Thankyou to the Endless Sphere community for your help as I have moved into ebikes over the past year,
I enjoy how it combines my enjoyment of technology and riding. And, enables people of various abilities of fitness and health to ride together. For example, my 70+ mum to started riding again when she got an ebike, and allows us to ride together on 40+km rides.
The idea of the new battery build came when I was seeking more torque up hills from my 36v battery. After some research I found my controller on the Kristall E5 250w could handle 48 volts. And, a decent capacity quality 48 volt battery for this bike would cost over $700AUD (Reention Tigershark case). This then started me on the battery build journey, and as we have about 15 of the Kristall ebikes in our immediate and extended family, re-building batteries was going to be needed in the future, and self building enabled me to choose features, cell quality and capacity.
This was my first battery.
The battery build:
Research:
Endless Sphere
Books:
- Micah Toll's 'DIY Lithium Batteries ' and 'Ultimate DIY Ebike Guide '.
- Design: see prior post.
Bill of Materials (links at bottom):
Bike: Kristall E5 with G51 LCD and controller built into Tigershark cradle. I have purchased a couple more Kristall ebikes, and the OEM advised they use Lvdong controllers.
Battery case [1056] : 65 cell Tigershark
BMS [1057] : BeMuchSafer 48V 13S30A BMS Separate Port 13S 30A.
18650 cells [1102]: Vapcell F34 3400mAh (3200 mAh tested capacity using Xtar VC8 Plus).
Nickel strip: same seller as 18650 batteries (tested 100% nickel after doing salt water scratch test).
Kapton tape: same seller as 18650 batteries
Various wire gauges for build: [1109] . For example from load to BMS, power and switch etc.
Connectors heat shrinkable: [1112] wanted to enable separating battery from case and bMS
Heat shrink: [1113]
Crimper [1115] : already had. It is the Prostormer 3 in 1 Wire Stripper
XT60 pre soldiered [1117]:
Soldering iron 80w [1119]:
Spot welder [1120]: Sunkko 737DH (240v version as in Australia). Same seller as cells.
Flux: LA-CO acid free.
Soldier lead free [1128]: 0.8mm
Antistatic ESD Soldering Mat [1122}
Soldering helping hands: already had
Heat gun [1135] : XU1 2000W heat gun
Glue gun [1136]: Ozito 30W 11mm Glue Gun Kit
Battery waterproof cover [1138]: for when using batteries on bike. Building the battery you can see where water could get in any of these (e.g charge port, USB port, switch etc, even with rubber cover, where battery halves come together etc)
Switch on/off [1140] : as melted first one soldering wires to switch, as didn't realise you can remove them to make it easier.
DC charge connector [1141]: same as above
48V 4A charger [1145] : same seller as Tigershark battery case
Waterproof tape: used to tape up around the two parts of the battery as additional water protection.
Magnifying glass with x10 magnification [1156] : to see the AWG on the BMS wires to purchase the correct wire guage.
Lessons:
Time: The build took some duration, due to things like melting the switch and DC jack.
Wire gauges: I found where possible keep wire gauges 16AWG or above to enable to use crimp connectors, even for switch.
Commercial battery cases don't have a lot of space: I wanted a bluetooth BMS to monitor charge, discharge and wattage. But, I wasn't able to locate one that would fit. Also, when you use connectors you have to carefully work out where to fit them. You can see why there is no movement in these types of battery cases.
Battery case parts availability: I used the Reention Tigershark battery case as I wanted to use the same battery mount on our Kristall ebikes, and to enable the battery to be used across our Kristall bikes as well as extended family (for longer rides we share batteries). But, if I was choosing a battery pack if I was starting a new build, I would choose another model (e.g. Reention Hailong). As, Hailong battery case parts are a lot easier to locate and cheaper (lots of sellers helps keep prices low) . Hailong enables you to use 18650 and and 21700 cells.
Connectors: love the heat shrink connectors to provide additional support/reduce wires pulling out. But, in the future I think I would reduce the number of connectors I used, and just soldier battery wire directly to the switch etc to remove issue of fitting connectors into the case.
Battery LED indicator PCB on case: I removed the LED indicator, as the wire was so thin (26AWG) and came away from soldier, and I couldn't fit a larger AWG due to the positive and negative soldier points so close together. So removed to minimise risk of sparking if the wires broke away from the soldier and sparked or worse: .
Battery spot soldier design: per my previous post, I would have designed the layout differently to fit the nickel strips between the battery plastic holder cut outs, and not at times having to go across them.
