Search found 212 matches

by kcuf
Mar 23 2021 5:25pm
Forum: EBike Build Threads
Topic: Hub motor as mid (illegalbike) 6000W / 33kg
Replies: 134
Views: 9166

Re: Hub motor as mid (illegalbike)

only illegal if you get caught

nice skills and workmanship
by kcuf
Feb 25 2021 10:51am
Forum: Battery Technology
Topic: BMSs
Replies: 11
Views: 414

Re: BMSs

parallel groups - series strings parallel groups behave as 1 large cell wired in series to form a string to achieve desired pack voltage bms requires wire connection to each series string point which protect the parallel group example 2p14s describes 2 cells in parallel (capacity Ah/Wh) wired in 14 ...
by kcuf
Feb 25 2021 10:40am
Forum: Battery Technology
Topic: Safe RC-LiPo undercharge when bulk charging without BMS?
Replies: 17
Views: 483

Re: Safe undercharge for LiPo for bulk charge without BMS?

good cells 4.2 is okay

don’t let sit there for long

use almost immediately

reduces degradation


not sure when next use

stop around 4.0-4.1

then quickly top off

for full capacity if needed


50% dod is smart money
by kcuf
Feb 22 2021 1:09am
Forum: Battery Technology
Topic: Trying to increase my batteries longevity but did i actually destroy it doing so?
Replies: 22
Views: 724

Re: Trying to increase my batteries longevity but did i actually destroy it doing so?

sometimes it can take weeks

60-80mA isn't much energy dissipation

especially poorly balanced series strings

and you also need charger that

restarts charging after bleeding down

and bms resumes charging

not all chargers do this
by kcuf
Jan 28 2021 2:14pm
Forum: EBike Technical
Topic: BMS Bypass OK?
Replies: 18
Views: 1008

Re: BMS Bypass OK?

why i prefer bypass these bms

too goofy for operational reliability
by kcuf
Jan 28 2021 2:06pm
Forum: EBike Non-hub Motor Drives
Topic: BBSHD Controller Reliability
Replies: 2
Views: 375

Re: BBSHD Controller Reliability

"throttle for top speed runs"

never good idea any bbsxx

short bursts 100% power only


understand controller peaks around 1500w

design rated 1000w continuous


enable 9 power levels

ride all day level 7 or below

8, 9 or full throttle is gamble
by kcuf
Jan 24 2021 2:16pm
Forum: Battery Technology
Topic: Self-Discharge UPDATE On 30Q 141 Cells
Replies: 84
Views: 4314

Re: Self-Discharge UPDATE On 30Q 141 Cells

3qty 30Q packs here

2 used cold freezing weather

both dead less than year

most cells exhibit self discharge


1 pack mild weather

3 yrs going strong

no measurable self discharge


coincidence? possibly

but now refrain from

below 50F charge
by kcuf
Jan 23 2021 11:23am
Forum: EBike Technical
Topic: BMS Bypass OK?
Replies: 18
Views: 1008

Re: BMS Bypass OK?

no b22
by kcuf
Jan 21 2021 1:37pm
Forum: EBike Non-hub Motor Drives
Topic: reliable middrive for commute?
Replies: 21
Views: 1139

Re: reliable middrive for commute?

more limited choices bbs 02 vs hd

smallest front ring better 44t if option


cassette cogs may be readily changeable

freewheel cluster cogs not so easy


most riders will never

need more than

3-5 gear options
by kcuf
Jan 20 2021 8:06pm
Forum: EBike Technical
Topic: BMS Bypass OK?
Replies: 18
Views: 1008

Re: BMS Bypass OK?

that damn bms feature

causes many unhappy users


for my herd

often bypass bms power load path

no switch though

load power straight from tabs

only charge power through bms

much smaller/cheaper bms charge only


outdoor discharge

using conservative controller lvc

often safe enough
by kcuf
Jan 20 2021 7:57pm
Forum: EBike Non-hub Motor Drives
Topic: reliable middrive for commute?
Replies: 21
Views: 1139

Re: reliable middrive for commute?

