Buyin a battery pack

camerart

100 W
Joined
Mar 16, 2012
Messages
103
Location
England
Hi,

I fitted a 250 motor kit to my bike last year, and other things got in the way, which means I still haven't bought a battery yet.

First, I was going to make up a pack, then buy from china, but now I am wondering if it is best to by from here, in the Uk, for a guarantee, and no hidden charges while in the post.

I mainly want a brick shaped pack, 36v so I can go a 30 mile circular route, that for me would be a bit too far without help. e,g, 50/50 me/battery

I have read a lot about batteries, but the information keeps changing, so I need help to choose, please.

EDIT: Is this a good one?:http://www.greenbikekit.com/36v-15ah-li-ion-rear-rack-battery.html

Cheers, Camerart.
 
You can try to use a headway LiFePO4 battery pack with battery management system(BMS). Headway cell are well know and good quality cells if search on forum. Their quality beats most of other LFP cell.
 
I did a quick search, but they seem very expensive. The quality might be superior, but this is my first battery pack, so I really just want a tried and tested popular one.

Thanks for your suggestion though.

C.
 
Some of the reasons the info keeps changing is the quality of the cells used drivers weight and driving up hills and your riding speeds. When you buy already build bikes I really believe they over rate the mileage longer so it sounds good.

I have ordered from Greenbikekit delivery to UK a few times never had any problems (not a battery though). Make sure you choose First Class Parcel Force Tracked Delivery to be safe.

Personally someone who has that type of battery and is doing 50/50 battery and peddling can give you a more better answer. I have read 15Ah giving 30miles.I am running Lipo Packs and I get low mileage then others who claim twice as mine mileage may be I hardly peddle. I have had my Lipo battery’s over a year and a half and still strong.
 
We need more info on your controller as it controls things. Like how many amps it will demand from the battery. Plus do you have hills or just flat riding ?
It's best to buy a battery to match your controller, motor and terrain. Don't go to cheap or one that barely meet your needs working at its limits all the time.
 
Good job you asked me what controller I have, as I might have asked advice on the wrong voltage!

Controller SO6S 24V
250W 36v Hub motor
S-LCD1 E-BIKE METER 24/36V

EDIT: I am medium weight. I live in a fairly flat area, with a hill about 500Ft.

C.
 
eva-michael said:
You can try to use a headway LiFePO4 battery pack with battery management system(BMS). Headway cell are well know and good quality cells if search on forum. Their quality beats most of other LFP cell.
For batteries, I make the following recommendations, in my order of preference:
  • A123 AMP20 prismatic pouch or 26650 cylindrical cells from OSNPower (pouch kit or cells with welded tabs)
  • Headway 15ah or 12ah (screw-ends, so ready-to-make)
  • A pack made by cell_man at EM3ev (ready made)
  • A Ping pack (ready made)
  • 18650 format cells from Panasonic or Samsung, variously sourced (then spot-welded)
  • used Makita Konion cell packs from Doctorbass (scavenged cells, spot-welded)
camerart said:
I did a quick search, but they seem very expensive. The quality might be superior, but this is my first battery pack, so I really just want a tried and tested popular one.
A battery worth buying and using will cost - just no way around it for now until the cost of quality battery packs comes down. That will happen when Tesla finishes his gigawatt factory in Nevada.

Note that the least-costly battery pack will be one you make yourself from cells acquired from A123, Panasonic or Samsung. You're providing the labour and a good pack takes time. The A123 prismatic pouch cells from OSNPower can be had with their kit - which bolts tabs in place, so no welding required. The cylindrical cells need to be spot welded, and there are threads on the forum dealing with that. For ready made packs, one from EM3ev or Ping.

Or get
  • a battery pack from your local friendly electric bike shop - whatever they carry
  • a pack from the same vendor you bought your eBike kit from

Not listed for reason: RC Lipo cells made up into packs
 
Thanks Arkmundi,

A lot to think about there. I notice much of the info, is from other countries or making packs, this might be for future, I have experimented with spot welding, but for this pack I want to buy a ready made one. Hopefully a tried and tested one from a UK vendor if possible. Failing that I will spread a bit wider.

