Search found 173 matches

by hemo
Feb 17 2020 10:34am
Forum: Battery Technology
Topic: Bosch powertube repair
Replies: 5
Views: 144

Re: Bosch powertube repair

Jimmy in London at ebikebatteries.co.uk I believe parallels the BMS to another source (likey the new cell pack) once this is done the old cells can be disconnected. Though if a cell group is toast the BMS may well be bricked.
He recelled my brothers Bosch pack but that was a Gen 1 or 2 pack.
by hemo
Feb 13 2020 7:54am
Forum: E-Bike General Discussion
Topic: Small hub motor
Replies: 21
Views: 1790

Re: Small hub motor

I have been interested in building a small hub motor ebike as a road bike conversion. I have been an off and on bike rider, so have a road bike that I am looking to augment with a small motor to give it an occasional boost (throttle only), but intend to ride it 99% of the time on pedal only. As suc...
by hemo
Feb 11 2020 12:35pm
Forum: Battery Technology
Topic: BMS not charging or discharging
Replies: 40
Views: 816

Re: BMS not charging or discharging

Tbh that BG BMS isn't conducive for great cell cycle life, lvc detection/release is to deep.
by hemo
Feb 08 2020 7:05pm
Forum: Battery Technology
Topic: Would anyone have specs on this cell?
Replies: 42
Views: 981

Re: Would anyone have specs on this cell?

Yes it was a typo on my part, I have modified the post to reflect the error.
by hemo
Feb 08 2020 8:32am
Forum: Battery Technology
Topic: Would anyone have specs on this cell?
Replies: 42
Views: 981

Re: Would anyone have specs on this cell?

From my experience the top 0.1v carries little capacity ( In a typical 10s5p or 13s 5p pack) and certainly no where near 10% of cell capacity or range. I find within 1 -1.5 miles that any voltage if charged to 4.2v is used up very quickly and cells are down to 4.1v or there abouts. For the sake of s...
by hemo
Feb 05 2020 5:50pm
Forum: Battery Technology
Topic: Adding one battery in parallel to 5 serial connected battery pack
Replies: 15
Views: 363

Re: Adding one battery in parallel to 5 serial connected battery pack

Of course a brand new one, otherwise identical, would be even better. Do a comparative capacity test using a CC load, your new-to-you pack might be NOS barely worn, or it could be in worse shape than your old one. Is this connection ok? https://i.hizliresim.com/ryBjGN.jpg NO. You are trying to para...
by hemo
Jan 31 2020 7:14pm
Forum: Battery Technology
Topic: Paralleling uneven voltage cells?
Replies: 43
Views: 1140

Re: Paralleling uneven voltage cells?

The transfer will be instant between the two and very very hot, I don't know the math involved but someone else more knowledgable will.
by hemo
Dec 20 2019 7:30pm
Forum: Battery Technology
Topic: 13$ battery spot welder testing out
Replies: 15
Views: 1799

Re: 13$ battery spot welder testing out

It's not meant as a criticism of the Welder as it is only a few dollars but more to be wary if trying to weld together an ebike usable battery, the battery will be a liability and with poor welded interconnectors that will fail easily.
by hemo
Dec 17 2019 11:55am
Forum: Battery Technology
Topic: 13$ battery spot welder testing out
Replies: 15
Views: 1799

Re: 13$ battery spot welder testing out

Tbh none of those welds were very strong, the ease at which they were pulled apart using only your fingers showed that.
by hemo
Dec 08 2019 6:28am
Forum: Battery Technology
Topic: 36 V pack not charging
Replies: 16
Views: 1131

Re: 36 V pack not charging

For welding you have to know a friendly ebiker/battery builder who can help you out or go diy, make one as in various threads on the forum which forumites have done or buy a ready built one. Malectrics , Kweld & Boss hand held welders all work well, the downside is the expense if only for a one off....
by hemo
Dec 07 2019 7:39pm
Forum: Battery Technology
Topic: 36 V pack not charging
Replies: 16
Views: 1131

Re: 36 V pack not charging

Hello Amaurer, Yes B1 is toast. The BMS has allowed it to deplete, likely a faulty bleed resistor. Luckily B1 & B10 are the easiest groups to replace, I would also replace the BMS. Ann battery on Aliexp I have always found to sell good basic BMS, I usually opt for ones with the added switch wiring a...
by hemo
Dec 06 2019 7:25pm
Forum: Battery Technology
Topic: 36 V pack not charging
Replies: 16
Views: 1131

Re: 36 V pack not charging

40v isn't too good, so sounds like one cell group is low (< 3 or 3.1v) in which case the BMS you can see will not switch to allow the charger to do it's job. On the BMS you will see the parallel group sense wire connector (usually white) with 11 wires for 36v, you need to unplug it (might be tight f...
by hemo
Oct 30 2019 6:35pm
Forum: Battery Technology
Topic: Lipo slightly puffy
Replies: 32
Views: 2535

Re: Lipo slightly puffy

It will most likely charge ok but use a low charge rate and monitor it for heat, certainly don't leave it to is own devices during charging and only outside. The other issue is puffed cells will have a higher IR which means the cell will sag and beat the other cells to lvc quicker, capacity/range wi...
by hemo
Oct 04 2019 3:41pm
Forum: Battery Technology
Topic: low batter voltage cutoff.
Replies: 26
Views: 860

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: 471

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: 1350

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: 678

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: 347

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: 2058

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: 412

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: 630

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: 282

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: 490

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: 448
Views: 51658

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 ...