Added a 2nd integrated battery to my Luna Z1: 48V, (17.5ah) + (17.5ah) = 35ah!

Tom@WashDC

Well-Known Member
Region
USA
City
Loudoun County, VA.
A while back I decided I wanted to carry a 2nd OEM battery to swap when my primary ran low. A new battery costs about $415. I formed a battery cradle to fit at the bottom of the downtube made from solid rubber.

Then I figured that since I had a perfectly good Hailong battery lying around that I wasn't using, maybe I could use the battery pack instead of spending $425. I could install a Battery Balancer ($48) and run both batteries at the same time. So I removed the battery pack from the Hailong case, soldered in a different charging fitting, soldered an XT60 connector for the main power, and wrapped the pack in black Gorilla tape, with a layer of high density foam on the one side of the battery that will rest on the downtube.

Then I installed the Battery Balancer/Connector inside the frame in the motor cavity, running a connecting wire with an XT60 connector to connect the 2nd battery.

Secured the battery with rubberized velcro straps. It works like a charm. I actually have more available power on demand, and 35amp hours! Incredible range.

IMG-5323.jpg
IMG-5321.jpg
IMG-5322.jpg
IMG-5319.jpg

IMG-5317.jpg
IMG-5257.jpg
 

Attachments

  • IMG-5321.jpg
    IMG-5321.jpg
    383.5 KB · Views: 113
  • IMG-5322.jpg
    IMG-5322.jpg
    342.9 KB · Views: 113
I’m guessing the Hailong battery case didn’t fit in the frame for a neater look?
Correct. The Hailong case would hit the upper shock mount. With The bare battery pack I had only 1/2 clearance on the shock mount. I can make a nice case out of Kydex, or use a 3D printer, which I may do in the future. The OEM battery fit perfectly in the cradle, and looked clean, but for now I figured why not use my perfectly good Hailong battery that was going to waste.
 
For sure. I can’t imagine there would be much range on a single 17.5a/h battery with the Ultra motor.

I should receive my Frey Beast next week which comes with a 24.5a/h 60 volt battery. Hopefully it has reasonable range.
 
For sure. I can’t imagine there would be much range on a single 17.5a/h battery with the Ultra motor.

I should receive my Frey Beast next week which comes with a 24.5a/h 60 volt battery. Hopefully it has reasonable range.
For sure, 24.5ah is a huge amount, you will have great range, and you will love it. The 17.5ah was good range if I ride casually with my wife. I could squeeze 35-40 miles on it riding on paved trails. On the other hand when I ride really hard and agressive, 25 miles was my max range. My riding buddy has a Sonders Rockstar with with a 21ah battery which meant I was the one causing our rides to end early. Not anymore.
 
Last edited:
I had a real tough time finding a battery in my tight triangle.
I ended up with this...
I fabricated an aluminum L bracket to bolt to the bottle bolt holes and secured a heat shrink battery and then found a suitable bag to cover and add additional support
If I were you I would shrink wrap the battery as duct tape has too much give, especially in the summer heat to hold things firmly in place.
 
I had a real tough time finding a battery in my tight triangle.
I ended up with this...
I fabricated an aluminum L bracket to bolt to the bottle bolt holes and secured a heat shrink battery and then found a suitable bag to cover and add additional support
If I were you I would shrink wrap the battery as duct tape has too much give, especially in the summer heat to hold things firmly in place.
That's a nice setup, and 10 extra AH is good, that's all I really need for practical purposes. This is just experimental stage. I really wanted to try out a battery balancer rather than fix a swappable OEM battery on the downtube. Now that I've experienced the extra "umph", for certain I will install a nicer, more fitted arrangement. But for now, it's "over the river and through the woods" with miles and miles to go!
 
Last edited:
When I first got into e bikes some years back I started with a BBSHD and a 14ahr battery.
After running out of juice a few times and having to pay the piper for that I decided on making my own.
Found a guy that makes good quality bags that I use for all the battery's I build for myself and friends and they work out really great.

Caring a "spare" in my backpack wasn't really an option as the pack weighs in at like 16lbs with a full bladder and all the shite I bring with me.

And believe me that pack has saved my ass a few times in the outback.

So finding a bike that was conducive to being able to securely carry a larger battery was my first priority.
First thing I did was figure out the LARGEST battery I could fit, which was ironically 34.5ahrs/16lbs ( 10x14 ) .
But after using that battery for a bit and usually coming home with 52v or so I decided to make a smaller one which ended up being 24ahrs/12lbs ( 7x14 ).
I designed it in such a way as to be able to add another group in parallel to give me 27.5ahrs if needed without tearing it apart.

I'm actually thinking of making up a 21ahr battery to save a bit of weight and might go with a 48v pack to save even more weight.

I have always ran a 52v system and it would be nice to have a 48v battery to side by side compare the two.

More range is more important to me than power.

Bike with the smaller battery comes in around 60lbs

Smaller 24ahr pack with my Fox 36.
IMG_2809.jpeg


Larger 34ahr pack with a Wren Inverted fork.
IMG_1099.jpeg
 
Update on my original post up top: Battery connector is working perfectly, and having this much power at my disposal has really been a game changer. Don't know how I lived with a 17.5Ah battery. The connector seems to sip current from both batteries efficiently. I can run this bike a lot harder, for a lot longer. No need to conserve power, and I have plenty of juice on my way back home with no noticeable voltage sag. The rubber coated velcro straps hold the battery with no problem.
35Ah is the way to go!
 
