Search found 160 matches

by hemo
Oct 04 2019 3:41pm
Forum: Battery Technology
Topic: low batter voltage cutoff.
Replies: 26
Views: 521

Re: low batter voltage cutoff.

Just my penneth worth, don't froget this is 14s not 13s.
39.2v is too low and is 2.8v per cell group, 48.1v is more sensible and 3.43v per cell group. The bms or controller cuts out when lvc is hit and at 48v or so is likely down to voltage sag.
by hemo
Jul 25 2019 1:49pm
Forum: Battery Technology
Topic: Which Nickel strip size do you use for your 18650 packs?
Replies: 4
Views: 344

Re: Which Nickel strip size do you use for your 18650 packs?

Will depend on the discharge amperage one is needing and whether cell spacers are used.

Me personally I now use H strip for cell holders, though also do have 8mm X 1.5mm pure Ni as well as 0.15mm sheet.
by hemo
Jul 07 2019 5:55am
Forum: E-Bike Non-hub Motor Drives
Topic: Gospade Mid Motor
Replies: 2
Views: 1124

Re: Gospade Mid Motor

Gospade is Cadence pas drive and about 2.6kg.
Here in UK Woosh bikes have said they have a 100nm custom option on order for Autumn delivery, unsure whether it is 36 or 48v though will be marked 250w to compy with UK/EU law.
by hemo
Jul 01 2019 12:03pm
Forum: Battery Technology
Topic: things not to forget before heatshrinking my self made battery
Replies: 8
Views: 431

Re: things not to forget before heatshrinking my self made battery

I haven't come across one yet.
Loads of cheap voltage displays that can be wired in.

Double/triple check all voltage readings before shrinking.
by hemo
Jul 01 2019 11:30am
Forum: Battery Technology
Topic: how to know it ithere is a faulty cell or paralele groupe in my diy pack
Replies: 2
Views: 182

Re: how to know it ithere is a faulty cell or paralele groupe in my diy pack

1. Cells paralleled with differing voltage will balance out though during this balancing out heat transfer is instant along with rapid heat transfer cells can get very warm or hot. So best to charge/discharge cells so they are all the same voltage. 2. If a cell fails or is weak then the other 3 in P...
by hemo
Jun 29 2019 6:07pm
Forum: Battery Technology
Topic: BMS On/Off switch wires?
Replies: 12
Views: 1582

Re: BMS On/Off switch wires?

Switch on when charging and off when not in use.
by hemo
Jun 19 2019 1:43pm
Forum: Battery Technology
Topic: What connector is this please?
Replies: 5
Views: 300

Re: What connector is this please?

Yes looks like Anderson type.
by hemo
Jun 18 2019 1:02pm
Forum: Battery Technology
Topic: oups i dremeled my cel to deep damaged??
Replies: 8
Views: 488

Re: oups i dremeled my cel to deep damaged??

The discolouring/ change of wrap colour is between wrap and cell can, it is looks like electrolyte has seeped vented out, if they smell bin them. The rust on the neg end is indictive of venting/electrolyte seepage.
by hemo
Jun 18 2019 12:41pm
Forum: Battery Technology
Topic: 13s4p battery build - does this look correct?
Replies: 1
Views: 221

Re: 13s4p battery build - does this look correct?

Why not change/reverse the cells 8 -13 so that 8 is next to 7, then just use short series buss between the two on the top row. The buss will be the same length as all the others ,the short buss will have less resistance and voltage loss then the 10awg one end to the other. Also instead of using the ...
by hemo
Jun 08 2019 5:14am
Forum: Battery Technology
Topic: Lifepo4 charging - 2 x 12S2P
Replies: 6
Views: 365

Re: Lifepo4 charging - 2 x 12S2P

With BMS separately at 36v.
by hemo
Jun 03 2019 3:59am
Forum: Battery Technology
Topic: BOSS LEVEL CUSTOM SPOT WELDER
Replies: 438
Views: 43469

Re: BOSS LEVEL CUSTOM SPOT WELDER

Seems like I have run into the same issue as Hemo. I will need to take apart the spot welder and check my Arduino board ... if it is indeed the same problem, I may end up replacing the board myself and getting the files from Aulakiria. I'll be back if it is another problem ... My new upper Arduino ...
by hemo
Jun 02 2019 4:03am
Forum: Battery Technology
Topic: trouble sourcing a 7s bms
Replies: 16
Views: 608

Re: trouble sourcing a 7s bms

Have a look at this one to see if it will do the job for you.

https://www.aliexpress.com/item/Waterpr ... 4c4dqBDFgq
by hemo
May 21 2019 2:50pm
Forum: Battery Technology
Topic: Charger strange behaviour (53.5V)
Replies: 18
Views: 588

Re: Charger strange behaviour (53.5V)

The charger will be a simple dumb charger it only supplies charge voltage if the BMS allows it to,the charger doesn't dictate the charging it just responds to the BMS which will or will not except a charge voltage. The switch is linked to the balance side of the BMS and typically the balance occurs ...
by hemo
May 13 2019 4:49pm
Forum: Battery Technology
Topic: Which high capacity 18650 cell for 250w ebike battery pack with heavy usage?
Replies: 35
Views: 1369

Re: Which high capacity 18650 cell for 250w ebike battery pack with heavy usage?

