Splicing/ connecting charge wires to battery

[DogDipstick]

there is also no way that controller will survive 80A for longer then a couple seconds.

I have a similar one that with which I could test that theory, Flippy. I almost built a hanging dead weight prony dyno yesterday for fun to figure the tq on a 24v motor I am using to charge off the steam engine in out current boat project.

 

[PRW]

I have ( a few of) the same controller but it is 96v, 55A, and the wires are much larger.... 10mm^2? Somewhere round there.. Just like the gauge of a QS205V3... SAme gauge as my Lyen 24FEt, or maybe a tiny bit less. Aside from that, looks identical to your 48v 70A. I have opened it and it has big shunts (4 I think) and decent spec transistors Fet banks. ( label).

Yours have a weird BLUE LED hanging off it? Mine do.

Interesting. Sounds like yours may be a better version. No, there is no blue LED.

 

[flippy]

I have a similar one that with which I could test that theory, Flippy. I almost built a hanging dead weight prony dyno yesterday for fun to figure the tq on a 24v motor I am using to charge off the steam engine in out current boat project.

put some amps on it. lets see how long those crappy chinese mosfets will live.

dont cheat with putting a fan on it. :wink:

might want to open it and see if something pops properly :lol:

 

[DogDipstick]

Pics

I sold one and it cam back, so I tried to get in touch with the company with no response.

 

[fatty]

thanks. I am looking for the Andersons locally, will look for the others as well.

I kinda doubt you'll find them locally (at least for a decent price). I get mine from Mouser.

 

[fatty]

How have these wires survived 5 years?

Also, I was intending to get a 24F Nucular when available, to have no stress on the controller. This uses 8AWG wire - but yet 300A battery max?

Because unlike connectors, wire doesn't fail until it fuses -- it just gets increasingly hot and lossy. Wire current rating is determined by safety factor of insulation temperature. Chinese controllers just have low or no safety factor.

Long before wire fusing current, the connectors will desolder. High-temp solder can extended current limit, or more accurately, cover up unsafe current limit.

 

[PRW]

How have these wires survived 5 years?

Also, I was intending to get a 24F Nucular when available, to have no stress on the controller. This uses 8AWG wire - but yet 300A battery max?

Because unlike connectors, wire doesn't fail until it fuses -- it just gets increasingly hot and lossy. Wire current rating is determined by safety factor of insulation temperature. Chinese controllers just have low or no safety factor.

Long before wire fusing current, the connectors will desolder. High-temp solder can extended current limit, or more accurately, cover up unsafe current limit.

thanks, starting to make a bit more sense to me now.

 

[PRW]

thanks. I am looking for the Andersons locally, will look for the others as well.

I kinda doubt you'll find them locally (at least for a decent price). I get mine from Mouser.

I can get the connectors below (or any more suitable on their website) with 1 day delivery. With items from the USA, I can wait up to 2 months, and the cost of shipping often exceeds the price of the item.

https://nz.rs-online.com/web/p/battery-connectors/6120071/

A potentially very stupid question: if I were to use bolted connections with ring lugs, I understand about bolting up say all the negative wires, and then isolating/ taping them off. How do you then work on the positive wires, without a giant spark/ being live?

 

[fatty]

I can get the connectors below (or any more suitable on their website) with 1 day delivery. With items from the USA, I can wait up to 2 months, and the cost of shipping often exceeds the price of the item.

https://nz.rs-online.com/web/p/battery-connectors/6120071/

Ah, gotcha -- I just meant locally at a brick-and-mortar store. rs-online.com is good.

A potentially very stupid question: if I were to use bolted connections with ring lugs, I understand about bolting up say all the negative wires, and then isolating/ taping them off. How do you then work on the positive wires, without a giant spark/ being live?

If you're referring to an accidental short, you might be used to chassis-grounded vehicles, where the risk of accidental short is obviously much higher. ebike frames are not (deliberately) grounded, so the risk of accidental short is lower.
You'll still get a spark when first connecting the controller due to the capacitors charging, unless you use an anti-spark connector.

 

[PRW]

Thanks fatty for all the help - much appreciated

 

[PRW]

so, I changed all connections to Anderson SB75's. New issue - the battery voltage seems to have dropped so low in the meantime, it won't charge/ Satiator has trouble trickle charging.

