Battery DIY.

[soundwave]

2002-2017

 

[1boris]

I need a cheap bms for this battery,the motor controller is 25a :

http://www.ebay.com/itm/Ebike-Pedelec-Akku-17400mAh-36V-LiNiMnCoO2-NCR18650PF-Li-Ion-10S6P-/192058882946?hash=item2cb799fb82:g:zQgAAOSw5cNYWlm1

Anyone have a link to one I can use ?

 

[Renax]

What I said is, "so maybe 1Ah of useable battery", which is confirmed by the graph. The 20A line crosses the 3.1v cut-off at 1.125Ah. That's under ideal lab conditions and it's one cell. When you have 13, they'd all have to be perfectly balanced to get that, which is never going to happen. In fact, I've changed my mind now. I'd say that you'll be lucky to get 1 amp hour out of it.
The motor will be pulling the maximum 20A nearly all the time, which means 3 minutes use!

Well, 1. you read the graph wrong, its the 25A line that crosses there, the 20A line goes to 1750mah

2. Why will they be so badly balanced? (I don't know, I have never used more than 4 18650 together, they stay pretty much perfectly balanced..

3. It will? do you have anything to support your claims? (genuinely curious, as I said before, this I don't know, but I intend to find out.

Recumbent, no throttle bbs01 set to 15a and fully legal.
It runs at 16-20 mph on the flat. So no battery use normally,only up hill.

Relevant info, thanx

@soundwave : heres relevant testing, pulsing done up to 70A for 5seconds, aswell as continous testing up to 45A. And yes, those are the pritty pink batteries I use for extreme purposes, no, they do not last long between charges, but for my use they last about 300 charging cycles, which is decent for the application.

https://www.e-cigarette-forum.com/forum/threads/lg-hb6-pink-30a-1500mah-18650-bench-test-results-great-32a-1500mah-battery-better-than-ivory-hb6.736131/

 

[soundwave]

https://bmsbattery.com/search?controller=search&orderby=position&orderway=desc&search_query=bms&submit_search=

http://www.bga-reworking.co.uk/insat-li-nmc-ebike-battery-10ah-24v-36v-48v.html

 

[Renax]

I need a cheap bms for this battery,the motor controller is 25a :

http://www.ebay.com/itm/Ebike-Pedelec-Akku-17400mAh-36V-LiNiMnCoO2-NCR18650PF-Li-Ion-10S6P-/192058882946?hash=item2cb799fb82:g:zQgAAOSw5cNYWlm1

Anyone have a link to one I can use ?

I'll leave you a link to a test of those cells, about 2200mah @5A with 3.1V cutoff, pretty good for the price if you ask me. as for bms, a cheap one is easy to find, the hard part is finding a cheap good one..
https://www.e-cigarette-forum.com/forum/threads/panasonic-ncr18650pf-10a-2680mah-18650-bench-retest-results-an-ok-low-capacity-10a-battery.774091/

 

[soundwave]

http://www.pedelecs.co.uk/forum/threads/the-new-best-headlight.25228/

i use Panasonic 3400 mah cells for my lights and the faster i draw currant from them the less mah i get and is the same for a bike motor.

at 5 amps ill be lucky to get 1 hr on full beam with a 4s pack and 12v lights

 

[1boris]

https://bmsbattery.com/search?controller=search&orderby=position&orderway=desc&search_query=bms&submit_search=

http://www.bga-reworking.co.uk/insat-li-nmc-ebike-battery-10ah-24v-36v-48v.html

Thanks for the link,but I didn find a bms for LiNiMnCoO2,Dont know much about batteries so I need a direct link

 

[soundwave]

the capacity is based on a discharge rate of 1 amp and get 3400 on all the new cells i buy if i up the amps then it will not last as long as it is in series i have the voltage no capacity

 

[soundwave]

Thanks for the link,but I didn find a bms for LiNiMnCoO2,Dont know much about batteries so I need a direct link

email bga they can build the batt for you to your specs if wanted

 

[Renax]

the capacity is based on a discharge rate of 1 amp and get 3400 on all the new cells i buy if i up the amps then it will not last as long as it is in series i have the voltage no capacity

True, if you run them down to 2.5V, In 1boris's setup with a 10s6p setup @25A they'll run closer to 5A and probably cutoff closer to 3V?

 

[soundwave]

you dont run them down to 2.5v you want to cut them off at 3.5v as over that they fall off a cliff voltage wise anyway.

maxing out cells just destroys them and you will lose capacity fast and it is the same fast charging them as well.

get a sky rc mini charger and test some cells ur self

 

[soundwave]

 

[Renax]

you dont run them down to 2.5v you want to cut them off at 3.5v as over that they fall off a cliff voltage wise anyway.

Yea, You posted a specsheet and stated that @1A you get 3400mah, I looked at you specsheet and discovered you only get 3400mah if you run them down to 2.5v, if you do cutoff at 3v you get almost 3000mah.

