient design. Somehow I doubt they will do the same runtime as the APC 1500's I have. We'll see how easy or hard it is to replace the CyberPower cells once they hit tilt.

[@johnny50424]

UnknownHandle UnknownHandle i put two 18 amp hours batteries on an apc back-up 1500va i bought to replace the one i damaged. i hacked it to have external batteries that would last longer between having to replace batteries. the batteries that came with it did not last a year before they degraded. they put to small of batteries in these ups they sell at office max.

[@philindeblance]

+robertelee2k9 truth seeker ..Nice to have the room for external batts, but I have limited space under my desk, and rather have it "portable"(50# isn't really portable:-) than pieced.This is my second replacement. First ones were over 3 years ago. I have 3 and only 2 needed the replacement. The 3rd APC is going on 4th year. I purchased Universal Brand batteries, and they were 15.5volts when they arrived. I'd like the Putty sw to adjust the volts, so I may need to see how to run that app on Win7x64bit.

[@db-jw6ig]

Very good video! Would like to know more about connecting to the APC UPS serial input. Is there a way to do that with a unit that comes with a USB cable (Back_UPS XS 1500)? When I remove the Powerchute software, plug in the cable and look for ports to connect with, Putty can't find it's USB input.

[@goagola]

Hi, any reason why a unit with fresh batteries would not stay powered on? it makes a loud chirp/beep, flashes LEDs and shuts down immediately.

[@ZARuslan]

Thanks for video! Can you please "write" necessary buttons to push with description, like 1) Y. That will send UPS to PROG mode. I can't "hear" correct what to press :) English is not my native language. Thanks!

[@FFcossag]

+Ruslan Zamaletdinow The APC smart protocol is pretty well documented, check this out: www.jusch.ch/dokus/apcupsd/upsbible.html

[@ZARuslan]

+FFcossag Thanks for tip!

[@droneeyes5989]

Link not working

[@GaryBeltz]

What typically causes batteries of any kind to swell? I mean SLA, Li-ion, etc

[@FFcossag]

In a nutshell, overcharging.

[@best3140]

i have 1400 model. it have no led lit or any sond when plug it and press test button. how can i check it can use or not ?

[@FFcossag]

You need to supply at least 24 V across the battery connectors. The easiest way to do this is to install a known good battery.

[@ErickMoraes16]

Good afternoon FFcossag I speak from Brazil and here my SUA3000-BR is charging with 24V and the batteries did not charge although the display indicates maximum charge and for the hyperterminal the constant and battery fluctuation are ok, but when I tested with the equipment 12V SLA Battery Capacity Analyzer and the capacity of the CSB batteries were at 38% and when installed capacity was 76% and the UPS was charging 48 hours. I think the charger has to stay at 27V for a full battery recharge.

[@javieratam59dotnet]

Have you tested these units with any 27 or 29 volt deep cycle marine / RV batteries? I just became aware these existed.

[@FFcossag]

Works fine with all lead-acids, really. Just adjust the charging voltage accordingly.

[@javieratam59dotnet]

Just saw your reply now. I am attempting tonight to adjust a UPS for 2.15 volt / cell. I am using SLA now but I will be moving towards LiFePo4 and Li Ion batteries in the long term.

[@DanielCoffey67]

Do the newer APC SmartUPS models still suffer from high float voltage? I have a SMT1500I from 2017 that is showing signs of a battery problem and I am wondering if they still have this issue.

[@BryGT500]

Great video, I have a PFpower M1500-ups-pfp rack mount unit, that works but will not maintain the batteries voltage, I'M unable to locate a circuit schematic to help troubleshoot this issue. Any suggestions would be greatly appreciated. Thanks

[@yusifsuleiman5502]

Hi. Please, kindly assist. I have such of 1500 ups, which works fine with two external batteries of 190ah 12volts connected in serial. I use solar panels to charge the batteries. The Ups later start to select batteries (works with some batteries and not to work on some other batteries). Now it refused to get on. What would you recommend for fixing it.

[@FFcossag]

Test your batteries first. Then replace the capacitors if your batteries are known good.

[@yusifsuleiman5502]

@@FFcossag the batteries are working with other ups/inverter. At last, I suspect or the start/on button has problem, however I open the unit, I try to bridge the line with a conductor, but it make sound like it will start, unfortunately it won't. Please, let me have a link if you have video on changing the capacitors. Thanks again for your assistance.

[@paulchu9961]

Hi FFcossag, (1) Where can I get this "COM1 PuTTY" software? (2) Does the "COM1 PuTTY" work on RS800? (3) What's the advantage of installing the huge low-voltage capacitor instead of a lead-acid battery? (4) What's the formal name of this huge low-voltage capacitor? I could only find the small electrolytic caps (thumb size) in online shops and couldn't get this 35V 45000uF. Is it a "supercapacitor"? Thanks.

