21700 cells,

[Nealh]

My new cells turned up today, superb service from Ben and the team at Fogstar. Ordered one day and they arrived within 24 hrs via DPD. Cells are so scarce at the mo but they have had a fresh delivery of Molicel P42A, so I ordered 24 for a 8.4ah/369wh 44v battery build for the Kona ute/ Cotic roadrat and some cell holders. All in inc £8 p&p the cost was £119.
This is a simple 2p 12s pack build for lightest weight possible.
I checked the date code and these ones are pretty much fresh off the line, 12 Nov 2021 is the cypher for the code.
Post pics of the cells later today.

 

[Nealh]

Cells sitting at 3.51v which is prety much that which all cells I have had are charged to from the factory.
By most standards not many cells but then again I'm not after mega current draw or throttle usage.

As nearly always the case cells come in a small compartmented box.


Date code 2LB12.
2 = Milenium date.
L = denotes year 21.
B = month Jan - Sep is 1 - 9 then strangely Oct - Dec is A - C.
12 = day of month.
So we can deduce 2021 Nov 12 as production date.

I don't know what 177 or 113 denotes, but believe 01 is the production run.



The example cell used on the website has a date code 2i A07 for 2018 Oct 07.

 

[Woosh]

21700 cells give the best value for money at the moment.
I have started to bring in Panasonic 21700 5000mAH packs, using DP 21700-4C case.
They will be on sale from next month.

 

[Nealh]

Moli also have two other large mah cells, the P45B /4500mah another high a rated cell of over 30a rating and the M50A /5000mah a 10- 15a rated cell. The P45B is said to out perform and be better then the P42A but isn't available just yet, it is expected possibly by the end f the year. It is approx 4 years since the P42A was released and 21700 is now seeing some improvements but one expects like the Samsung 50s the P45B won't be cheap.

The P42A can deliver 71w continuous so for my 2P build a min of 852w output.
Compare that to the LG hg2 I use in my bottle battery as 12s 2p and the cell is rated 26.2w continuous and as Tony says they are best value for capacity and power.
Both the Lg hg2 and P42A are high current cells the former a 18650 and the latter 21700, the 21700 having 270% more continuous output then the 18650 but only for a 23% price increase and a 36.5% increase in capacity which also means greater range.

One has to choose the cell for the applicaton for my 2P builds a 10a rated 21700 won't quite cut the mustard for higher power use so one has to go for a cell with the higher current rating for longevity.

 

[Nealh]

What config are you going to use Tony 10s 4p or 13s 3p ?

 

[Bonzo Banana]

I bought a pack based on these cells;

3.82￡ 58% OFF|Liyv|liitokala Lii-50e 5000mah 21700 High-power Rechargeable Battery 5c

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

It was this pack below which at the time was £80 with free postage (plus VAT). I've not used this in a build yet but it took 7-8hrs to charge with a 2A charger so based on that I feel they are genuine capacity using that likely flawed logic. Presumably the LiitoKala 21700 5000mAh 3C(Lii-50E) are a re-wrap of some other 5000mAh cell. It works out I have 13x3 cells so 39 cells, it was the 48V 15Ah pack I bought. I think previously it was £34 for 20 cells so about £68 roughly for the cells of my battery pack but now its £50 for 20 cells so £100 just for the batteries. Shortly after ordering the battery pack went up to £100 plus VAT and now its at £130 although the pack with twice the cells of mine is at £200 so my pack has become far less competitive in the range. This is unbelievable inflation as its only a few months. I guess the issue is when you are buying from a factory in China any decrease in sterling value, or factory pricing increases are reflected very quickly. If you are buying from an importer in the UK the inflationary price increases could be delayed for a short while as the stock they are selling has come in at a lower agreed price than if they bought today especially if its been shipped on the water so takes weeks to get here. Surely this will all have a knock on effect to all ebike batteries and pre-configured ebikes or there will be pressure to lower battery pack capacities or use cheaper cells to maintain pricing. I have never known in my life a time of such huge price inflation.

107.52￡ 42% OFF|48v 50ah Lithium Battery | 48v 20ah Li Battery Pack | 21700 Battery 48v 25ah - 48v 30ah - Aliexpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

 

[Woosh]

What config are you going to use Tony 10s 4p or 13s 3p ?

10s4p for 36v 20ah and 13s3p for 48v 15ah. They cost same as 36v 17.5ah and 48v 12ah built with Panasonic 18650 3500mah cells.

 

[Nealh]

A genuine A1 Sam 50e is a min £4.25 cell, they could possibly be re wraps if they buy them cheap enough from factories as non top grade cell so spec B - E cells at a lower price point, these cells won't meet the Sam QC procedure so I expect they could possibly be sold off to third parties and re wrapped. But would Sam risk selling lower grade cells off .

We have seen with billboya's battery which is the same by the sounds of it, he is now after several months having charging issues which may be down to lower grade re wraps or the bms quality.

 

[peter.c]

Not all 21700 cells are equal my first experience came with risen motors 48v 19.2 ah sold as Panasonic tesla cells £330 with a 5 amp charger 35miles+ even on a bbshd .
Then had a Liitokala 48v 20ah on almost the same deal as above, beware can take 2 +months for the slow boat free shipping . No charger- no on off switch-only a 30 bms-no fuse fitted.
But once charged 9 odd hours [they recommend max2 amp] as expected ok on a bbs02 but no use for a Bbshd due to the bms .Own brand cells inside with holders [now has black shrink wrap]
But it will not fit in a standard hailong battery case the 13s 4p is an awkward size but 52 cells is a great weight saver. Low battery cut off at 42v after 50 ish mixed off road miles on a bbso2 so suspect nearer 15-17.5 ah capacity than 20 ah
You get what you pay for

 

[Bonzo Banana]

Not all 21700 cells are equal my first experience came with risen motors 48v 19.2 ah sold as Panasonic tesla cells £330 with a 5 amp charger 35miles+ even on a bbshd .
Then had a Liitokala 48v 20ah on almost the same deal as above, beware can take 2 +months for the slow boat free shipping . No charger- no on off switch-only a 30 bms-no fuse fitted.
But once charged 9 odd hours [they recommend max2 amp] as expected ok on a bbs02 but no use for a Bbshd due to the bms .Own brand cells inside with holders [now has black shrink wrap]
But it will not fit in a standard hailong battery case the 13s 4p is an awkward size but 52 cells is a great weight saver. Low battery cut off at 42v after 50 ish mixed off road miles on a bbso2 so suspect nearer 15-17.5 ah capacity than 20 ah
You get what you pay for

I actually got my Liitokala battery pack in about 2-3 weeks I think and strangely it was sent from a UK address. It was from a trading estate in somewhere like Solihull. I assumed it was bulk shipped with many other battery packs and then individual sent from within the UK. I've not tested capacity other than charging which was 7-8hrs as expected for a 48V 15Ah battery pack when used with a 2A charger. However some reviews which occasionally needed translating showed people who had tested their battery packs showed true capacity, sometimes a little below and sometimes a little above and just about all reviews were positive and seemed to come from genuine customers.

Obviously I'm not here to state its the finest battery pack ever, I paid £80 plus VAT including delivery for 48V 15Ah 2100 battery pack and also cashback tracked through topcashback but whether that is paid is another matter. So it was about £96 and the charger was about £7, if all the cashback is paid I'm below £100 and if it isn't just above. To be honest I wouldn't have a problem with a 30A BMS but then that's because my battery pack has smaller capacity. I don't have any high power mid-drive motors. The most powerful motor I have a is a 500W geared hub motor laced to a 20" wheel.