how far with 12ah headways ?????

[crimsonsnake0]

hi i have just travelled 19 miles with my ebike. 12ah headway batts. is that good average or what ? still had 55.4 volts left unloaded. my set up is actually 17 headway batts rather than 16 so starting volts is 60. dont use bms at all and never had 1 over charge. how far have you all travelled regards.

 

[jimw1960]

with a 16s setup, I count on 2 miles per amp hour with a 25 amp controller. At higher speeds with a bigger current draw, that rate would drop.

 

[crimsonsnake0]

so i could possibly get 25 miles if i go easy with throttle ? thanks for that

 

[jimw1960]

one thing to consider since you do not use a BMS or balance charger, the lower you draw the cells down, the more potential for the cells to get out of balance. So, limiting to 20 miles or so when possible would keep that extra reserve so that the weaker cells are not stressed.

 

[julesa]

so i could possibly get 25 miles if i go easy with throttle ? thanks for that

I get about 1.5 miles per amp-hour @48V riding normally (normal for me, that is). 2 miles per amp-hour is my best record, riding slowly and conservatively, pedaling a lot. But I have a lot of hills in my area and a 30A limit on my controller, so you'll probably do better.

My wife's ride has a 25A limit, a flatter commute, and she likes a slower pace. Riding conservatively she gets about 3 miles/Ah, and normal riding about 2 miles/Ah @48V.

Both of us are using 9C 9x7 hub motors.

 

[999zip999]

Hay Snake, What motor and controller (amps) ?

 

[neptronix]

What you need is a cycle analyst or turnigy watt meter.
Everything else is theoretical and fuzzy.

Ebike miles are variable just like city and highway miles are on a car. Hill miles are even more variable than that.

Run it 'till it's dry with an amp metering device and you will know how many miles you can go.

 

[torqueon]

17 miles on a 20 amp 36 volt system. Me + bike 215 Lbs. Average speed 20 M P H . Terrain is hilly and lots of wind lately
As said many variables to account for, need instrumentation to really know! However glad to find this thread to compare with.

It seems like my performance has gotten better after a few charge cycles. Do you all find the same

 

[neptronix]

Also you go faster on more volts.
So it's all about watts, not just amp hours

 

[torqueon]

Also you go faster on more volts.
So it's all about watts, not just amp hours

Need to get a wattmeter as suggested. Hard to crunch numbers while staring at a volt and amp meter while riding L O L , that's worst than texting and riding.

 

[neptronix]

Yeah lol

Actually i have a wattmeter and i look down at it from time to time.. hmm.. maybe i should stop doing that and carry more AH so i don't have range anxiety..

 

[julesa]

Headway cells have a lot of variability in how fast they self-discharge; at least, mine have. Some cells will self-discharge faster than others. Your pack might go out of balance faster than some other people who have had good luck going without a BMS. With Headways, if you're bulk charging without monitoring individual cell voltage, it's pretty easy to seriously overcharge the strongest cells in your pack. One solution is to use cheap little RC pack monitors. At least check individual cells with a voltmeter at the end of your charge, to make sure things are working how you expect. You can probably get away with watching a pack level wattmeter on discharge for a while, and just watch for an accelerating drop in pack voltage. I wouldn't trust myself to do that, though. Sooner or later one cell would drop out faster than I expected, and I'd miss it. I need an LVC or at least an alarm of some kind.

 

[torqueon]

Yeah lol

Actually i have a wattmeter and i look down at it from time to time.. hmm.. maybe i should stop doing that and carry more AH so i don't have range anxiety..

Funny I have the range I need, but since this is electric and new to me, I am compelled to push all the limits !! The batteries, motor, drive train etc. Have read many race threads ! L O L
I am off to paint my armature black got to get ride of that Heat somehow ? Summers coming

 

[neptronix]

Headway cells have a lot of variability in how fast they self-discharge; at least, mine have. Some cells will self-discharge faster than others. Your pack might go out of balance faster than some other people who have had good luck going without a BMS. With Headways, if you're bulk charging without monitoring individual cell voltage, it's pretty easy to seriously overcharge the strongest cells in your pack. ..... Sooner or later one cell would drop out faster than I expected, and I'd miss it. I need an LVC or at least an alarm of some kind.

Sounds like these are variable just like lipo are, maybe more so.
I think the thing with headways is that they are not the highest quality cell. There will be natural variation.
I think if you run those without a BMS, then you should treat them like HK lipo should be treated; leave 10% of spare capacity at the bottom, and 5% of spare capacity at the top.

The fact is that some cells just charge quicker and discharge quicker than others. You can balance them as much as you want but they will always act that way. As you wear them funny with a BMS over a long period of time, it is that cell that will die a premature death.

 

[dnmun]

i disagree. i think the headway screw top is a first class cell. not sure what results others have had, but i have seen no more than a total range of 3% in capacity. but i can't do accurate capacity measurements either. i bet it is really better than that.

out of about 154 headway blue sleeve cells, both screw top and the older type L tabbed, i have only had 4 bad cells. 2 were tab cells soldered on the negative end. the other two were screw tops that were used in a booster pack without a BMS.

i think this was the turning point for headway too, they make good cells. seems like you can kill them by over discharging them, which they will do easily on max amp. without a BMS.

 

[julesa]

Headway cells are great. There's not really any variability in how fast they charge or discharge while in use. What I was saying is that over a period of weeks, even just sitting on a shelf, some of them will lose their charge a little faster than others, and if you're not balancing them regularly it won't take long to get a few cells that are noticeably out of sync with the others in your pack. Since they *will* get out of sync eventually, it's really easy to overcharge some cells if you're not watching voltage on individual cell groups when bulk charging. That's all I meant to say.

 

[dnmun]

no problem, i was just commenting on what dave said. i now can add one more dead headway. overcharged it last night until this morning, while on a 5V cell phone charger. 0V. baked it on a 800mA wallwart.