Search found 2634 matches

by SamTexas
Aug 04 2013 2:35pm
Forum: Battery Technology
Topic: Nissan Leaf Cells Test Data
Replies: 382
Views: 64739

Re: Nissan Leaf Cells Test Data

Yep, unfortunately these chargers were never designed for 1S. No need to redo the full test. Here a quick test to determine the voltage drop across those two short lead wires at 20A: Briefly rerun this 20A test, no need to start from a full charge cell. Use a voltmeter to measure the voltage at the ...
by SamTexas
Aug 04 2013 1:44pm
Forum: Battery Technology
Topic: Nissan Leaf Cells Test Data
Replies: 382
Views: 64739

Re: Nissan Leaf Cells Test Data

icecube: I looked again at your CAM00556 picture. Unless I'm mistaken, you did not have the sense wires attached. So your discharge graph was not showing the true cell voltage. Instead it was showing the cell voltage minus the voltage drop across the main leads. This might explain why the sag was so...
by SamTexas
Aug 04 2013 1:05pm
Forum: Battery Technology
Topic: Nissan Leaf Cells Test Data
Replies: 382
Views: 64739

Re: Nissan Leaf Cells Test Data

What I see is a battery from a Nissan Leaf, a relatively new car in the market. Well , actually what you see is a USED battery from a Nissan Leaf..... that has been used for many 100's of its cycle life expectancy. Which is why you would not expect it to still have its original Ahr capacity. I am a...
by SamTexas
Aug 03 2013 11:26pm
Forum: Battery Technology
Topic: Cycling lipo: how to check if they are good?
Replies: 24
Views: 537

Re: Cycling lipo: how to check if they are good?

And it's not a 0.5V difference. It's 0.05V.
cwah wrote: 0.5V difference.. it might indicate it's a weak cell. Or maybe it's because it's a new pack and cells are still opening...?
by SamTexas
Aug 03 2013 10:25pm
Forum: E-Bike General Discussion
Topic: Hobby or Money Saver?
Replies: 44
Views: 1846

Re: Hobby or Money Saver?

Hobby and Money Burner for me. But I'm not complaining.
by SamTexas
Aug 03 2013 7:27pm
Forum: E-Bike General Discussion
Topic: hypothetical range question..
Replies: 89
Views: 2328

Re: hypothetical range question..

swbluto wrote: The difference is a 40psi knobby compared to a 100psi ultra-low-rolling resistance primo tire.
Ah. That's not a fair comparison, but I see what you mean now. I thought you were comparing it to a street tire.

Going from a 40psi knobby to a 65psi street can easily give you 10 watts difference.
by SamTexas
Aug 03 2013 7:22pm
Forum: Battery Technology
Topic: Nissan Leaf Cells Test Data
Replies: 382
Views: 64739

Re: Nissan Leaf Cells Test Data

I am looking for house batteries. A 12V system for now. Probably go to 24V later on. These cells are figuring 3.8V per cell, correct ? That makes 4 cells @ 15.2V nominal ?? A bit too high for a 12V system, If I hook up 2 sets of cells @ 4s4p ? 3 cells make it 11.4V nominal ? That's too low. .... An...
by SamTexas
Aug 03 2013 7:14pm
Forum: E-Bike General Discussion
Topic: hypothetical range question..
Replies: 89
Views: 2328

Re: hypothetical range question..

swbluto wrote: I also installed a new primo low-rolling resistance tire on the back which reduced the average power consumption by 20-30 watts...
That sounds too optimistic. I don't believe it until I see the actual test data. I would be extremely happy if a low-rolling tire gives me a 10 watts saving.
by SamTexas
Aug 03 2013 6:44pm
Forum: E-Bike General Discussion
Topic: hypothetical range question..
Replies: 89
Views: 2328

Re: hypothetical range question..

I got my recumbent for $400 on ebay, rear-suspension to boot, and can bike upto 200 miles on 1000wh. What was your overall moving average speed? I have a 1.4Kwh (exact capacity from 4.2 to 3.0V per cell) battery on my mountain bike (with street tires). I can do 140 miles at an overall moving averag...
by SamTexas
Aug 03 2013 5:45pm
Forum: E-Bike General Discussion
Topic: hypothetical range question..
Replies: 89
Views: 2328

Re: hypothetical range question..

It never hurts to ask specific questions, one at a time. But don't forget to also ask for on-topic, relevant answer to the question.
by SamTexas
Aug 03 2013 1:39pm
Forum: E-Bike General Discussion
Topic: hypothetical range question..
Replies: 89
Views: 2328

Re: hypothetical range question..

When I say 500Whr I mean 500Whr usable energy. For me that's exactly 500Whr until MY LVC is reached. And my recommendation was very specific for this young OP who said he could do 20kph for at least 2 hours. I'm not giving the advice to an old geezer who can't barely produce 100W for half an hour, o...
by SamTexas
Aug 03 2013 11:38am
Forum: E-Bike General Discussion
Topic: hypothetical range question..
Replies: 89
Views: 2328

Re: hypothetical range question..

