Search found 606 matches

by dmwahl
Nov 14 2018 11:32am
Forum: Items for Sale - New
Topic: Hybrid Power 2WD E-Bike Project Development
Replies: 9
Views: 614

Re: Hybrid Power 2WD E-Bike Project Development

Although I will admit the picture on the gogetfunding page of the electronics with the multicolored explosion background had me convinced for a while, this is just another HHO, free energy, etc scam. You can't get more energy out of water by splitting it into hydrogen/oxygen and then recombining it ...
by dmwahl
May 08 2018 2:12pm
Forum: Battery Technology
Topic: Yet another BMS
Replies: 67
Views: 10285

Re: Yet another BMS

Did you have to duplicate the read process? I haven't had any issues reading from the ROM with only a single write. I have a 1ms wait between sending the address byte to read and doing the actual read since the datasheet says it takes ~200us to read from ROM, but I didn't need to do the read twice. ...
by dmwahl
May 07 2018 3:07pm
Forum: Battery Technology
Topic: Yet another BMS
Replies: 67
Views: 10285

Re: Yet another BMS

is it normal have disconnect the battery to save values in ROM? No, there's a process to write to ROM detailed in one of the app notes. I forget the details but as I recall it's basically the following steps with a wait between them to allow it to actually do the write. 1) Enable EEPROM access 2) W...
by dmwahl
Mar 22 2018 6:47am
Forum: Items for Sale - New
Topic: Heavy Duty Torque Arm - Disc mount, clamping optional $35
Replies: 93
Views: 14754

Re: Heavy Duty Torque Arm - Disc mount, clamping optional $35

cwah wrote:
Mar 21 2018 7:28pm
Do you still have for sale? Thanks
Yep, plenty available. I ordered a whole bunch of them and they’ve been selling regularly. I should probably post periodically so people know they’re still available.
by dmwahl
Oct 14 2017 9:56pm
Forum: Items for Sale - New
Topic: Heavy Duty Torque Arm - Disc mount, clamping optional $35
Replies: 93
Views: 14754

Re: Heavy Duty Torque Arm - Disc mount, clamping optional $3

A single arm seems to be the most common, just based on the fact that maybe 80% of people only order 1. Maybe they're using a different one for the other side, but I don't think 2 are necessary for most people. Then again I like selling 2 at a time, so maybe just order 2 to be on the safe side :)
by dmwahl
Oct 14 2017 7:45pm
Forum: Items for Sale - New
Topic: Heavy Duty Torque Arm - Disc mount, clamping optional $35
Replies: 93
Views: 14754

Re: Heavy Duty Torque Arm - Disc mount, clamping optional $3

shorza wrote:What are people doing for the non disk side? Has anyone DP420 epoxied these torque arms to the frame?
It wasn't the intent of the design to epoxy them, but if you look a few posts above this one someone was planning on doing just that. Perhaps he will chime in here...
by dmwahl
Oct 05 2017 2:01pm
Forum: Items for Sale - New
Topic: Heavy Duty Torque Arm - Disc mount, clamping optional $35
Replies: 93
Views: 14754

Re: Heavy Duty Torque Arm - Disc mount, clamping optional $3

About clamping.. i don't really think u can clamp a 9.5mm of harden steel You can actually get a measurable deflection using a M6 screw and hand tightening it. Whether or not it's needed is another matter altogether, but I've measured several tenths of a mm deflection when tightening the clamping b...
by dmwahl
Jun 28 2017 12:35pm
Forum: Items for Sale - New
Topic: Heavy Duty Torque Arm - Disc mount, clamping optional $35
Replies: 93
Views: 14754

Re: Heavy Duty Torque Arm - Disc mount, clamping optional $3

I don't think these here will work on front fork...? If I am wrong please correct me. This was resolved via PM, but for the benefit of everyone else the torque arm was designed for a rear fork, but there's no fundamental reason it wouldn't work on a front fork. The angle of the flats relative to th...
by dmwahl
Apr 21 2017 8:46am
Forum: Items for Sale - New
Topic: Heavy Duty Torque Arm - Disc mount, clamping optional $35
Replies: 93
Views: 14754

Re: Heavy Duty Torque Arm - Disc mount, clamping optional $3

Swe wrote:I would like to buy one for front fork IS. Have sent PM but don't think you have read it yet.
I don't see any PMs from you, try again perhaps?
by dmwahl
Apr 04 2017 8:53am
Forum: Items for Sale - New
Topic: Heavy Duty Torque Arm - Disc mount, clamping optional $35
Replies: 93
Views: 14754

Re: Heavy Duty Torque Arm - Disc mount, clamping optional $3

pwd wrote:...fabri-cobble...
Haven't heard that one before, I'm going to have to borrow it from now on.
by dmwahl
Mar 25 2017 7:52pm
Forum: Items for Sale - New
Topic: Heavy Duty Torque Arm - Disc mount, clamping optional $35
Replies: 93
Views: 14754

Re: Heavy Duty Torque Arm - Disc mount, clamping optional $3

rich43 wrote:I paid but sent two $50 payments by mistake as PayPal glitched, can you refund one and keep the other as payment for the torque arm?
Done.
by dmwahl
Mar 25 2017 1:50pm
Forum: Items for Sale - New
Topic: Heavy Duty Torque Arm - Disc mount, clamping optional $35
Replies: 93
Views: 14754

