BikerToCycler

Hello guys need some advice I have a couple 48v controllers lying around and want to feel the performance of 72v before I fork out on a £££+ Sabvaton and £££ on a qs205 I have what looks like a well built 15 fet controller can anyone identify it and give advice on what caps/fets are the best It has survived 100A bursts without warming too much so I hope for 72v 50A but don't mind if it dies after a few uses I got it free with a motor kit that turned out to be a solid kit compared to newer ones I have come across

Had this battery custom made for me tried it out once as it just arrived 2 days ago and had my bike running at 35A (controller maximum) without any voltage sag that i noticed (display battery bars going down etc) It was built with the best cells and i made sure the seller sent me pictures so i could see the build quality without stripping it down. Problem is i ordered this before deciding i want a full suspension bike build next and so i want a more backpack friendly size and shape might even experiment making my own next as buying them costs so much more than the bare cells. Just for reference i paid £548 posted and import charges included and its seen 0 use apart from any discharge tests the seller did and my brief test of the battery on arrival. Looking for offers so i can decide wether its worth selling or just put up with a triangle shape in my back. Also if anyone knows of cheaper battery builders in the EU let me know. Edit: Comes with charger, voltage display for checking charge level when off the bike and xt90 is the connector it uses.

Also by fill out and return do i have to post and wait?

Are these kits any good currently 48v 1000W kit is £179 if i remember. Seems to use Kunteng controllers and LCD units as far as i can find out by searching. I have a 13s4p 20A max battery right now so 980W hoping to be able to limit the controller using the LCD as voltage sag cuts my battery out now and again even at 20A Final thought, Does anyone know if 590$ including shipping and seller pays tax from china to EU is a good price for a 14s5p pack of Sanyo 3500GA cells with 50A/70A BMS and a charger? I tried to find similar in EU but there was nothing i could see. I requested a spare BMS and also a volt meter on the pack so i could check when charging seller included it all for free.

Will use it to adjust more, it began cutting out again so i tested stalling the motor on highest setting after cutting one of the shunts off And it was fine even under stall, then after a short ride it was cutting out again and not cuts out when stalling. It seems the shunt trick works but after a bit of driving the controller is slowly increasing the power?

Just got one £8 on ebay

This bike is just for fun offroad so not for keeping fit i am underweight if anything. Do you have a good idea of how to measure the current under load? I dont have lcd just a cheapo led monitor i have velcod my iphone to the handle bars for speed/ distance

So had a read around and seen another of your posts mentioning you shaved the shunts. So googling found out what a shunt is. Located mine and shaved (20% of the shunt) hoping for 25>> 20 Resistance before shaving was around 3ohms after was 4.5 so i shaved abit too much maybe but the readings were not very reliable anyway. So i test by holding break and pushing full throttle the bike nearly shot through my neighbours bedroom wall!! How reducing the Amps results in such crazy power gain i am unsure. However it now hasnt cut out i will test it out and hopefully it stays working Thank you for the help

http://imgbox.com/kKQtxygK

http://imgbox.com/kKQtxygK http://imgbox.com/Bhq1tuWI http://imgbox.com/KVfbR0FM http://imgbox.com/Ja5jzZGO

I am learning on the go and i worked them figures out too although i thought 5.2 is the safe current not max as it can go full power just not sustain it and eventually cuts, the seller knew very little about batteries and kept saying the cells are not important its the BMS which i knew was BS either way i now have managed to get the partial refund so will get a 750 w motor for my next build which will go perfect with this. Thanks for the help i will try contribute to this forum as i learn more and start building better bikes.

Aliexpress offer a guarentee of partial refund if not as described i have had an offer of £30 from him but i asked for £50 i think at £180 the battery is a bargain as its actually really well made just 20A instead of 25A continous as he described In terms of recell do you mean just get them to add an extra 13 batteries in 13s5p? Will it fit or will they replace all my brand new 26F batteries i can image that to be expensive

One last bit of advice, seller is offering a free 30A bms but i dont think this will solve the problem as the cells have 20A peak output. Am i correct?

2600 mah 3.7v 5.2 A are the specs for the 26F i found online. 13s4p would get me the 48v and 10.4ah So that gives 5.2x3.7/48 x13x4 i think this is how you calculate this? Thats 20A and so this is definately my problem the motor seller told me the motor and controller are rated 25A Now to talk to the seller, thank you all for the help any suggestions of someone in UK who can build batteries? I would give it a go but don't have a battety spot welder and would love a triangle bag with ~20ah 48v

Thank you all for the help the cells are advertised as samsung 26F cells although i will try to take it apart to test. I bought on aliexpress and so i will be able to make a claim and receive a refund if the batteries are not what they are claimed and or the battery does not put out 25A continuous. I am having a problem getting the housing off and don't want to damage it anybody had experience taking apart this style of battery This is the same item as the one i bought http://s.aliexpress.com/MNN3EFFr