Headway batteries advice

[Tommy L]

Thank you Jimmie for running these tests and posting the results!

Although they can handle sustained 10C, the voltage is low.

This is why I build the Headway packs with 2C max in mind if I want to maintain a certain
voltage. They don't sag at 2C. I find they work great. The main complaint is most see
the HOC at 3.65 or 3.7v per cell, then they load it and see it go to 3 or 3.2v per cell
and call it sag. They will stay at the 3.1 or 3.2v per cell under a 2-4C load until
100% capacity is used. On my test, I've noted that they go a little beyond the
rated capacity before that 3.2v falls off a cliff.

If we build packs to keep the stress off the cells, both you and the pack will be happy :wink:

Tommy L sends....

 

[999zip999]

I agree don't over tax your battery.

 

[JimmieD]

Thank you Jimmie for running these tests and posting the results!

You're welcome!

This is why I build the Headway packs with 2C max in mind if I want to maintain a certain
voltage. They don't sag at 2C. I find they work great. The main complaint is most see
the HOC at 3.65 or 3.7v per cell, then they load it and see it go to 3 or 3.2v per cell
and call it sag. They will stay at the 3.1 or 3.2v per cell under a 2-4C load until
100% capacity is used. On my test, I've noted that they go a little beyond the
rated capacity before that 3.2v falls off a cliff.

If we build packs to keep the stress off the cells, both you and the pack will be happy :wink:

Word! 8)

I agree don't over tax your battery.

Words of wisdom! Design the battery with a 2~3C discharge rate, and only if necessary, then it can handle the 10C rating if actually needed. Sorta like a stock Pinto and a stock Porsche, both will get you there, but one can provide the power when and if you need it.

 

[hillyterrain]

Just ordered 14 15Ah cells from headway hq, let's see how service, delivery and the quality of the cells hold up I'm planning to use the 15Ah cells with 20A continuous, once I get a new controller with 30A continuous ..

 

[Tommy L]

Just ordered 14 15Ah cells from headway hq, let's see how service, delivery and the quality of the cells hold up I'm planning to use the 15Ah cells with 20A continuous, once I get a new controller with 30A continuous ..

I'm sure that you will report back here your findings. 30A continuous is 2C. You should be fine.
Are you going for 12S with two spares?

I'm just building a 38120HP in a 4s2P 12v 16ah for my friend. It's for his son's plastic Electric truck
The Lead battery use to last 30 to 40 minutes. It now lasts for 5 lol. I took them over a test pack.
They love it! The lead was 7 amphrs and now they have a true 16amphrs . On the GPS, 5kph with the lead.
7kph with the 38120hp

I use the same configuration in my and my friends motorcycles. 4s2p. with bleed resistors to protect
from over charging. By accident, I left my motorcycle ignition on and the high beam was also on for 2.5hrs.
She started right up! Got love having a true 16ah battery. Also, it's always sitting above 13v, so it turns the motor faster :wink:

Tommy L sends.....

 

[dnmun]

Just ordered 14 15Ah cells from headway hq, let's see how service, delivery and the quality of the cells hold up I'm planning to use the 15Ah cells with 20A continuous, once I get a new controller with 30A continuous ..

why would you only order 14 cells? you need 16 for the 48V BMS. you should see if he can add the extra 2 cells to your order.

 

[hillyterrain]

I don't have a BMS and my RC charger can only balance 14 cells.. Am I missing something here or should that work just fine?

 

[dnmun]

if you don't have a BMS then you don't have short circuit protection or protection from over discharge. it is much cheaper to just use a BMS and bulk charger and it charges much much faster.

 

[Tommy L]

I don't have a BMS and my RC charger can only balance 14 cells.. Am I missing something here or should that work just fine?

I haven't used a bms yet (I've got one coming, should be here soon). I've been doing this for two years now, but really.....GET A BMS.

jimmieD has the whole kit. Spend more time riding, and less time fiddling around.
But learn how to keep an eye on all the cells, in the case of a bad BMS or bad Cells.
Know your gear! :wink:

With the BMS, if you have a bad cell, the Low Voltage Cut(LVC), from the BMS will shut the pack down.
When you notice that you can't pull a reasonable amount of Watt Hours from the pack because the BMS is
shutting down the pack (low LVC on a cell) you know something is wrong. Fault find, fix issue, continue riding

I use Alarms on my balance leads. This notify's me immediately if a cell drops below my set point.

Tommy L sends.....

http://headway-headquarters.com/diy-48v-15ah-headway-battery-kit/

 

[hillyterrain]

Don't alarms drain the cells unevenly? I like the idea of a BMS but I already spent money on the hyperion so I'm thinking on saving some now.. Shouldn't be that much fiddling, just plug in a second plug with all the balance leads for charging.. How much real voltage will 14s give me?