[@FFcossag]

The software is just called PuTTY, it's a terminal emulator (usually the first hit on Google). I don't think it would work with your RS800, since I believe those are USB-only, and PuTTY can only talk to UPSes over serial cable. I hook up the big cap only in order to calibrate the battery charging voltage on black Smart-UPS units. It's just a question of convenience, since the UPS won't charge properly without a battery connected, and a lead-acid battery will take minutes to adjust to the new charging voltage. A capacitor takes less than a second, so setting the voltage goes a lot faster. It's pretty pointless to get one for an RS800, if that's what you're asking, since those don't have software adjustable chargers. ;) The capacitor is a simple aluminium electrolytic capacitor, and there are plenty of its size available from, for instance, Mouser or Digikey.

[@zetasyanthis]

Okay, real question this time. Is the battery output isolated from mains power? Asking because I want to be careful when I try this.

[@FFcossag]

On these 3rd gen APC Smart-UPS devices, yes it is.

[@zetasyanthis]

Question on this... You said that you usually set to 13.5V when you're reselling units. Is that what you recommend for home use? (Recently snagged one of these off Ebay and want to make sure I don't nuke my brand new batteries.)

[@zetasyanthis]

Oh, doh. I missed that section. (Sorry, had been re-watching and I didn't think you'd covered it last time I'd looked.) Sorry, and nevermind!

[@FFcossag]

You should set the charging voltage according to the datasheet for your batteries if you're using quality batteries. For generic cheap-o batteries, I tend to stick to 13,6-13,7 V per 12 V block. Higher voltages will usually cause relatively quick failure.

[@philindeblance]

After I did the swap and added the 32volt/100amp fuse, I had put them back to work. But I had them plugged into a curuit that I use in a socket outside. I used a pressure washer on it that draws a high amp power, maybe 13+amos? But it caused one of the APC 1500 to smoke and spark and made the house smell of electrical burns. At first I wasn't sure whaty the source was..only after sniffing around, this unit was it, and I pulled the batteries out, and see black smoke on the quick connect /grey connectors, and undid that. Any idea what might have fried? or why it did this?

[@FFcossag]

+UnknownHandle UnknownHandle It's difficult to say. I hope you didn't connect the UPS output to your house wiring - they are not built to do that.

[@philindeblance]

of course I plugged it into the house outlet. As designed, and as I have done for over a decade...(?)

[@dj03djj57]

Hi, I just acquired a Black 1500va APC UPS the same as the one in your video. This also had swollen batteries which I have replaced. Now when I turn the unit on it does a self test and fails showing the overload LED even though there is nothing connected. The green LED on the rear panel is also illuminated and constant alarm sound. Any ideas what could be causing this.

[@FFcossag]

DJ03DJJ I've never seen this before, but it could be an internal failure of the unit. If it makes a loud humming noise during the self test, the output is likely short-circuited. If it doesn't hum, something is wrong with the switching circuitry, if it hums normally, something's likely wrong in the feedback loop.

[@yusifsuleiman5502]

It seem I have similar problem, I wish to have gotten a solution to this problem

[@ictrepairs6963]

May be not the best place for asking... I manage to repair a back ups es 700 series with a blowed mosfet after replacing the leaking caps... Now it works but when on batteries i get 99,9Hz on main output in stead of 50Hz !!! The voltage itself is right and stable. What do you think will the problem arise to?

[@FFcossag]

+Luigi Mazzoli Double check the frequency with a scope. If you're using a multimeter to measure it, it's likely just triggering wrong due to the chopped up output.

[@ictrepairs6963]

+FFcossag I'll do it with the scope just to be sure. Today I have just measured with my dmm ( BM869s) another identical unit and I got the right Hz value on battery operating mode... I just replaced most of the caps and one of the two mosfet with an equivalent one ( 100A in stead on 80A) before experiencing the issue. No idea of what could make such a big (double) increase of the output frequency? Thanks for your time, I really appreciate it.

[@FFcossag]

Luigi Mazzoli It's because the high-frequency harmonics on the almost square wave coming out of the unit causes the DMM to trigger twice per cycle.

[@ictrepairs6963]

+FFcossag Isee.. Assuming that, I still wonder why on the other identical unit, the same problem didn't shows up...

[@FFcossag]

Luigi Mazzoli It depends on a lot of factors. The battery voltage impacts the peak voltage, the peak voltage impacts the duty cycle, and all of the above impact how the DMM counts the frequency.

[@GeertDroid]

Do you need a special custom RS232 cable to connect putty console?