Battery cell purchasing: the other seller I am going to look at purchasing from is Batteryhookup who ship to Australia (link below). They are recommended by Micah Toll from Ebike School (for 5% discount use code 'ebike' )
https://batteryhookup.com/products/30-100-new-samsung-inr186...
Parts availability to enable longevity of use of bike:
When building or purchasing ebikes, check you can get parts, or are able to change out the part to another brand.
Example of the above, is the controller for the Kristall E5 Tigershark integrated battery mount that is installed in the location of the water bottle holder mount (controller is in the mount where battery fits on bike) is provided by Lvdong controllers, but Lvdong is difficult to locate parts for from my searching. But, as the battery , controller etc is not built into the bike/frame, I could change the LCD, controller, battery mount etc to another brand, and even buy a new wheel with hub motor. Where as some of the newer bikes have everything integrated into the frame, so you are generally stuck with that controller, battery case brand etc , so what happens when the company stops making those parts (e.g. brands such Reention with battery models that have the frame built around/integrated with the battery, tube batteries etc).
Photos and YouTube of parts of build:
- photos of build: https://photos.app.goo.gl/rCkpHC9xCCGrHXyr8
- Testing BMS switch is working: https://youtu.be/rbg_Ys2_hP4
- Kristall E5 ebike LCD/controller change from 36v to 48v : https://youtu.be/i-9bGoqTHJw
- Sunkko 737Dh spot welder overview and settings I used (Australia 240v): https://youtu.be/rA0saULaSIg
Thanks again to everyone who has shared their knowledge in this community, hopefully others find this post useful.
[1056] Battery case : https://www.aliexpress.com/item/32720266395.html?spm=a2g0o.order_detail.0.0.6b65f19c5meqyg
[1057] Controller: https://www.aliexpress.com/item/1005003362901037.html?spm=a2g0o.order_list.0.0.2f331802iySDrf
[1102] cells : https://www.alibaba.com/product-detail/Good-consistency-High-Capacity-Vapcell-F34_1600375345173.html?spm=a2700.9114905.0.0.YrYMfM
[1109] Wire seller: https://mucg.aliexpress.com/store/911945026?spm=a2g0o.order_list.0.0.2f331802iySDrf
[1112] Connectors https://www.aliexpress.com/item/1005001698425142.html?spm=a2g0o.order_list.0.0.2f331802iySDrf
[1113] heat shrink https://www.aliexpress.com/item/1005001393566382.html?spm=a2g0o.order_list.0.0.2f331802iySDrf
[1115] Crimper https://www.aliexpress.com/item/32810871209.html?spm=a2g0o.order_list.0.0.2f331802sZoJ6L
[1117] XT60 https://www.aliexpress.com/item/1005001860363771.html?spm=a2g0o.order_list.0.0.2f331802sZoJ6L
[1119] Soldering iron https://www.aliexpress.com/item/1005002630432331.html?spm=a2g0o.order_list.0.0.49491802MArM3K
[1128] Solder lead free: https://www.bunnings.com.au/craftright-15g-electrical-solder_p0237250?region_id=116215&gclid=Cj0KCQjwyt-ZBhCNARIsAKH11742dflSCgIeL8tGTmvQ1DAEdWhata97NhBz8drCTcFS6N1ZujQvfxcaAlI0EALw_wcB&gclsrc=aw.ds
[1122]: Soldering mat: https://www.aliexpress.com/item/1005004241859889.html?spm=a2g0o.order_list.0.0.49491802MArM3K
[1135] Heat gun : https://www.bunnings.com.au/xu1-2000w-heat-gun_p6290580
[1136] Glue gun https://www.bunnings.com.au/ozito-30w-11mm-glue-gun-kit_p0098549
[1138] waterproof ebike battery bag https://www.aliexpress.com/item/1005003619377805.html?spm=a2g0o.order_list.0.0.49491802MArM3K
[1140] on/off switch https://www.aliexpress.com/item/4001332967504.html?spm=a2g0o.order_list.0.0.49491802MArM3K
[1141] DC charge connector https://www.aliexpress.com/item/1005002915367593.html?spm=a2g0o.order_list.0.0.49491802MArM3K
[1145] 48v charger https://www.aliexpress.com/item/32794346217.html?spm=a2g0o.order_list.0.0.21ef1802DHY1vH
[1156] Magnifying glass https://www.aliexpress.com/item/4000544359722.html?spm=a2g0o.order_list.0.0.21ef1802DHY1vH