personally use cheap $10-$12 chains

between 1-2k miles before seeing measurable wear


avoid small rear cogs

especially 11t


use a chain wear gauge/tool regularly

swap for a new chain any measured wear

doing so greatly reduces cog wear
by kcuf
Jan 04 2021 10:08pm
Forum: EBike Technical
Topic: Battery won't charge
Replies: 14
Views: 357

Re: Battery won't charge

many bms die easily

high power gets expensive

consider low power charge bms only

discharge directly off tabs



outdoor battery discharge

no bms usually safe enuf

controller lvc should match 14s



cheap ebay solution

10-20A 14s bms wired charge only
by kcuf
Jan 02 2021 2:35pm
Forum: EBike Technical
Topic: Battery won't charge
Replies: 14
Views: 357

Re: Battery won't charge

what is the voltage of the charger

label isn't marked

use volt meter and measure

charger output not connected to battery

if 54v and change?

wrong charger

if 58v and change

something else wrong
by kcuf
Dec 16 2020 8:11pm
Forum: EBike Technical
Topic: Trio Cargo e-bike mid drive
Replies: 37
Views: 1525

Re: Trio Cargo e-bike mid drive

use different bike

and bbshd
by kcuf
Dec 16 2020 8:08pm
Forum: Forum Rules and Features
Topic: How do you feel about 'other toxic discussions' on this forum?
Replies: 39
Views: 2442

Re: How do you feel about 'other toxic discussions' on this forum?

otd great for trolls

instabilities made visible

divisions sowed

no point on technical forum
by kcuf
Nov 15 2020 5:27pm
Forum: EBike General Discussion
Topic: Your thoughts on frames and riding positions?
Replies: 39
Views: 1947

Re: Your thoughts on frames and riding positions?

tried everything went fat tire years ago 10-13psi soak up harsh pavement nothing complicated or too costly good shocks/forks expensive and sucks mounting battery limited tire tread choices tho vee rubber makes rib tread for felt low pressure fat tires handle all terrain stepper seat post offers both...
by kcuf
Nov 14 2020 9:31am
Forum: EBike Reviews & Testing
Topic: What the heck is wrong with UPP packs!?
Replies: 66
Views: 4256

Re: What the heck is wrong with UPP packs!?

motor wattage continuous

not peak rating


never seen 30a bms peak 90a

more like 40-50a if that


multiple problems here

overloading is bad as evidenced here

water only makes things worse
by kcuf
Nov 02 2020 7:53pm
Forum: EBike Technical
Topic: Help with unknown ebike controler repair
Replies: 9
Views: 564

Re: Help with unknown ebike controler repair

pictures will be your friend
by kcuf
Nov 01 2020 2:09pm
Forum: EBike General Discussion
Topic: 52 volt batteries proceed with caution
Replies: 27
Views: 2220

Re: 52 volt batteries proceed with caution

emp raises valid point

48v packs poorly modified to 52v


human nature likes snappy 52v

warrantied bbsxx installs only use 48v


bbsxx internal gearing skewers @ higher motor rpm

use shorter cranks to compensate
by kcuf
Oct 16 2020 10:24am
Forum: EBike Non-hub Motor Drives
Topic: How do you size the right Mid Drive?
Replies: 36
Views: 1126

Re: How do I size the proper mid-drive for off road use?

carry chain breaker and spare links + master

if when derailleur craps

or chain breaks

can usually rework chain

for limp mode


chain lube over rated

measure chain wear

replace $10-$15 chain showing minor wear
by kcuf
Oct 16 2020 10:21am
Forum: EBike General Discussion
Topic: Off Road Battery Case what do you use?
Replies: 7
Views: 365

Re: Off Road Battery Case what do you use?

using secured padding

triangle bag is great choice
by kcuf
Oct 15 2020 7:09pm
Forum: EBike Non-hub Motor Drives
Topic: How do you size the right Mid Drive?
Replies: 36
Views: 1126

Re: How do I size the proper mid-drive for off road use?

bbshd = bbs03

somewhat more rugged

hd about 3lbs heavier than 02

hd motor seemingly less efficient windings


hd likely hold up better off roading


can be found in wider BB spacing too

fat tire bikes hmm