Hydra Batterie Question

Well just rotating it so valve is on top works. It creates enough space for the spare battery to fit. Without spare battery there the shock looks a little weird like that but not a big deal. Need some type of pad to put in between spare battery and frame, and maybe some sleeve or something to keep dirt/water off it. And then 2-3 straps that reach all the way around to hold it in place.
20220214_102837.jpg
 
Last edited:
Yoga mats are the ideal rubbery material for that :)
A Neoprene sleeve would be good too.
 
So you would just swap out the depleted battery for the "spare" correct? That way you wouldn't need to figure out how to connect up the power wiring and you could still charge both battery's separately so their own BMS would operate independently.
Easier than carrying in a backpack and the weight is right where it needs to be.

What would the bike weigh in at with both battery's installed?
 
Yeah this is just an alternative to carrying a 2nd battery in backpack, strap it to frame instead. And yeah half way through ride you just gotta swap the two.

You could probalby make some frankenstein setup with some way to automatically switch packs, or run them in parallel or something. But would not look clean at all and require running wires outside frame. I think a Frey Beast is way to go if you want 1500wH all the time. This is more once-in-awhile you carry a 2nd pack and partway through ride you take 5 minutes to swap packs.

No idea on weights, I don't have a scale that'd work.
 
I figure you could have a second bottle-mounted shark pack wired in (either with the switching dual battery adapter or in parallel), but if you've got the second internal battery already, not so much.
 
bexamous said:
You could probalby make some frankenstein setup with some way to automatically switch packs, or run them in parallel or something.
Click to expand...
I had actually modeled a possible solution a while back, But it would not be cheap to 3d print all the parts :)
 
How would you route wires into frame? I don't think there is any nice way in? I mean it would be cool if it was a clean solution. It would kinda make Frey Beast pointless if you could [easily] switch Hydra between 850wh and 1700wH.
 
My hope impression is that there could be a connector at the bottom, and enough room inside the frame between the bottom of the internal battery and the motor for the dual connector component WW makes.
Without a bike to examine, this is all conjecture though :)
Cover to battery clips-1.jpg
Full integration-asy-3.jpg
Full integration-asy-0.jpg
 
This is the ideal solution I was envisioning, but thought noone would go to the effort of implementing.

I don't have my bike yet, so I don't know how you might wire this in though...
 
Haha okay that would be a clean solution.. but bit more than I'm capable of. ;) Yeah I don't know how much unused space exists, in frame, but I think there is enough. I was looking up Dengfu E10 builds and saw someone who was opening battery compartment a bit more becuase there is some unused space they wanted to fill with battery. I'll try to find that again, I recall it had some good pics.
 
Not knowing what the inside of the battery compartment looks like but Im guess that the lower section has the connection points, Typically like a shark pack or close to it. Different battery I know but probably pretty close.
Having a baseplate for the upper battery to slide or lock into would help keep it in place. drilling a small hole for the wires to pass thru tinto that inner void might be doable. Im sure there's a void in back of the existing battery for the cables to be routed up to the stem area. Wouldn't see any wires at all.
All that battery stuff is modular as someone puts it all together in the proper sequence so reverse engineering it would be easy.

You could always modify the wiring coming directly out of the motor. We did that for the motor connections on mine and a couple of friends motors. Longer motor connection with some slack is now in the downtube section with XT90 connectors instead of having the Anderson's above the motor assembly.
Easier to mount motor without worrying about that connection coming loose to.

bexamous post up a pic of the inside of the existing battery section with the battery removed if you get a chance.

Scrambler excellent job on the spec drawing.
 
I tried to take some pictures, they suck.. see this thread on emtbforums: https://www.emtbforums.com/community/threads/dengfu-e22-frame-thread.26880/#post-375496

That first post has some good-as-it-get pictures. In downtube on either end of battery are the battery mounts and on other side of them tube is mostly partitioned. Frame isn't totally between different sections. No real space in battery compartment section. Maybe you could mount something over the motor.. not sure how much space is there.

I dunno not nicest solution but just putting two packs in parallel when both packs are fully charged doesn't seem like huge concession. Maybe put 20-25a fuse on external pack just-in-case... with mismatch you'd either blow fuse or worst case you charge one pack ~1.2C for a bit.
 
By headtube on either side are openings for internal cable routing. What if I move all cables to one side and basically have a XT60 (or XT90 I forget how big opening is) on the other side which is in parallel with internal battery. Bike will basically be stock except it'll have a XT60/XT90 near headtube.

And then when want to bring 2nd battery, charge them both up, strap 2nd to frame with a few cinch straps and have a 8" cable from external battery to headtube.

I think that'd be kinda nice. I did think putting the two batteries in parallel wouldn't be a big deal, I'd be okay charging them up first and checking voltage is same-ish before putting in parallel. But then now more worried about what happens if while in parallel one battery 'turns off'.. eg what happens if I press button on downtube that turns off internal battery? Or external battery just a poor connection causes BMS to turn battery off for a bit and when two packs get further apart in voltage and vibration then casues poor connection to make contact again and BMS turns pack back on. I dunno.
 
