48V Battery Pack Issue (How to Check and Fix it)

[@johnbrevard5966]

7:40 Love the welder... Total admiration for doing it.

[@EVCustoms]

hello John.. this spot welder working until now 6 years..

[@davidv6501]

Did you check the individual cells in the group? were they all heaters, CID's, bad?

[@alibro7512]

How come the pos end of the batteries wasn't spot welded? Excellent video BTW, thanks for sharing and I like your DIY spot welder, I have put up some videos of mine but it still needs some refining.

[@ecarcompanyinc5129]

Why did you replace all the cells on that series? All of them were bad??? Or ?

[@seppl733]

Good point! Further explanations would have been helpful..

[@forevercomputing]

Most likely a bad cell bringing the others down so degrading them faster also.

[@ismaelbanuelos9572]

I have a 36v 10s battery its takes a day to charge and drains extremely fast, if I stoped using it the charge starts coming back up the dies faster when I use it again. Do you have any advice on what the problem might be.

[@forevercomputing]

A cell or cells have failed. It's charging slightly faster than the drain rate. Charge should hold. Every battery has self discharge

[@BERMUDA1149]

Like this. My issue is the battery pack is fully charged. As I road off the bike suddenly looses power and shuts down. I have 2 Battery packs and this only happens with this on. Any ideas. Thank you

[@forevercomputing]

BMS shutting down as power output too high, or cells not rated for such a high output. Getting a motor to start requires the most power.

[@poypoy9028]

Does the the one you repair same c rating?

[@forevercomputing]

The replacement battery should at least have the same voltage and charging voltage as the others, you can exceed the rating safely, but don't go under.

[@ogordodesagres]

Hello, can you do a video on how to balance a 21s pack?

[@LetArtsLive]

I screwed up my bike battery by leaving it plugged into long. Because I bought a crappy charger that's not UL listed FC or whatever it is. If you lived near me I'd pay you $100 and by the freaking batteries although that looks pretty easy I don't have a spot welder I don't have the tools you have. How did you figure out which battery by the BMS? Why was it saying 40 volts?

[@petvdv9671]

you give me new hope! I have issue with 52volt 14s battery 20ah it is the 2nd BMS that I try I have measured everything, I have 56volt can make a 220v lamp go but the motor will not run. also cannot load

[@ravikeerthi8052]

Hello, Thank You for detailed video. I have a 48V custom Lithium Battery pack, newly built. Battery voltage reads 49V, but when i try to charge, charger show as full charge. When i check each P i see that P1 - P2 is OV and all other Ps are fine. Does this mean i have to replace P1? I do not know problem is with charger or BMS? Please educate me. Thank You.

[@EVCustoms]

Yes it is possible BMS is defective but it is possible also one battery of itch P1-P2 can be defective and discharge your batteries.

[@ravikeerthi8052]

During charge wire soldering, there was short circuit once. Do you think this could be reason for one or more battery to go bad? But bms comes with short circuit protection.

[@EVCustoms]

Yes but BMS board have short circuit protection on output, shortcut between batteries cannot protected from BMS.

[@ravikeerthi8052]

Okay. Now possibly either one or more cell or BMS or both, could be bad. Am i correct?

[@EVCustoms]

@@ravikeerthi8052 yes

[@ismailgul9066]

not good man how do you know that replaced cell has same capacity as other cells ?

[@deejaybigzz]

Misleading video replacing Panasonic cells with Samsung

[@rachidbaaira9869]

Hi, plz I have a question : can I run a Xiaomi (250 watt) with 36v hoverboard battery?? ( I make path just a 2km in day) , plz someone answer me. tnx

[@thinkingmindzzz2212]

Bro I have made 34ah 48v battery pack I have used quality BMS but total power not delivering at full charge it giving 2 km range hardly can you please help me? The motor rating is that 48v 1000w Yalu company motor

[@forevercomputing]

What cells did you use?

[@alexmoro348]

thanks for sharing !!

[@Haiduk1985]

You replaced panasonic 2250mah (10A, 17A peak) cells with samsung 2600mah (5.2A, 10A Peak) cells? WOW, - is it safe?

[@hexidev]

No

[@forevercomputing]

@@hexidev This answer

[@themystx2]

excellent video! Beyond my skill level though. Do you know if anybody in the US could repair a bad battery pack? It’s brand new, but I surmise there is a bad set of cells in there (crazy voltage sag, BMS cuts within 7-8km) 60V 33.8ah battery.

[@EVCustoms]

Sorry friend i don't know anyone in US.. I live in Ciprus :)

[@joblessalex]

If it's acting like that, it probably isn't worth fixing, but I can check it out to make sure it's fully built right. Most likely the cells are garbage and it would be a full rebuild with new cells. Always a possibility it's just a couple disconnected cells causing a sag tho.

[@md.saifulisl894]

youc are great broo

[@bob-ny6kn]

The most important part, balancing. Fin.

[@chrispayne1573]

By king of Battery Balancing meter is used I have thirty trikes with 5 bad batteries to rebuild, it help would be appreciated.

[@sumeeths8423]

How did you know that there was a problem?

[@EVCustoms]

If you look carefully when i measure voltage for eatch single cell, you well see that one pare of 5 parallel cells give 41Volt instead 3 - 4.2Volt.

[@seppl733]

@@EVCustoms 41 Volts? How can that be? Shouldn't bad cells mean a voltage lower than the others? i.e. 3.4V?

[@andosoup98]

@@seppl733 thats what i was wondering but maybe they can fault to a higher volatge somewhow

[@EVCustoms]

if you have some conception from BMS (LOAD) you can read high voltage from other batteries, like main battery voltage because the bad batteries didn't have any resistance - continue there..

[@Drivers-TV]

i feel like its a how not to spot weld video.

[@haiduks1985]

This video should be banned for peoples safety.

[@linusleblanc6348]

Wish you talked

[@scottbates100]

Doesn't explain how you found the individual dead cell, terrible instructional

[@sameerjunaid1]

With finger 🩹 bandaged up and making a video that’s dedication I field stay away from garage for weeks and still go back to work without gloves hahaha ! Is it just for video or customers ?