Replace BAD BMS on a Electric Bike Battery

[@Eric_Tennant]

😇Subscribe: kzbin.info I earn commission if any item is bought using the links below. That said I do give unbiased reviews of them given I had to use my own money to obtain them. 🛒BMS: amzn.to/3UXrvJT 🛒in line Meter: amzn.to/3nM6N28 🛒Multimeter: amzn.to/3PdFDgQ 🛒Solder Iron Kit: amzn.to/3W51BFl 🛒Solder: amzn.to/3g33HTf 🛒Heat Gun: amzn.to/3HvI7W3 🛒Solder Seal Wire Connectors: amzn.to/3hjfBwi 🛒Battery Heat shrink: [Listing sold out] 🛒Heat Resistant Tape: amzn.to/3FQv9RS

[@davidlittlefield2483]

Thanks for the sparks. That was pretty exciting. I thought, oh crap there's gonna be a fire. I learned a valuable lesson. Keep the heat gun away from the balance wires. LOL Great video Eric.

[@Eric_Tennant]

Think that thin red paper saved me from a house fire.

[@davidlittlefield2483]

@@Eric_Tennant Yes. You were super lucky. I have been tempted to change my bms or bypass the bms discharge wire to upgrade my controller for more a powerful one, but I will hold off until I gain more knowledge and confidence. My priority for next summer is to triple my range by adding 2 more battery packs. I'm thinking about building the battery packs myself. That will be a good winter project for me.

[@Eric_Tennant]

Just got a spot welder to fix an other battery. Now I have all the tools to build one. Still learning as I go, but other then making stupid mistake I know how to build one now.

[@1DumbSquirrel]

the darn video went to commercial right at the sparks flying moment lol i was like wtf happened thankfully nothing

[@illla]

They need to use XLPE insulation wires for those balancing leads

[@Eric_Tennant]

Agree they melted like butter.

[@hellskreamer]

Very nice! Thanks!

[@davidcampbell4218]

Forgive my ignorance. But how do you know where all the balance wire go?

[@BPRINC1]

As soon as I have a place of my own even if its an apartment I will tinker with batteries. I have always to do electronic class stuff like that but never had the opportunity.

[@Eric_Tennant]

Think I need to keep my fire extinguisher near by next time I do this.

[@SolarReturn1966]

Man, that was close! Id bet your wife would have had a real fit if you scorched her table!!! 😂 If that happened you could always tell her you got into a new hobby of wood burning😃😂🤣 But on a serious note, just a quick question and please forgive me for my ignorance but couldn't one place a fuse of some kind somewhere in the battery or the BMS? GREAT video my friend! If you use a fire extinguisher just make sure it's rated for electrical fires. Be careful and take care my friend!

[@Eric_Tennant]

Every balance wire would need one to stop what happen to me. Really was avoidable if I wouldn't of had the heat gun pointed at it.

[@dennisyoung4631]

Need to service *my* BMS, as it’s gone totally *dead* - no Volt’ums out at-all - and the battery proper is 90+ charged up. Got some sparken-spitzen getting the wrapping off. Am wondering about a 14S “smart” Daly BMS, with an active balancer. Comments?

[@Eric_Tennant]

This amzn.to/3Y33k1S ?

[@Eric_Tennant]

Here's what I did to all my batteries kzbin.info/www/bejne/qIm7ZXmEq75pns0

[@dennisyoung4631]

@@Eric_Tennant or similar, though *that* one doesn’t indicate what current capacity it has. I’ve *Heard* (read it in online forums) that one wishes to over-specify these things, e.g. if you’ve a stock BBS-HD good for 1500 watts in (30 amps or so…) you want a BMS that’s good for a fair bit more, e.g. 60 amps. Is this true?

[@Eric_Tennant]

30amp is all you need for 1500.

[@dennisyoung4631]

@@Eric_Tennant I’m afraid I’ll *smoke* it when I come to a bad hill if I don’t over-spec the thing. I’ll do some more looking so as to be certain.

[@1DumbSquirrel]

So what is you go to BMS

[@Eric_Tennant]

kzbin.info/www/bejne/qIm7ZXmEq75pns0 I add a external active balancer wire leads to all my batteries now with a Daly BMS.

[@dennisyoung4631]

Note: my BMS *never* charged fully, even from the first use. Oh, I have one of those 18650 eastshine chargers…

[@williamsouthwick6117]

The one thing that bothers me about your battery is that the cells are only isolated by the thin vinyl shrink wrap on each battery can! This is one of the reasons cheap Chinese short and catches fire.

[@Eric_Tennant]

True. In order to have the smallest foot print UnitPackPower likes that cheap 18650 heat shrink with no plastic inserts spacing them apart. This is common from most battery makers. Real danger is at the positive of each 18650. That paper ring really is the strongest part there as that plastic wrap rips easy, and positive negative only have that hair gap. Not sure what happens if negative to negative happens. I would think nothing, but I have not tested this. Hot glue and the 2 heat shrinks are the hope to keep the sides of each battery from ripping. Always have to be fast to eject the battery or be fast getting away. Really its not as common as the news would like you to think. I do like that Red paper. As it did act as a fire/heat stop for me on this heat gun fail.