Search found 31064 matches

by amberwolf
Jan 18 2022 9:25am
Forum: Battery Technology
Topic: Looking for recommendation: 20s 40-60A smart BMS with 5 or more NTC inputs
Replies: 6
Views: 135

Re: Looking for recommendation: 20s 40-60A smart BMS with 5 or more NTC inputs

Thanks for the tip; I didn't realize bimetal switches came in such small size and cost. Those should work. I could save on wiring by connecting them in series with the balance wires, so that if any one of them trips, the BMS thinks the battery is off kilter and shuts down. That'd give me four sensi...
by amberwolf
Jan 18 2022 12:21am
Forum: Battery Technology
Topic: Looking for recommendation: 20s 40-60A smart BMS with 5 or more NTC inputs
Replies: 6
Views: 135

Re: Looking for recommendation: 20s 40-60A smart BMS with 5 or more NTC inputs

If you don't actually need to monitor the temperature, just shut off if any box reaches a specified temperature, you can use a series-wired array of thermal switches in place of the single one that's often used on small BMS boards. In theory, you could wire as many as necessary in series to even mon...
by amberwolf
Jan 18 2022 12:10am
Forum: EScooters/EMotorcycles
Topic: Overvolt 2000w 45A 48v motor to 60v 33A-35A or swap controller for bigger amps
Replies: 16
Views: 1529

Re: Overvolt 2000w 45A 48v motor to 60v 33A-35A or swap controller for bigger amps

But which mode does yours use? (Kelly can factory change the modes of some of theirs even though the end-user can't).

Which testing method are you using?

I don't know that it has anything to do with your results, but it's something to eliminate.
by amberwolf
Jan 18 2022 12:06am
Forum: Battery Technology
Topic: Burnt BMS (Pics included) Please help?
Replies: 25
Views: 475

Re: Burnt BMS (Pics included) Please help?

Curious but why does it state in the title "constant current" ? Is this just reffering to CC/CV charging? If you mean the " 40A constant discharge current " in the item name at the top right, then that matches this spec further down (and also in the attached chart) Brand Name: L...
by amberwolf
Jan 17 2022 11:57pm
Forum: Battery Technology
Topic: Burnt BMS (Pics included) Please help?
Replies: 25
Views: 475

Re: Burnt BMS (Pics included) Please help?

Yes thats correct. I've put the multimeter to 20 vdc and i'm seeing anywhere between 0.00-0.02 difference between each pair. Just to be sure, this is a different set of measurements than previously done? I'm checking, because the results are definitely different than 3.4-3.5v per cell, and it makes...
by amberwolf
Jan 17 2022 11:46pm
Forum: Battery Technology
Topic: Need advice for Bafang battery
Replies: 7
Views: 130

Re: Need advice for Bafang battery

Sorry about the link https://bafangusadirect.com/collections/motor-kits/products/complete-bafang-1000w-bbshd-mid-drive-ebike-motor-kit-battery For the specs on that page Up to 1,764 watts with 52V battery (1,638 watts with 48V battery) 45 amp Anderson Connections to connect to battery it means you ...
by amberwolf
Jan 17 2022 11:38pm
Forum: Battery Technology
Topic: Need advice for Bafang battery
Replies: 7
Views: 130

Re: Need advice for Bafang battery

Sorry about the link https://bafangusadirect.com/collections/motor-kits/products/complete-bafang-1000w-bbshd-mid-drive-ebike-motor-kit-battery regarding the battery there is not much information and specifications. I'm struggling with the idea of how much is 1 amp. I know there are formulas and stu...
by amberwolf
Jan 17 2022 10:33pm
Forum: Battery Technology
Topic: Any stores that sell parts for batteries?
Replies: 2
Views: 57

Re: Any stores that sell parts for batteries?

I've been looking for a store in my city where I can buy all the parts to put together a battery, and so far I've found somewhere to buy 18650 batteries. What kind of places do people go to for parts? We have no idea where you are, beyond "Australia" (in your profile), so we can't really ...
by amberwolf
Jan 17 2022 9:27pm
Forum: Battery Technology
Topic: Burnt BMS (Pics included) Please help?
Replies: 25
Views: 475

Re: Burnt BMS (Pics included) Please help?