I have stored it in an ammunition container for now, well away from any other items.

[youtube]YpEAjpdQ8Zo[/youtube]

 

[fatty]

Looks like it initiated around 15-17V, so under 1V per cell in a month?
What is the actual resting voltage of the pack right now?

Who is the maker/seller?

 

[PRW]

Looks like it initiated around 15-17V, so under 1V per cell in a month?
What is the actual resting voltage of the pack right now?

Who is the maker/seller?

resting voltage is 14.7v.

I have emailed the maker (local guy in NZ), am waiting to hear from him

 

[fatty]

The pack doesn't have a BMS, does it?

Was it left connected to the controller (or any other load) during this time?

 

[PRW]

The pack doesn't have a BMS, does it?

Was it left connected to the controller (or any other load) during this time?

it does have a BMS. It wasn't connected to anything during this time.

Just measured the voltage again - now it is 24.7v. Something very weird going on.

 

[fatty]

Then either the cells were bad when the pack was built, or the BMS over-discharged the pack (which is why we refer to them as Battery Murdering Systems..).

Either way, if the cells have been pulled to <1V, then the cells and pack are damaged and should be replaced.

 

[PRW]

so... an update on this - and then a question.

I sent the battery back to the original builder, as I couldn't see what the low voltage problem was . One pack was gone (didn’t had any voltage left and he was not able to bring it back). Two other packs didn’t keep their voltage. So 15 cells to remove. With breaking up the pack, he created a major short circuit - big spark, then a fire. Luckily he managed to get it out the garage - but the whole pack was destroyed.

So, a new battery build by him!

The question: how do I do a bolted connection (2 10awg wires with both connectors to the controller wire) without creating a spark? I wired up the black and insulated the connection, when I touched a red battery wire to the red controller wire there was a big spark.

 

[PRW]

in answer to the question above:
would this work https://lunacycle.com/as150u-anti-spark-with-signal-wire-connector-set-with-pigtails-male-and-female/ ?

Could I use it for the red wires only, leave the black as bolted connection?

thanks

 

[999zip999]

You can leave the black wire hooked up but you need a 100 watt 10amp resistor on a red wire to pre connect before the main red wire. I use 5.5mm gold bullets for mains. Going downstairs in about 10-15 minutes in check what size resistor I've been using.
Batteries can be tricky especially at 22s a lot of stored energy and flipping around and taking apart and trying to put them back together. It's easier just to put them together the first time then to take him apart and rebuild them and put them back together that's the dangerous part.

 

[PRW]

You can leave the black wire hooked up but you need a 100 watt 10amp resistor on a red wire to pre connect before the main red wire. I use 5.5mm gold bullets for mains. Going downstairs in about 10-15 minutes in check what size resistor I've been using.

great, thanks vey much

 

[999zip999]

I forgot I'm down at the beach now I think it's a hundred ohm 10-watt I have to check it out I have the paperwork done in a drawer and I have to find it I'm going out with my maiden voyage of my Samsung 20s 6p triangular battery muxus 3,000

 

[PRW]

thanks - please also take pictures. have fun!

 

[999zip999]

The top photo has their pre-charge resistor with two 4mm gold plated ends the other is 5.5 mm maybe 8 gauge main wire and above it is the negative 5.5mm gold plated wire plugged in. that's for a 72 volt 8 ah 20s battery a spiam08 8ah cells for 100 00 plus parts

 

[PRW]

Thanks for all the help, 999zip999, that's very useful

 

[999zip999]

I also have have for a few months a Samsung 20 s 6 p 40 t 21700 cells in a triangular pack. For a mid drive that I can't get the Bluetooth controller synced up so I put the battery in a different bike Lyen controller 18fet and mxus 3,000 4t. Just so I can get a few cycles on it and not let it sit in the corner. I measured a em3ev bag and have them custom make the battery but since these cells are taller then 18650 I had to go to the shoemaker and pay 80 bucks to have them fix it twice. Live and learn. The first time it wouldn't fully charged I sent it back he put a few more cells and for some reason ?And a Bluetooth bms that I've never been able to fully operate to see each individual cell voltage. Maybe fake cells ? Just trying to see how close I can get to 24 ah out of it ?
PWR I hope I just didn't run over your thread. Of course I did. Lol.