About to buy BBS02 750w kit

[tony2311]

How do i tell if it is the 6 fet or 9 fet version ?

 

[Fordulike]

Ask the supplier for the date of manufacture or at least the manufacturing code, which is marked on the bottom of the unit:


First two numbers are the year of manufacture and the next two are the month. This one was made in July 2013.

I don't know when they permanently swapped over to the 9 fet controllers, but anything manufactured this year, will at least guarantee you get a 9 fet

 

[trex]

I think all the 25A motors have 9 FETs, the rest have 6 FETs

 

[Fordulike]

I think all the 25A motors have 9 FETs, the rest have 6 FETs

I'm not entirely sure that's true trex. This is an excerpt from em3ev's website, which suggests that they did have a 25A 6 fet at one stage:

"News - 11th Apr. 2014

The 750W BBS02 kits are temporarily out of stock. We are arranging some new stock and expect to have the 48V 500W and some other new models by around 24th April. The 48V 750W and 36V 500W BBS02 production has temporarily stopped whilst a new version 25A controller is finalised. If truth be told, the controller on the 25A controller on the 48V 750W kits was a little under specced (for a 25A controller) and in standard form would actually typically pull almost 30A max from the battery. Bafang are now moving to a stronger 9 fet design from a 6 fet design, for the 25A models. This new controller is due in May, and kits are already on Order. To be perfectly honest, the BBS02 kit works quite well on around 48V 20A. Of course it is very strong in standard form, pulling almost 30A, but you do need a powerful battery to work well at 30A and there are doubts about the long term reliability of those controllers running that power level. The later versions of the 25A controllers did use a temp sensor in the controller that would reduce the current if necessary, so they should be reliable.

 

[tony2311]

its 1409 does that make it a 6 fet or 9 fet?

 

[tony2311]

also what battery should i buy. its a leisure bike and will use it for trips around 30miles at half assistance.
was thinking of 48V 11.6Ah Lithium Ion Frame Battery Samsung Cells + 2A Li Ion Charger from uk supplier for £285 or where can i buy a higher AH so i dont have to worry about battery power. type of cell?

 

[Fordulike]

its 1409 does that make it a 6 fet or 9 fet?

Well according to Paul at em3ev, the new controllers were being fitted to units in May 2014.
Therefore, it's very likely that the one you mention is the new 9 fet.

 

[Fordulike]

also what battery should i buy. its a leisure bike and will use it for trips around 30miles at half assistance.
was thinking of 48V 11.6Ah Lithium Ion Frame Battery Samsung Cells + 2A Li Ion Charger from uk supplier for £285 or where can i buy a higher AH so i dont have to worry about battery power. type of cell?

I'm running one of those Samsung 48v 11Ah batteries on my 750w 25A. I would say that 30 miles is doable, using the lower PAS settings.

 

[Kinninvie]

Your motor is September 2014 so is a 9 fet.

 

[tony2311]

thanks for the reply. just thinking the battery might not be enough if only 30miles on mid setting. what will be the ideal battery if i wanted say 30 on high setting or 50miles on mid setting

 

[Fordulike]

thanks for the reply. just thinking the battery might not be enough if only 30miles on mid setting. what will be the ideal battery if i wanted say 30 on high setting or 50miles on mid setting

I would personally go for the 11.6Ah battery, plus a spare. Then pop the spare into a slim back pack, so it doesn't jiggle around, and swap it when needed.
They are actually surprisingly light.

That way you could buy the batteries from the UK with warranty.

Buying a large capacity triangle frame battery, from the likes of em3ev in China, will work out very expensive, once delivery and import costs are added:

http://em3ev.com/store/index.php?route=product/product&path=35&product_id=123

 

[tony2311]

many thanks for your help. i have settle for two 48v 11.6ah battery

 

[tony2311]

eclipise bike doesnt have it in stock anyone else stock this battery in uk?

 

[Nealh]

Try Woosh or Panda.

 

[trex]

woosh won't sell you 48V 10AH battery for 750W BBS02. They say it can't support that much power.
Their batteries can only support motors up to 500W.
They'll sell you BBS02 48V 500W with batttery.

 

[tony2311]

is this any good for bbs02 48v 750v?
http://www.ebay.co.uk/itm/48v-20Ah-LifepO4-battery-upto-1500w-Samsung-cells-uk-seller-free-postage-/252009862360?pt=LH_DefaultDomain_3&hash=item3aacf554d8
seens very cheap. is it any good at all?

 

[Deleted member 4366]

Something not right. It says Samsung cells, but as far as I know Samsung don't make LiFePO4

The description is for a LiFePO4 battery, but the charger says 54.6v. The correct charge voltage for LiFePO4 is 58.4v

IMHO LiFePO4 is too heavy for a bicycle. Do you know how a 7kg battery feels on a bike? Where would you put something that size? Make a cardboard box that size and see where you can put it.

 

[tony2311]

thanks d8veh. it just sound so cheap, i just have to wait till mid jul when elispe will have some 48v 11.4ah battery in stock

 

[Deleted member 4366]

You can get them from BMSBattery too, which is where I get mine from.

After looking at it again and some other listings, I think that other one is a standard 20Ah LiFePO4 battery. The guy has just added "Samsung" because that's what a lot of people want. Naughty really. The charger has an internal adjuster to set it to the correct 58.6v, so that's not a big problem really, but the main thing is the extra 3.3kg on top of a 09 bottle battery and the shear size of it.

There's been a few instances of people buying big LiFePO4 batteries like that that didn't work because the cells in the corners got squished due to the weight when they were handled badly. Personally, I think LiFePO4 has had its day for electric bicycles. It maybe still OK for a trike, when you can fit it low under the seat.

 

[tony2311]

so should i buy this battery or is there a better one?
https://bmsbattery.com/ebike-battery/684-48v116ah-bottle-09-panasonic-battery-charger-battery.html