Being curious (and trying to grow more comfortable with the battery) i decided to measure the balance lead voltages, which gave me 3.5 to 3.4v variance increases going up each bank Is this a good sign? Would I be right in thinking this shows that the battery cells are at least pretty well balanced?...
by amberwolf
Jan 17 2022 8:01pm
Forum: EBike Technical
Topic: How do I wire up 12v headlight on Sabvoton 72100
Replies: 1
Views: 59

Re: How do I wire up 12v headlight on Sabvoton 72100

You'll need a DC-DC converter that can output the current your headlight requires, at minimum, that takes it's output from your main battery's output. If you use the headlight all the time, just wire the DC-DC input side to the battery on the controller side of the main battery power switch (if you ...
by amberwolf
Jan 17 2022 7:25pm
Forum: EBike Troubleshooting
Topic: Bike works while plugged in
Replies: 5
Views: 151

Re: Bike works while plugged in

so this is what i got. voltage out of the main +/- wire 78.4V voltage read from the red positive voltage wire. 3.267 6.535 9.80 13.07 16.34 19.61 22.88 26.14 29.41 32.68 35.95 39.21 42.48 45.75 49.02 52.29 55.56 58.83 62.09 65.36 68.6 71.9 75.2 78.4 I tried to get lower voltage numbers. They were a...
by amberwolf
Jan 17 2022 6:49pm
Forum: Battery Technology
Topic: BMS parallel setup: 2 batteries 1 controller
Replies: 13
Views: 178

Re: BMS parallel setup: 2 batteries 1 controller

GumbaLL wrote:
Jan 17 2022 2:37am

Experienced DC power engineers are tough to find in my neck of the woods, and gotta try asking when there are alot of good smart ppl online :D
There are places online you can hire one. Remember that the free advice you get on forums and whatnot is worth every penny it costs. :P
by amberwolf
Jan 17 2022 6:47pm
Forum: Battery Technology
Topic: BMS parallel setup: 2 batteries 1 controller
Replies: 13
Views: 178

Re: BMS parallel setup: 2 batteries 1 controller

So maybe a good BMSs would simply do it. LVC kicks in on the battery that is low SoC and for extra measure a MCU programmed to switch if off No. The BMS LVC won't do anything for you in the situation you're creating, because the low pack is being charged, so voltage is increasing, not decreasing. I...
by amberwolf
Jan 17 2022 6:20pm
Forum: Battery Technology
Topic: Burnt BMS (Pics included) Please help?
Replies: 25
Views: 475

Re: Burnt BMS (Pics included) Please help?

By both directions i assume you mean reversing the multimeter cables on the drain/source? In which case i get the same result. THen the FET appears shorted, and could not be used to control charge. I was hoping to find replacements that at least exceed the quality of this BMS but i suppose thats al...
by amberwolf
Jan 17 2022 5:50pm
Forum: Battery Technology
Topic: fake molicel cells? QR code question
Replies: 4
Views: 180

Re: fake molicel cells? QR code question

I'd test them to see if they are at least useful, and if not, then you can replace them.

Either way I'd post the results here, along with a link to the seller page, so others can at least know who they are. Up to them if they avoid or buy.
by amberwolf
Jan 17 2022 5:48pm
Forum: Battery Technology
Topic: EFEST brand name cells
Replies: 3
Views: 100

Re: EFEST brand name cells

If it were me, I'd test what you have in the other thread first, to see if they're useful or not, despite probably not being the cells you actually ordered. If they turn out to be good enough, you're all set; if not, then I'd recommend buying only from places that others have recently bought from an...
by amberwolf
Jan 17 2022 12:16am
Forum: Battery Technology
Topic: Burnt BMS (Pics included) Please help?
Replies: 25
Views: 475

Re: Burnt BMS (Pics included) Please help?