@bexamous - Suggest use diodes to isolate your battery packs. Do not just slap two packs in parallel. WW has a combiner….
Also, try removing the decerative panel on the Bafang covering the mounting bolt/nuts. That is where the frame battery connects to the motor. Maybe drill a rat hole on that cover for your external wires…
-BB
 
@bexamous WattWagons use to sell a dual battery connector for that purpose, but I no longer see it on their site (all accessories appear to be gone).
You may want ask them if they still have it for a price.
 
I found the archived page to it on the wayback machine :)
web.archive.org

Dual Battery Converter - instantly double your riding range!

Have you ever wondered about what to do with all your old ebike battery packs ? Watt Wagons is introducing an incredibly easy way to use your old battery packs and double your riding range. This converter will only work with two packs of the same voltage (e.g. 2x48v, or 2x52v).
web.archive.org web.archive.org
 
Here is what I used for my EVG battery pack combiner (simple common cathode diode pack)....
I made similar combiners for two of my LUNAtic buddies for their 52V Wolf packs and they added some 21700 14S2P "range extension" packs from China...
FWIIW- That UAV board is damn cool. You will need to deal with cooling though.....
-BB
 
So bike isn't exaclty going to sustain 2000 watts.. but worst case internal pack is on its own and has to put out 50 amps... though I don't think that's actually possible so lets just go with 40 amps max...

uavmapping.co.uk

Dual Ideal Diode V2 – UAV Systems Ltd

Safely connect 2 or more batteries with different voltages to a single supply also protects batteries from dead shorts or other circuit related issues
uavmapping.co.uk uavmapping.co.uk
Uses: https://www.onsemi.com/products/discrete-power-modules/mosfets/fdb3632
9mOhm resistance, ballpark 40**2*0.009 = 14 watts heat. It would actually be higher than this.. even with lot of heatsink its in a small enclosed space above a warm motor. Just seems unrealistic to make work without limiting motor power. At 15-20 amps seems realistic?

Then there are these:
https://www.aliexpress.com/item/4000299576209.html - Quad
https://www.aliexpress.com/item/4000971652693.html - Double
https://www.aliexpress.com/item/4000971604695.html - Single
Uses: https://www.infineon.com/dgdl/Infin...N.pdf?fileId=5546d4624a75e5f1014ac94680661aff
1.5 mOhm resistance, ballpark 40**2*0.0015= 2.4 watts heat, and that's with just 1 mosfet. With two they each do 20**2*0.0015=0.6watts, 1.2 watts for board. WIth 4 they each do 10**2*0.0015=0.15 watts, 0.6watts for board.

Interestingly the double and quad the board size is the same so it kinda makes sense to pay a few bucks extra for the quad to halve total heat. Both the double and quad can get just board or potted with heatsink.. doesn't seem like its same heatsink for both though, and not sure what either of their dimentions are, both seem big. And with how little heat they make all that heatsink is a waste.. and probably won't even fit.

The single can come with a cover, I guess its like a piece of plastic or something? -- They say black or yellow, so yeah not sounding like its going to help with heat at all, only hurt if anything.

The single somes in a few versions, I assume the 100v300a one uses 105N10N5 mosfet, in pictures I see it. Also in description mentions [email protected] for an hour it reaches 36C and [email protected] 41C... doesn't say ambient though, lol.

Realistically seems like single with a little heatsink would be good enough, especially for external battery that has better airflow. For internal could get single w/heatsink or be more paranoid and get quad with little to no heatsinking? Its bigger than single but still just 50x55x20mm, if it fit seems like decent option.

(edit)

Actually another version of single with 80v version: https://www.aliexpress.com/item/4000299511206.html
With: https://www.infineon.com/dgdl/Infin...N.pdf?fileId=5546d4624a75e5f1014aca59127a1eb9
Only 1.2mOhm resistance. And this aliexpress link can get with heatsinks for a couple bucks extra.

Suggestion is with shell (which I guess is not heatsink just some piece of plastic or something) 15A, without shell 20A, with dual heatsink 30A, all continuous. So yeah that seems reasonable to me. They show 25A with dual heatsink stablizing at 45.5C in open air. In frame yeah on a hot day.. yeah starting to get warm.. could put beefier heatsink to give some more mass to handle longer bursts of 40A. Or just go for the quad board.

I really have zero need for 2nd battery.. but I might get a quad board and 2 singles with heatsinks and mess around with it for fun.
 
Last edited:
You must log in or register to reply here.

Similar threads

C
Rebuilding My Gen 1 Hydra Fatty
Replies
13
Views
375
VaiVai
VaiVai
E
Changing BMS
Replies
0
Views
105
Electricmover
E
A
Help me find this Controller
Replies
12
Views
559
aDZ1968
A
C
SPECIALIZED SL battery short circuit - any ideas?
Replies
8
Views
2K
leifg
L
E
Battery has weird values from different sides
Replies
1
Views
370
harryS
harryS
Back