 

[Tommy L]

Don't alarms drain the cells unevenly? I like the idea of a BMS but I already spent money on the hyperion so I'm thinking on saving some now.. Shouldn't be that much fiddling, just plug in a second plug with all the balance leads for charging.. How much real voltage will 14s give me?

3 to 3.2v per cell under load for the capacity of your pack. So 14s around 42 to 45volts.

Tommy L sends....

 

[hillyterrain]

I have an in line fuse against shorts and monitor the cells individually with cell logs (I think 14 cells are good for 2 logs) I have a cycle analyst for level pack shutoff...

If I didn't have already the hyperion and meanwell I'd get a BMS, but I'm trying to be cheap... Maybe too cheap? I also heard of people having trouble caused by BMS, so I thought keeping it simple would be nice

 

[hillyterrain]

I think that should be fine, the cadence of the gng is way too high anyways.. That'll slow it down a little.. Running it on 46V according to CA right now (LiPo) and my feet are spinning without resistance..

 

[Tommy L]

Don't alarms drain the cells unevenly? I like the idea of a BMS but I already spent money on the hyperion so I'm thinking on saving some now.. Shouldn't be that much fiddling, just plug in a second plug with all the balance leads for charging.. How much real voltage will 14s give me?

Yes alarms will do that, but not at a huge amount. You just don't want to leave them plugged in all day and over night
or all week. To use them while you are riding may not be a bad thing. They drain the cells that is powering the alarm.
I believe someone mentioned that on a 6s pack, a 6s alarm will draw from #1 and #2 cells out of the 6.

I'm a builder/fixer/tinkerer ect.... I don't mind babysitting and learning about my gear. Now that I fully understand my gear, I'm reading for
a BMS

Tommy L sends.....

 

[hillyterrain]

Same here, I'm sure the BMS will come one day..

 

[dnmun]

but with 14S you are giving up 15% of your top speed.

you have no short circuit protection and i guarantee it will get over discharged unless you monitor each channel with cellogs and then it could drain down on the controller while you are sleeping too.

 

[hillyterrain]

I guess I could run 60V and have even more topspeed, the question is how much top speed I need.. The20A fuse should handle shorts? Yes the cell logs need to be unplugged, they can be hacked to drain evenly and have an alarm output signal to shut down the controller..

I agree a BMS is nice, will probably get one soon, but want to try how it is without one..

 

[dnmun]

it seems like all the newbies think they should build a pack and not use a BMS. they even started a thread last year promoting the idea that it is best to not use a BMS. or that it is too expensive, or that it uses current to function, or that it prevents power from reaching the motor. all imaginary problems from people who never understood how a BMS worked so they just made the blanket assumption they are not needed if they don't understand how they work.

this one is $29: http://www.bestekpower.com/512v16spcmbmspcbforlifepo4batterypack/PCB-D132.html

and they have a bunch more: http://www.bestekpower.com/512v16spcmbmspcbforlifepo4batterypack/

 

[hillyterrain]

Thanks for the tip, excuse the newbie questions, where do I actually buy one?

 

[dnmun]

you can contact henry at bestekpower using his email: henry@bestechpower.com

i just bot 5 BMSs from him for $193 including shipping. for one thing the shipping is gonna be about $15 i expect. it cost me $20 for 5.

 

[e-beach]

After careful consideration I have decided to get Headways 12S 15AH for my wifes new pack. I have checked the prices from both the Chinese and American companies and I believe I will spend a bit more and buy American. Headway Headquarters and Manzanta Micro were the choices but I know very little about either company. .......

So who did you end up ordering from?

 

[hillyterrain]

dnmun: If you do a bulk order of BMS in the future, I might be in ..

 

[eganwp]

Doc,

I know we chatted about this before. Nice to see you're also going headway route.

I'm just waiting arrival of my 72V 15Ah headway cells, BMS, charger, wiring and all plastic holders and bridges as one huge kit from battery-matrix.com. They custom built me a 50A BMS for free for it. can't wait to get this wired up on my new Cellman 14FET and cellman 5A 86.8V charger. bike is gonna haul!

Took a lot of careful consideration (aka months) to finally decide to drop all that dough at battery-matrix. By far the cheapest place with free shipping on the entire order and includes a descent BMS and free 86.8V charger, all wiring, taps, connectors, custom plugs, plastic cell casings, brand new tested headway 40152 15Ah cells, etc.

I don't know of anyone on this forum who has bought from them so I decided to be the guinea pig and also told them I'll be posting a full review of their kit for them as well if time permits.

Travis

 

[docnjoj]

Thanks for the info, Travis. I looked them up and the only problem I see is there are only half the number of plastic blocks needed to make a 12S battery. They need to be used at both ends of the cell and they only give 12? Thanks
otherDoc

 

[dnmun]

no such thing as a custom BMS or free charger. they needed to adjust the charger voltage up to 89V so it will balance. they should know that if they sell batteries.