Nkon - putting 20 high Amp discharge cells in a battery for 95€ or 40 lower discharge cheaper ones in a bigger battery to get up the same hill my vote is for small and light weight powerful option.

 

I'd vote get the cheaper lower discharges ones. That's what Tesla did with load of ncr18650b. That way you only do shallow cycle and your pack last ages .

 

My 200 cells pack of ncr18650pf built almost 3 years ago is still working nicely and with good range

I'd vote get the cheaper lower discharges ones. That's what Tesla did with load of ncr18650b. That way you only do shallow cycle and your pack last ages .

 

My 200 cells pack of ncr18650pf built almost 3 years ago is still working nicely and with good range

 

9.6 kg battery + 13% hill =

 

491€ vs 99€ also

So what cells + retailer would users go for now if you were ordering. Unsure between the 3500 and 3000mah cells form Samsung (nkon )

Nkon is still the place to go. Your choice of cells is dependent to a degree on the number of cells, current draw and the range you want. The largest capacity cells are not suitable for high current draw, but are great if you want a small high capacity low current pack. Samsung 30Q are a good balance between capacity and current or range and power.

So what cells + retailer would users go for now if you were ordering. Unsure between the 3500 and 3000mah cells form Samsung (nkon )

 

nkon - good prices, in the EU, fast shipping

 

Samsung 30Q - there is 0.11€ difference between it and the 35E but the extra 5 Amp discharge is more important for me than the extra 500 mAh capacity.

 

Say I had a 30 km daily commute or just need a tiny battery for knocking about town with about 35 km range:

 

Sony Konion US18650VTC6 3120mAh - 30A - 2P10S 6 Ah battery weighing about 1 kg and cost under 100€ cells (shipped) + BMS

 

Or a longer commute or need for more range:

 

Sanyo NCR20700B 4250mAh - 15A - 3P10S 12 Ah - 184€ and about 2 kg

Thanks guys,

 

I think a 10s2p pack will be big enough for now, with the potential to add a second pack in parallel for longer trips.

 

The controllers we have are rated for "36v – 15AH Max-7AH". So I would assume that 2 10Amp cells (or even 8Amp cells) in parallel would be adequate to max the controllers output such that the controller becomes the limiting factor, therefor worth going for the 3500mAh 35e's.

 

Commute would be a 20 Mile round trip, using the motor for some assistance.

 

Have I understood the rated inputs/outputs correctly there?

The controllers supply current, which is measured in amps not amp-hours. the only thing you need is the maximum current - 15A in this case. Your BMS needs a margin of 5A, and so do the cells, so you need cells capable of supplying 20A (10A each when 2P) and a BMS of 20A.

Have I understood the rated inputs/outputs correctly there?

You have, but it is good practice to only use 50% of a cells output ability to maximize cell life. So, if you need 15amp max and plan a 2P10s pack, it is better to use 15amp cells. Also the capacity drops as you approach the max. output, so you may find the the 30Q will give you a similar range to the 35E.

Thanks wheeliepete+d8veh, that's the advice I was after I know about aH vs the max output current but wasn't aware of the general rules regarding best practice and how the batteries perform in the real world.

 

Seems like high drain would be more suitable for my situation, rather than higher capacity. This will also allow for future power upgrades slightly more easily.

 

With that in mind it would appear the 30q's are currently the best value option, I'm not sure it's worth the extra for the 3120mAh Konions (+20euro)?

Build one of each-just make sure the bigger pack goes on your bike:D

35E is apparently a so-so cell, 8a is about it's rating.

30Q, HG2 or VTC6/6A are the stand out cells for a 2P config.

I got my last cells from here:

 

http://www.ebay.co.uk/itm/4x-LG-Genuine-Lion-Batteries-HG2-18650-3000MAh-20-30A-IMR-Rechargeable-Batteries/201805669216?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

They're sold out.

 

Are these any good?

https://www.ebay.co.uk/itm/E-bike-Bateria-11600mAh-11-6Ah-36V-40x-Panasonic-NCR18650PF-10S4P/282633317787?ssPageName=STRK:MEBIDX:IT&_trksid=p2055119.m1438.l2649

They're sold out.

 

Are these any good?

https://www.ebay.co.uk/itm/E-bike-Bateria-11600mAh-11-6Ah-36V-40x-Panasonic-NCR18650PF-10S4P/282633317787?ssPageName=STRK:MEBIDX:IT&_trksid=p2055119.m1438.l2649

 

All you get is a welded shrink wrapped pack, you still need to add a BMS which means removing the shrink .