So i checked the voltage of the burnt out FET between the source and the drain (the tab at the top of the fet itself) and it measured 0 voltage, so i then did a continuity test and got a positive/beep. Based on this, I guess the fet has failed on and would charge the pack to annihilation given the ...
by amberwolf
Jan 16 2022 11:57pm
Forum: Battery Technology
Topic: BMS parallel setup: 2 batteries 1 controller
Replies: 13
Views: 178

Re: BMS parallel setup: 2 batteries 1 controller

20 balance wires to one cell group and 20 balance wires to another cell group. From your wiring diagram I don't see the 40 wires to both cell groups. I'm sure you don't mean it that way, but if you connect all 20 balance wires to just one cell group (commonly defined as one parallel row of cells), ...
by amberwolf
Jan 16 2022 11:45pm
Forum: Battery Technology
Topic: BMS parallel setup: 2 batteries 1 controller
Replies: 13
Views: 178

Re: BMS parallel setup: 2 batteries 1 controller

To prevent the above situations I noted, you'd need to do one or more of the following things: --Detect the voltage of each battery as it is connected, via a separate monitoring connection from the main Y-connection. Shut off the Y-connection to it. Compare the two readings. Re-enable the connection...
by amberwolf
Jan 16 2022 11:26pm
Forum: Battery Technology
Topic: BMS parallel setup: 2 batteries 1 controller
Replies: 13
Views: 178

Re: BMS parallel setup: 2 batteries 1 controller

the problem is that this would eventualy be a retail product and Im trying to develop a more user friendly system whereby the customer wouldnt be concern with needing both packs to be the same SoC Then you'll need to develop and produce the device that does what you want to happen. It isn't likely ...
by amberwolf
Jan 16 2022 11:12pm
Forum: Battery Technology
Topic: BMS parallel setup: 2 batteries 1 controller
Replies: 13
Views: 178

Re: BMS parallel setup: 2 batteries 1 controller

I have a bike with Kelly KBS 72v controller and a 20s8p battery. I want the option to add on another 20s8p battery in parrallel to add more capacity on some occasions. Each of the batteries would have its own BMS and I was thinking of adding a 3rd one to manage the two packs as I would imagine each...
by amberwolf
Jan 16 2022 8:51pm
Forum: Battery Technology
Topic: Need advice for Bafang battery
Replies: 7
Views: 130

Re: Need advice for Bafang battery

I'm thinking about getting a Bafang 1000W kit but not sure what battery is the best option. I don't know but I read in a review that for example the 52V battery is not worth the money. It's better to stick with the 48V. I would like to keep it in the <$300 range. Without knowing what "bafang 1...
by amberwolf
Jan 16 2022 8:33pm
Forum: Battery Technology
Topic: How important is matching li-ion cells in a largish pack made entirely of new batteries?
Replies: 21
Views: 545

Re: How important is matching li-ion cells in a largish pack made entirely of new batteries?

IIRC, lithium shipping regulations require something like max of 30% charge. So they should read fairly low in voltage; you can check the molicel charge curve for that model to see where your voltage falls on it.
by amberwolf
Jan 16 2022 8:31pm
Forum: EBike Technical
Topic: 52v 40Amp Battery From ebay
Replies: 3
Views: 104

Re: 52v 40Amp Battery From ebay

Hi all.. it’s been awhile. I wanted to get my ebike on the road again for summer and I need a battery. I come a cross one on ebay uk as I’m not good in battery cell and specs stuff I thought I get your views and thoughts about this first. https://www.ebay.co.uk/itm/234276277639?hash=item368bf44d87:...
by amberwolf
Jan 16 2022 3:38pm
Forum: EScooters/EMotorcycles
Topic: AE966600 Throttle error
Replies: 6
Views: 183

Re: AE966600 Throttle error

Is that while wheel is offground? Or while riding? If riding, under what specific conditions?

Is it using torque (current) throttle control mode? Or speed (voltage) mode?

If it's the first in both cases, then that's normal, and wouldn't do that while riding.