One of my riding partners (regular bicycle) is 63 years old. We usually complete 36 miles (58 km) in 160 minutes (2hrs 40mins). If we were to it on an ebike and using the same effort we would complete it in 120 minutes and consume around 9Wh/mile. Of course, we could also easily complete those 36 mi...
by SamTexas
Aug 03 2013 8:38am
Forum: E-Bike General Discussion
Topic: hypothetical range question..
Replies: 89
Views: 2328

Re: hypothetical range question..

muffinman wrote:... im fairly confident i could maintain at least 20kph on my own for at least a couple hours.
Good. You only need a 500Whr battery to do 90km at 30kph average.
by SamTexas
Aug 03 2013 7:45am
Forum: E-Bike General Discussion
Topic: hypothetical range question..
Replies: 89
Views: 2328

Re: hypothetical range question..

ok, the real senario: my girlfriend lives about 90km away during the summer. If you are willing to pedal lightly and don't mind a 3 hours trip, it can easily be done. Not too expensive either. No more than 300W is needed to move at 30kph on flat ground. If you pedal along and contribute half the po...
by SamTexas
Aug 02 2013 9:26pm
Forum: General Discussion
Topic: delete all board cookies ?
Replies: 61
Views: 5503

Re: delete all board cookies ?

I wonder how too. I'm getting worried. Is it possible that ES is one of the bad sites that snoops around for IP addresses. Isn't that illegal?

So glad you're investigating this. I hope you'll get to the bottom of this and share with everyone. Thanks for your effort.
by SamTexas
Aug 02 2013 3:48pm
Forum: E-Scooter and Motorcycle Photos & Videos
Topic: my home built runaround
Replies: 49
Views: 10442

Re: my home built runaround

Thanks. It's nice to see an elegant, powerful build. The lack of pedals made it an "honest" vehicle. I like the CA's display of 155Wh/mile.

I got sick of looking at powerful, ghetto looking electric bicycles with show only pedals.
by SamTexas
Aug 02 2013 12:55pm
Forum: General Discussion
Topic: Daily Transportation survey
Replies: 10
Views: 874

Re: Daily Transportation survey

Done. Looking forward to see the interpretations of your polls result.
by SamTexas
Aug 01 2013 8:00pm
Forum: General Discussion
Topic: delete all board cookies ?
Replies: 61
Views: 5503

Re: delete all board cookies ?

That's what I heard. It's a complicate scheme. The FBI usually have a team of experts working on case like this and it takes months before they gather sufficient evidence. It's definitely not a job for a lone hacker. You might want to get in touch with the proper authority.
by SamTexas
Aug 01 2013 7:45pm
Forum: General Discussion
Topic: delete all board cookies ?
Replies: 61
Views: 5503

Re: delete all board cookies ?

Does E.S. sell this info collected from members computers ? Yes. The question is how many pennies they can earn from doing it. The last I heard is 3 pennies per year per member with more than 10,000 posts, and 1 penny from the rest. Why hasn't anyone brought this illegal practice up is a mystery to...
by SamTexas
Aug 01 2013 3:02pm
Forum: E-Bike Technical
Topic: Using cell monitor/balancer with LiPO
Replies: 13
Views: 502

Re: Using cell monitor/balancer with LiPO

Correct. But the required power is not the main concern. Most of these devices draw very little power. The concern is they don't draw power equally from all cells in the pack, thereby creating a perpetual imbalance. Ex: A 37V LiCo pack with a capacity of 20Ah. That's ten 20Ah cells in series. A cell...
by SamTexas
Aug 01 2013 12:37pm
Forum: E-Bike Non-hub Motor Drives
Topic: New Bosch Motor.
Replies: 118
Views: 9517

Re: New Bosch Motor.

Is the U.S market nearly as huge as here though ? considering the E.U population being much larger ? I think it has very little to do with population and a lot to do with penetration percentage. If Europe has a 10% population penetration rate (1 out of 10 will buy an ebike), then the USA rate is pr...
by SamTexas
Aug 01 2013 12:02pm
Forum: E-Bike Technical
Topic: Using cell monitor/balancer with LiPO
Replies: 13
Views: 502

Re: Using cell monitor/balancer with LiPO

Not a good idea for many reasons: 1) 50mA balancing current: The balancing current is too small to handle the normal charging current. So when cells get out of balance, this balancer can only slow down the imbalance rate, but cannot stop it. Eventually one or more cells will be overcharged. This bal...
by SamTexas
Jul 31 2013 7:01pm
Forum: Battery Technology
Topic: Nissan Leaf Cells Test Data
Replies: 382
Views: 64739

Re: Nissan Leaf Cells Test Data

I'm no expert but isn't the voltage constantly going down? I don't think that's very beneficial, I'm used to see the voltage coming down fast at the beginning to a certain point then hit a plateau for some time until it drops down at the very end of the discharge. Only LiFePO4 has the characteristi...
by SamTexas
Jul 31 2013 5:27pm
Forum: Battery Technology
Topic: Nissan Leaf Cells Test Data
Replies: 382
Views: 64739

Re: Nissan Leaf Cells Test Data

mvly wrote: Lets do the math:...
Well, none of the values used in your math is real. So the result is not meaningful.

What I see is a battery from a Nissan Leaf, a relatively new car in the market.