Why you want to cutoff at 3.5v is unknown to me, Bafang does cutoff at 3.15v per cell... based on the test I've seen and my own experience thats a bit on the safe side, 3-3.1V should be fine depending on the cells in question..

 

[anotherkiwi]

One word: sag.

If you try pulling 15+ Amps continuous from a slightly tired 10.4 Ah 36 V battery over a 3.4 km climb by the time you reach the top voltage sag will be between 4 and 6 V... Your controller will cut out because the voltage will be below 3.1 V per cell. This is real world experience.

When you get to the top the battery will bounce right back up to over 36 V.

Your need was the one I had and so I read a lot and went over to the dark side of the force: LiPo = cheap battery, big Amps.

 

[danielrlee]

2002-2017

That Volcano is a fantastic bit of kit and worth every penny IMO! Tried my mates and did a henry in a massive black bin liner. I don't think anyone said a word for the next three hours. Happy times!

 

[Deleted member 4366]

I need a cheap bms for this battery,the motor controller is 25a :

http://www.ebay.com/itm/Ebike-Pedelec-Akku-17400mAh-36V-LiNiMnCoO2-NCR18650PF-Li-Ion-10S6P-/192058882946?hash=item2cb799fb82:g:zQgAAOSw5cNYWlm1

Anyone have a link to one I can use ?

Loads on Aliexpress. Think about a 40A one to leave a bit of headroom. You definitely need more than 25 amps.

 

[1boris]

Loads on Aliexpress. Think about a 40A one to leave a bit of headroom. You definitely need more than 25 amps.

Any thoughts about these batteries:

https://www.aliexpress.com/item/36v-20ah-lithium-ion-battery-42v-800w-Electric-bicycle-Scooter-power-AKKU-Batterie/32753903020.html?spm=2114.10010108.1000014.6.ELi8ty&scm=1007.13338.70306.000000000000000&pvid=dec38291-9053-41fc-bb43-4cbf89f93377&tpp=1

https://www.aliexpress.com/item/36v-lithium-battery-electric-bike-lithium-battery-36V-20AH-1000W-Samsung-cells-Electric-Bicycle-Battery-with/32737128777.html?spm=2114.01010208.3.98.Zcy57j&ws_ab_test=searchweb0_0,searchweb201602_5_10065_10068_10000009_10084_10083_10080_10082_10081_10060_10062_10056_10055_10054_10059_10099_10078_10079_426_10103_10073_10102_10096_10052_10053_10050_10107_10051_10106,searchweb201603_9,afswitch_5,single_sort_0_price_asc&btsid=90d4fa54-faa9-42ce-8904-67d51d78ddbf

http://www.pswpower.com/peng/iview.asp?KeyID=dtpic-2016-B2-BTBT.63VTM

 

[Deleted member 4366]

They're all very heavy because they have old-spec low capacity cells. My preference would be to pay more for a modern light-weight one, like you can get from Eclipse:

http://eclipsebikes.com/whale-174ah-lithium-frame-battery-samsung-cells-p-1128.html?osCsid=e53ed83456efa5724da31361733bdba8

Another thing: if you're going to buy a controller and battery, it might be worth going up to 48v for more speed and power. You don't need as many Ahs at 48v because you'll be using lower current most of the time. It's watt-hours that gives you range. Perhaps not 48v if you have a lot of steep climbs to do.

 

[1boris]

They're all very heavy because they have old-spec low capacity cells. My preference would be to pay more for a modern light-weight one, like you can get from Eclipse:

http://eclipsebikes.com/whale-174ah-lithium-frame-battery-samsung-cells-p-1128.html?osCsid=e53ed83456efa5724da31361733bdba8

Another thing: if you're going to buy a controller and battery, it might be worth going up to 48v for more speed and power. You don't need as many Ahs at 48v because you'll be using lower current most of the time. It's watt-hours that gives you range. Perhaps not 48v if you have a lot of steep climbs to do.

Ok,then I think I will go for this small lightweigt battery 36v 17,4 ah 2830kg,and find a bms for LiNiMnCoO2.

http://www.ebay.com/itm/Ebike-Pedelec-Akku-17400mAh-36V-LiNiMnCoO2-NCR18650PF-Li-Ion-10S6P-/192058882946?hash=item2cb799fb82:g:zQgAAOSw5cNYWlm1

The battery is for my bafang bbs02 250w 25a,the controller is for the Neo Cross.

 

[Renax]

Your need was the one I had and so I read a lot and went over to the dark side of the force: LiPo = cheap battery, big Amps.

Yea, that would probably be a better choise for my needs, but how are they regarding to shelf life? I'm probably not gonna use my bike every week, so shelflife is more important than recharge cycles. Link to a good cheap one which will give me 10-15min of full throttle on my 500w motor?