[@FFcossag]

Yes.

[@GeertDroid]

Can you give us a link to such (diy) cable?

[@FFcossag]

Geert Pirens Google "APC smart cable".

[@turgsh01]

That's nothing... barely swollen at all. My APC 2200VA had 2 pairs of those batteries in it and they all swollen up to 1/3 bigger in all directions overnight due to charging issues. A few ppl told me it should have busted and were surprised it didn't... maybe the heat helped stretch the plastic. I think the batteries still work just fine though, but they aren't going back in the UPS, I'll use them to run lights in the shed or something. I unplugged it so I could open it up and blast the dust out and clean the fan as I thought it was the thing that was making an annoying sound, all went well, fully cleaned that fan and lubricated it, blasted it with air to flush out the excess oil, plugged it back in and it showed the batteries were dead when they weren't, so I unplugged it and ran the computers off of it until the batteries were actually close to being dead which took about an hour (gave me a different beep to let me know it's close), plugged it back in, charged it back up just fine. Unfortunately, it seems like it wouldn't stop charging because the next night, the batteries had reached 85 degrees celcius and bulged out like crazy. I of course unplugged it and retired it for now until I can figure out a way to maybe / hopefully fix it and buy new batteries for it again. I believe it was made in 2004, replaced the batteries once, 2 years ago. I am a certified computer troubleshooter with many years experience, but UPS's are a little different, so I don't really know what needs fixing. That sound in which I thought was the fan, turns out to still be there even after all that effort in cleaning / lubricating, so I don't think it's the fan anymore. I've always gotten an annoying buzzing sound in my speakers whenever the UPS went into battery mode (I assume it's because of the transformers or something), but thought I would mention it anyways just in case. Aside from that, I have no other info for it atm. The display never showed any errors or signs of problems at any point in time, which of course is frustrating cuz it should have stopped itself before cooking the batteries like it did. So far, no one wants to attempt to fix it for me which sucks cuz it's a $1500 unit and I'd be willing to spend quite a bit of money to have it fixed, or at least if I could gain some info for me to fix it myself.

[@inachu]

turgsh01 Hope you had air circulation because in a small room that would be a fire hazard.

[@turgsh01]

Inachu Ikimasho It was in a small room (tiny apartment) with not much air circulation... but there was no fumes or w/e leaking out... the batteries held together... somehow.

[@inachu]

turgsh01 To prevent future fires only rest those types of UPC on a brick or non flamable surface. I do the same with the power bricks for the XBOX 360

[@fumezflori]

Hello, thank you for this video. I want to ask you if this kind of UPS is suitable for a lithium battery pack made from 18650 cells. I have one APC 1000 with similar box, also I have 18650 cells from old battery laptops that I can use, problem is that they have a special requerments for charging and discharging them, could the UPS be set to stop send charging the battery at 25V? ( 6 cells series fully ch 25 V).

[@FFcossag]

+fumezflori You'd need some kind of protection and charging board, and the UPS battery meter would be incorrect. The charger on a lead-acid UPS is ABSOLUTELY NOT suitable for charging lithium cells.

[@fumezflori]

+FFcossag Ok, thanks. Onther ideea that I have in mind is to use the inverter part from the UPS to change dc 24V to 220 AC (EU stand), as part of a solar setup. This could be done with minimum intervention? Thanks for your quick reply.

[@FFcossag]

fumezflori Yes, but you need to derate it about 50 % or add a second transformer, fatten up the low voltage traces, and massively improve the cooling of the transistors. That said, I've done just that, and it works fine. But it's hardly "minimum intervention". They are also not very efficient - below 80 %.

[@benjaminmartin4158]

Hi, could you explain APC's model numbers. I am looking to buy a smart ups, but I want it with pure sine wave output. Thanks

[@FFcossag]

You have to check their website, their newer series are a bit mixed-and-matched. Generally, all the "black block" 1000VA+ Smart-UPS models are pure sine.

[@yamero3192]

Hey, can you show how to open the case of this SUA UPS? I think my UPS fan a little wobble it make vibration. Thanks

[@FFcossag]

Undo the bottom screws, and lift it straight up. You need to bend it to pass over everything.

[@yamero3192]

FFcossag Ahhh I see. Thanks man 🤝

[@puddnjones9816]

I accidently severed the ribbon at the faceplate. Do you know of anyway to reattach it??

[@FFcossag]

+Derrick Forshee It should just be soldered.

[@davids8841]

I did the "B" command and it returned 55.08. I am in the US and have a SUA2200XL with 2 battery packs. Is this correct? I just replaced the batteries and most of them were swollen. WHat should my voltage be?