EU regs I think do state 48v max but no one for sure knows if that is a nominal voltage or not. UK seller Woosh sell 250w 48v nom kits so they have taken the regs as nominal. I would be inclined to use 22 or 25a KT 9 FET dual volt sinewave controller, the 6 fet ones tend to get very hot in hilly ter...
by hemo
May 13 2019 10:56am
Forum: Battery Technology
Topic: Which high capacity 18650 cell for 250w ebike battery pack with heavy usage?
Replies: 35
Views: 1369

Re: Which high capacity 18650 cell for 250w ebike battery pack with heavy usage?

vulcanears wrote:
May 10 2019 8:11am
The controller is 7A continuous, 15A peak. (Which is the legal limit in the EU)
Can you show the regs that state 15a peak is the legal limit afaik the only regs are motor has to rated 250w and max 48v. Not see any stipulated figures for contoller amps.
by hemo
May 13 2019 10:51am
Forum: Battery Technology
Topic: Which high capacity 18650 cell for 250w ebike battery pack with heavy usage?
Replies: 35
Views: 1369

Re: Which high capacity 18650 cell for 250w ebike battery pack with heavy usage?

I'm not to far north of you the pic of Arkose is at Ardingly reservoir. I'm fully acquainted with Brighton and it's hilly climbs and is a part of a regular circuit of mine for riding. I would if living locally and able to swap over/recharge is go light as possible no use dragging heavy bike up hills...
by hemo
May 12 2019 4:12am
Forum: Battery Technology
Topic: Which high capacity 18650 cell for 250w ebike battery pack with heavy usage?
Replies: 35
Views: 1369

Re: Which high capacity 18650 cell for 250w ebike battery pack with heavy usage?

I use Pinnacle Arkose for day rides out and use a 24v friction dive, battery is 208wh PF cells for lighter weight bike. With 700m of climbing I can get about 26 miles range and carry a spare battery in the seat bag. Battery and drive 2.5kg added to bike. DSCF0976.JPG For cycle delivery locally think...
by hemo
May 10 2019 4:20am
Forum: Battery Technology
Topic: Bms shuts down at 30v and then won't charge
Replies: 5
Views: 289

Re: Bms shuts down at 30v and then won't charge

32/33v min discharge. The bms will look at total accumulated voltage across whole battery, going to 30v means one cell group or more went below 3v and remained so at rest and bms then wouldn't then allow the charging process to begin. The fact you by passed the bms to increase the voltage then recom...
by hemo
May 06 2019 5:50pm
Forum: Battery Technology
Topic: Is it safe to seal batteries in a waterproof plastic food container?
Replies: 22
Views: 891

Re: Questions about using older chargers.

Most of the basic China plastic 2a chargers have a trim port/potentometer inside so you can adjust the voltage if you have a meter that you know to be quite accurate. I have adjusted mine and also find they are good for storage voltage for 13s, adjust to 50v and you get a tad under 3.85v per cell fo...
by hemo
Apr 24 2019 4:20pm
Forum: Battery Technology
Topic: Speedict neptune lite
Replies: 84
Views: 9488

Re: Speedict neptune lite

For better cell cycle life charge to a lower voltage 53.6 = a tad over 4.12v per cell.
by hemo
Apr 23 2019 4:35pm
Forum: Battery Technology
Topic: XT90 connectors stuck
Replies: 11
Views: 772

Re: XT90 connectors stuck

montana2436 wrote:
Apr 22 2019 6:41am
Thanks. When installing new connectors, would wrapping wires around each other be sufficient or welding them would be better?


Solder the wiring, don't rely on wrapping any wiring.
by hemo
Apr 20 2019 5:06pm
Forum: Battery Technology
Topic: 72V Hailong packs, can run 2 paralleled?
Replies: 5
Views: 367

Re: 72V Hailong packs, can run 2 paralleled?

No reason why they can't be used in parallel, just make sure both voltages are as close as possible before connecting together.
by hemo
Apr 15 2019 3:07am
Forum: Battery Technology
Topic: battery won't charge
Replies: 4
Views: 227

Re: battery won't charge

I would ride and discharge the pack some then resume again with a full balance charge.
Next time before you leave the battery for such a long time consider leaving it in a more discharged state to about 50v.
by hemo
Apr 10 2019 5:29am
Forum: Battery Technology
Topic: BMS questions!
Replies: 5
Views: 395

Re: BMS questions!

A simple reply. 1. Bulk charging requires closer monitoring, if cells are all good then they should charge close to within reason. For bulk charging use a lower terminal top voltage so not to over charge and monitor cell charging. 2. Dosen't matter their colour, most bms board jst are marked B-/B0 f...