Re: Heavy Duty Torque Arm - Disc mount, clamping optional $3

rich43 wrote:I have sent you a PM, I am interested in ordering one. :)
Replied.
by dmwahl
Mar 22 2017 1:51pm
Forum: Items for Sale - New
Topic: Heavy Duty Torque Arm - Disc mount, clamping optional $35
Replies: 93
Views: 14754

Re: Heavy Duty Torque Arm - Disc mount, clamping optional $3

rich43 wrote:Are these still for sale?
You bet. I have stock and have been getting them in the mail within a day or two of ordering.
by dmwahl
Nov 07 2016 2:41pm
Forum: Items for Sale - New
Topic: Heavy Duty Torque Arm - Disc mount, clamping optional $35
Replies: 93
Views: 14754

Re: Heavy Duty Torque Arm - IS mount, clamping optional $35

999zip999 wrote:Does it fit a diamond back response ? It looks like it.
Can't say for sure, I only have room for so many bikes... Print out the template on the first post and that will tell you.
by dmwahl
Oct 20 2016 4:04pm
Forum: Battery Technology
Topic: Issue with Headway 40152 battery pack
Replies: 11
Views: 1013

Re: Issue with Headway 40152 battery pack

There's likely some damage to the 0V cells, but not necessarily enough to be a problem. LFP is more tolerant of abuse than some of the other Li-ion varieties. The longer you wait to recharge them the worse the problem will be. I've done the same accidentally on my lawnmower pack (8S2P, headway LFP)....
by dmwahl
Oct 18 2016 2:50pm
Forum: Battery Technology
Topic: BMS 12 AWG enough?
Replies: 12
Views: 752

Re: BMS 12 AWG enough?

Oh ok, so I missed the part with the shunt, so they thicken up the shunt to pass more current and then also thicken up the traces to handle the extra current the shunt will pass right? The shunt is just a precise, low value resistor. The controller measures the voltage across the shunt to calculate...
by dmwahl
Oct 18 2016 12:34pm
Forum: Battery Technology
Topic: BMS 12 AWG enough?
Replies: 12
Views: 752

Re: BMS 12 AWG enough?

But don't thinner wires able to transfer less amps since they have only limited amount of surface (thickness) to them to transfer the 80A (for that example)? There's no real limit to how much current the wire can carry, as long as it's not enough to damage the wire. You could send 1000A through 32a...
by dmwahl
Oct 17 2016 1:07pm
Forum: Battery Technology
Topic: BMS 12 AWG enough?
Replies: 12
Views: 752

Re: BMS 12 AWG enough?

As far as peak current, it doesn't depend on wire length, it's just a matter of power per unit length, and how well the wire can shed heat without getting too hot. The problem comes when you start either overheating something or wasting a significant portion of your total power in anything other tha...
by dmwahl
Oct 14 2016 9:47am
Forum: Battery Technology
Topic: BMS 12 AWG enough?
Replies: 12
Views: 752

Re: BMS 12 AWG enough?

10awg is ~1mOhm/foot, 12awg is ~1.6mOhm/foot. Since P=R*I^2, 45A will dissipate ~2W/foot for 10awg and ~3.2W/foot for 12awg. Compared to 3kW total, it's not likely to matter much to performance. Personally I have an 18S pack using 12awg, and no issues up to 80A peak.
by dmwahl
Oct 05 2016 12:46pm
Forum: Battery Technology
Topic: Thundersky Cell Motor Freight Questions
Replies: 15
Views: 793

Re: Thundersky Cell Motor Freight Questions

I've received batteries via UPS freight, up to 8 100Ah LFP cells in a pack. Nothing special, just talk to them about what you want to do. Otherwise something like uship.com might be an option, I don't know if they have specific rules on hazardous freight, but you can ship a car with a full gas tank.
by dmwahl
Oct 04 2016 9:39pm
Forum: Battery Technology
Topic: 13.6v AC charger?
Replies: 14
Views: 949

Re: 13.6v AC charger?

I'll second the meanwell recommendation. They're sometimes used in commercial LFP pack designs as battery chargers, set around 3.45V/cell for float use. There are also lots of meanwell clones on ebay, amazon, etc. I've got a 25W 12V clone I got on Amazon for ~$10, bought it for a 200Ah GBS pack almo...
by dmwahl
Sep 28 2016 4:58pm
Forum: Items for Sale - New
Topic: Heavy Duty Torque Arm - Disc mount, clamping optional $35
Replies: 93
Views: 14754

Re: Heavy Duty Torque Arm - IS mount, clamping optional $35

Yes, definitely helpful to know what it fits on. Thanks for posting yours. I like the black paint, makes it blend in nicely.

Regarding the rust, a few of them have some, I believe due to the cutting process. They're stainless steel though so any corrosion will be minimal.
by dmwahl
Sep 19 2016 10:37am
Forum: Battery Technology
Topic: DIY BMS Help
Replies: 8
Views: 978

Re: DIY BMS Help

As I recall there are all sorts of rules for the FSAE. I was part of it in college, as well as the hybrid vehicle team, and for some parts the rules are such that they basically force you into a specific voltage if you want a fighting chance. Like max power, max battery voltage, max fused current, e...
by dmwahl
Sep 18 2016 8:36pm
Forum: Battery Technology
Topic: DIY BMS Help
Replies: 8
Views: 978

Re: DIY BMS Help

Old laptop cells aren't intended for high current even when they're new. You'll need a huge pack to get any decent power and then the weight and size may be a problem. I'd suggest checking out okashira's sale thread for Tesla cells. He can build the pack for a very reasonable price and they're good ...