[@FFcossag]

David S The B command will always return about that when the batteries are fully charged. Divide by four and you get the voltage per 12 V battery. You can NOT go by this value when adjusting the charge voltage, you need to use a multimeter.

[@newvaper3794]

i am using an APC SU700INET. it is an old UPS. I bought two new batteries and hooked it up. charge the battery to full charge but when i connect my laptop the batteries completely drains in 5 minutes and these are new batteries. what is wrong with my UPS. please help me. i already lost the serial cable.

[@FFcossag]

You need to reset the battery variable using the terminal. Your new batteries could also be bad.

[@newvaper3794]

@@FFcossag the batteries are brand new. just purchased these batteries 2 days ago.thanks for the reply. i just purchased the cable and waiting for it to arrive.

[@FFcossag]

It's very common for these small lead-acid batteries to be dead on arrival. Sometimes the infant mortality rate can be as high as 10 % - that means, one in every 10 batteries delivered to the customer are bad. Just because they're new doesn't mean they're good - they need to be tested.

[@armankordi]

My old 1400 tends to charge one battery at 14.7v, and the other at 12.6. What's going on here?

[@FFcossag]

Your batteries are unevenly charged and probably fucked.

[@10mbc]

What software are you using at 10:16?

[@FFcossag]

the apctest utility included with apcupsd

[@10mbc]

Thank you for that quick answer. I do have another question: just bought 2 UPS for use at home, a SUA1500i and a SMX750I. The SUA1500i is silent most of the times (except the normal transformer hum while running on batteries). The SMX750I is plain noisy. It has some kind of hiss noise and it is pretty annoying. Is there an issue with my unit? Is this a design flaw? I would assume you would hear nothing in a rack near some servers but in my quiet room it's annoying.

[@FFcossag]

I'm not sure, I've not had opportunity to play with the newer units.

[@krzysztofsoja5301]

Hmm I've tried to reconfigure A/D C in Smart-UPS 700I unit but it didn't change charging voltage at all (even with capacitors connected). Any ideas how to adjust that voltage in this type of unit? Help please :)

[@FFcossag]

If it's a white one, you need to find the battery voltage divider resistors and change them.

[@krzysztofsoja5301]

FFcossag many thanks. I followed your advice. The solution is to add 5.6 megaohm resistor in parallel with R118 (~72kohm). Job done!

[@FFcossag]

Yep, that sounds familiar. I've done it at some point, long ago, and it worked well.

[@yuriramos1308]

Did you use a rs232 to usb adapter or you laptop actually has a rs232 port?

[@FFcossag]

That laptop has a serial port built into the docking station. It's not the most modern machine, dating back from 2006.

[@ronaldhk1142]

same problem, SWOLLEN!!!!! is it possible explosion?

[@FFcossag]

+Ronald Hk There is no major risk of explosion. The hydrogen gas doesn't have enough time to gather a high enough concentration inside the case.

[@meatdogg101]

do you have the original computer software for the unit?

[@FFcossag]

I haven't used that in a decade.

[@OffGridAussiePrepper]

Have u ever thought of converting the UPS to a lithium cell using the 18650 batteries??? The problem I would have is figuring out a charger for them, but fer u I think it wud not be a drama at all.

[@FFcossag]

+OffGrid Aussie Prepper™ All you need is a CC/CV charger that does a 24 V string of Li-ions. Probably not that hard to source, but it's difficult to justify a lithium UPS since you don't need it to be light or mobile; it's easier to just use bigger lead-acids that cost 1/5 of the lithium equivalent.

[@OffGridAussiePrepper]

I recycle laptop batts so theres no cost for them. I have asked a few pc shops to save them for me and collect them once a month or once every 6 months. Then take out the dead batts and build a new battery bank with em. I have no idea what a CC/CV charger is, I need more info pls.

[@FFcossag]

OffGrid Aussie Prepper™ Combining random used lithium cells in higher voltage strings is generally not a very good idea at all. Especially not in a high-current application like a UPS. I'm not really the right guy to ask about this, since I've never done a lithium ion UPS conversion. I don't know which particular charger you want or what other unexpected hurdles might pop up. I can just tell you the basics so that you can do your own research based on that. Back-of-the-envelope, though, using li-ion cells for a 24 V UPS is going to be tricky, since they don't really give you the correct voltage range unless you use 7 in series, and finding a 7-cell protection circuit/charger/etc. is going to be next to impossible unless you design it yourself.

[@davidbolha]

@ 10:42 Your laptop looks awfully like an HP Compaq nx6325... am I close ? 🤔😉

[@kiskiller3]

at 9:00 yes the board is hot and once after a load test with my 1kva unit i wnet felly felly around to see if it was hot and i forgot to disconnect it... yes i know its hot lol dumb me !