C
 
If I did buy from China, does this sound ok? https://bmsbattery.com/ebike-battery/622-high-c-rate-36v15ah-li-ion-alloy-07-case-battery-pack-battery.html

C
 
What I was asking was the amp draw of your controller. Lots of kits have a controller that was meant for use with old lead batteries. With a high demand from the controller. It's the controller that demands amps from the battery. You must buy a battery that matches your controller. That's why it's called a controller.
Bmsbattery can be a hit or miss company.
Ping, em3ev, ebike.ca,
But to truly recommend a battery we need to know about the controller and it would be good to know the bike you're going to be putting it in as if a battery could fill in the Triangle or on the rack or a so-called water bottle battery which is not actually the shape or the size of a water bottle. Don't get too small or too cheap a battery as you you will be buying a second battery very soon if you do.
Maybe you have a link to your kit as 250watt won't tell us much in reality.
 
Thanks 999zip999,

Here's a photo of my charger: It looks like the max current is 15Amp.

The kit will be fitted to an old mountain bike. (with a rack and panniers). I'm hoping to fit a square type battery pack on the rack. I also have a second project in mind for a later date, to be able to use this battery.

I enquired around some of the local bike shops, and it appears that none of them are interested in experimental bikes/batteries only the high end complete e-bikes.

C.
 
If you look in the, For sale new section ~ "Welding battery packs in Europe". Schwibsi is in Germany and makes quality packs with real cells. Or get a Ping 36v15ah or Paul at em3ev or Justin at ebikes.ca.
Get a battery from someone who cares.
 
Schwibsi says he will build a battery, but suggests, no BMS and doesn't normally add balance connections. Does this seem a good idea?

C.
 
If you don't have a BMS, and no balance connectors to be able to check cell groups later without opening up the pack, if you do have a problem at some point. If you're lucky, it'll never have a problem, but things do age and sometimes it's good to be able to check or even manually balance a pack.
 
A set of sense wires is a must for knowing voltage of parallel sets of cells. If no bms you need to build a bigger pack so you never drain pass 75% or so. Meaning you need to monitor your pack with a cycle analyst or watt meter. A first pack is best severe with a bms, I like the blinky lights of a signalab style bms and a set of sense wires for a cellog so I can still self monitor and I do like I'm married to it. I also had many used sonyy vts3 1500mah cell homemade packs they stayed in balance but needed monitoring up to 72v15ah. That's the law.
 
It seems best to have all the monitoring wires and circuits available, at least as the cells get older.

I assume that when Schwibsi suggested I don't use them with his home made pack, could be that he uses good quality cells, that stay balanced. As the sony cells 999 mentioned.

C.
 
Schwibsi likes the high quality Sony cells in his battery packs that stay in balance and people claim they share voltage for balance. Being a high c~rated cell is also a big advantage. That is the best thing about his packs. But I couldn't have a battery pack without sense wires. Meaning build parallel than series for ez sense wires or BMS or alarms or ? These is your first battery.
 
Hi 999,

I've been looking at batteries, cells, suppliers, manufacturers and prices all day. All the time bearing in mind that price mostly equals quality, but not always.

I'm now looking at model batteries multiplied up to the correct voltage/current, they all have balance connections, which are versatile and I've got experience of them too.

EDIT: BMS understood.

C.
 
Hi,

I've been overdosed with too much information, and I've run out of free time for looking.

I've just ordered 10X Turnigy 5000mAh 3S 35C Lipo Pack. I've used similar with models, so they should do the trick. They add up to just over £200, as opposed to up to £350ish for alternatives, time will tell whether I've chosen well. I'm going to join at least 9X of them together to make my 36V 15Ah battery. Later, after playing with this set, I'll look again, with more experience. I just couldn't wait any longer :)

Thanks, for all the help.

C.
 
Still you have to cycle,test and balance before assembly. Just write on the packs.
Getting married to lipo. She's a lot in a bottle.
Lot's of good lipo build threads. But I use heavy big lifepo4. Long lasting, safe A123. Heavy.
 
Yes, I'll watch the cell balancing. Also the danger of fire.

Looking forward to testing them on the bike.

C.
 
I would have a pack made from schwibsi 10s and have him put a 40a bms and bulk charge plus have a gasket on the pos. terminal of each cell. Then buy a second 10s for 20s for your next bike. The reason is he uses quality cells so better chance of a longer lasting pack.
Remember it is us forgetting to charge a pack or Crossing wires. Or drawing to many amps on a cheap cell battery. That kills them.
 
Thanks 999,

Too late! About 4x posts back I said that I've ordered 10x 5000mA batteries from Hobbyking. I'll be able to use them for models as well. This will be my first pack, and I'll be able to get the feel of this exiting hobby.

C.
 
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