PF test independent review below not over whelming.

 

https://www.e-cigarette-forum.com/threads/panasonic-ncr18650pf-10a-2680mah-18650-bench-retest-results-an-ok-low-capacity-10a-battery.774091/

Starting building my own pack after being inspired by d8veh's lightweight build.

 

Before I commit to this is there a better layout possible (I don't think so but don't want to have missed an obvious trick!)

What are you trying to achieve, 36v, 48v, 10s3p,10s4p etc?

10s2p, that picture is1 of 2 cell sets in the same configuration, making a 5s2p. Two of these on top of each other will make the 10s2p configuration, probably with a link wire between the 2.

For 10s2p, I'm I correct in assuming you'd need 2 of the BMS boards linked to earlier at AliExpress (I've not been able source them from anywhere else) to cope with the 20 cells?

 

Are there readily available low cost BMS boards that can handle 10s2p, 10s3p, 10s4p, etc. or can the above BMS cope with managing cells connected in parrallel?

 

I've also seen Arduino based DIY BMS projects out there, but not sure how suitable/reliable/safe they'd be for an eBike application.

Edited July 30, 20187 yr by grazie

One BMS can deal with any number of parallel cells, just get the one to suit the no. of series cells you have. I've used this one on several 36v 10s packs.

 

https://www.ebay.co.uk/itm/Battery-Protection-Board-BMS-PCB-10Packs-36V-10S-Li-ion-Cell-Max-40A-Balance-BSG/122928984391

Thanks Pete. Any views on these (or others) from Amazon? Only asking as I got Amazon credit to use up. Obviously, most interested in the first listed due to its claimed 35A rating.

 

https://www.amazon.co.uk/Battery-Protection-Asixx-Ternary-Balancing/dp/B07F1TK7SQ/ref=pd_sbs_107_1?_encoding=UTF8&pd_rd_i=B07F1TK7SQ&pd_rd_r=42f4cd45-9572-11e8-9a6f-ad3730aad927&pd_rd_w=mOo8A&pd_rd_wg=pOrb2&pf_rd_i=desktop-dp-sims&pf_rd_m=A3P5ROKL5A1OLE&pf_rd_p=5179604776422437276&pf_rd_r=T4V5PJ6Y87NT4700Y818&pf_rd_s=desktop-dp-sims&pf_rd_t=40701&psc=1&refRID=T4V5PJ6Y87NT4700Y818

 

https://www.amazon.co.uk/Sharplace-Lithium-LiFePO4-Protection-Balancing-multi-color/dp/B077KWVVNK/ref=pd_sbs_23_4?_encoding=UTF8&pd_rd_i=B077KWVVNK&pd_rd_r=0ac604d6-9572-11e8-9a6f-ad3730aad927&pd_rd_w=hjU1m&pd_rd_wg=l0nIi&pf_rd_i=desktop-dp-sims&pf_rd_m=A3P5ROKL5A1OLE&pf_rd_p=5179604776422437276&pf_rd_r=AX8CCZ7N2CBXZM682VJ2&pf_rd_s=desktop-dp-sims&pf_rd_t=40701&psc=1&refRID=AX8CCZ7N2CBXZM682VJ2

 

https://www.amazon.co.uk/MagiDeal-Lithium-Battery-Protection-Balance-multi-color/dp/B077X7CCQB/ref=pd_sbs_23_5?_encoding=UTF8&pd_rd_i=B077X7CCQB&pd_rd_r=0ac604d6-9572-11e8-9a6f-ad3730aad927&pd_rd_w=hjU1m&pd_rd_wg=l0nIi&pf_rd_i=desktop-dp-sims&pf_rd_m=A3P5ROKL5A1OLE&pf_rd_p=5179604776422437276&pf_rd_r=AX8CCZ7N2CBXZM682VJ2&pf_rd_s=desktop-dp-sims&pf_rd_t=40701&psc=1&refRID=AX8CCZ7N2CBXZM682VJ2

Not used any of them myself , but all look suitable. This is the one I linked to above.

 

https://www.amazon.co.uk/Sharplace-42-45V-Battery-Protection-lithium/dp/B072FQ41V9/ref=sr_1_3?s=electronics&ie=UTF8&qid=1533122695&sr=1-3&keywords=10S+BMS