I’m guessing the Hailong battery case didn’t fit in the frame for a neater look?
I had other options which included using the bottle bosses to hold a conventional battery, or a second OEM battery, but I decided that I do not trust the bottle bosses imbedded in the CF frame to be as durable as those in an aluminum frame, especially when I wipe out. I figure the lateral forces may rip the bottle bosses out of the downtube.
 
Update to my Dual Battery Connector Install. See original post of July 7 2023.
The Battery Connector is working flawlessly connected to two 48V, 17.5Ah batteries. I rode it for about 30 miles on the hottest day (98 degrees) this summer and measured the ambient temperature inside the frame right where the unit was positioned. The air temp got up to about 120 degrees after the ride was finished. The CF frame has never felt warm to the touch where the unit is positioned. I have more than enough "juice" when I'm riding, and have never experienced any more voltage sag. I am very pleased with results.

The Gorilla tape wrapped battery resting on the downtube is very secure. I've eliminated two of the velcro straps as there are fewer lateral forces on the battery than I anticipated. The underside foam layer barrier of the battery has molded around the downtube, adding additional grip.
 

Attachments

  • Screenshot 2023-09-18 114904.jpg
    Screenshot 2023-09-18 114904.jpg
    114 KB · Views: 80
General update to my oringal post.
The daul battery connector works just fine. I'm using thinner velcro straps than in my orignal picture to hold the battery in place. The lateral forces on the battery are minimal, so it doesn't take much to keep it tight.

I am spoiled running wth 35Ah, could never go back to anything less.
 
Yep a larger capacity battery makes a world of difference for my riding as well.
Originally had a 34ahr and then a smaller 24ahr battery's that I made with 18650 cells.
Used the smaller one for 80% of my rides and would use the larger one for bigger rides.
Nice having two batterys as when I go camping I can charge up the battery from the previous ride during the time I go on a new ride and it's back up to 100% when I get back never having to wait.

About 6 months ago I built up another 30ahr battery using some 21700 cells.
Performance is similar but the cost is cheaper using the 21700 cells.
Heavier battery per cell but less cells of course.

Gonna be using the 21700's going forward. Better bang for the buck so to speak.
IMG_2856.jpeg

IMG_2859.jpeg

IMG_2861.jpeg
 
Last edited:
Yep a larger capacity battery makes a world of difference for my riding as well.
Originally had a 34ahr and then a smaller 24ahr battery's that I made with 18650 cells.
Used the smaller one for 80% of my rides and would use the larger one for bigger rides.
Nice having two batterys as when I go camping I can charge up the battery from the previous ride during the time I go on a new ride and it's back up to 100% when I get back never having to wait.

About 6 months ago I built up another 30ahr battery using some 21700 cells.
Performance is similar but the cost is cheaper using the 21700 cells.
Heavier battery per cell but less cells of course.

Gonna be using the 21700's going forward. Better bang for the buck so to speak.
View attachment 168382
View attachment 168383
View attachment 168384
Nice, what setup are you using to spot weld? Andcan yo send me your supplier web sites? (Materials, BMS, Cells, Nickle, etc)
When my baterries flake, I will try my hand at building my own.
 
Hey Tomas hope your holidays were good.

The spot welder I use is called Kweld made over in the UK by an engineer guy named Frank Keen if Im not mistaken.
He's got a nice website and explains alot of the details.
Welder works FANTASTIC I have never seen a good weld come loose on any of the packs I have opened up for whatever reason.
Get the plastic housing for the unit and assemble it yourself, easy. total cost is about 2 bills.

I am using a Lipo Battery pack for supply voltage, actually one of the recommended ones on the site.
I get the lipo from HobbyKing and I use the Turnigy Nanotech 5000mahr 3s 65-130c w/xt-90 plug, like 40 bucks or so.

Batterys I use are from either IMR or 18650 Battery Store both out of the US and NEVER have had any issues with my orders. Get the stick -on insulator rings for the Pos terminal to add some extra protection.
18650 cells I used to use were Sanyo GA 3450mahr and 10a discharge. They work great.
Cells I am using now are the 21700 Samsung 50E 5000ahr 9.8a discharge as the price has recently dropped making them cheaper to build a pack by a decent margin.
Less cells but more weight but it's a wash in the end so save some cash for a cold beer instead of a pack, yeah?

The nickel belt material I use is from Al-express .2mm x 64.86mm is the configuration because I hot glue the battery's together slightly offset as to make the packs as small as possible.
No heating issues at all and no they dont break apart.
I'll bet you could spot weld a pack and not even glue them together as they dont move of flex at all when done.
Some belt material is for mounting the battery's side-by-side which is a different config if that makes sense. It goes by center to center spacing. Different sizes for different battery's, 18650 are slightly smaller and shorter than the 21700.You'll figure it out.

The BMS's I get are from our friend E-bay I use the Daly 14s 48v 30a for most 1500w max builds.
If a guy has the higher wattage motor or his motor is capable of being re-flashed for a higher value I will use a 60a BMS so it doesn't have to be modified in the future, they can use the same pack.

Mind you most of my builds are for the G510 Ultra motors which will work with either a 48/52v pack.
Any of the newer BBSHD or BBS02 motors now you have to match the specific controller voltage to the pack.
A 52v pack won't work with a 48v controller motor.

You can re-flash the controller software to make it work I think it's through BIktrix if Im not mistaken but you need a PC and gotta follow a bunch of steps and it's a pain.

Any questions on anything hit me up.
 
Nice, what setup are you using to spot weld? Andcan yo send me your supplier web sites? (Materials, BMS, Cells, Nickle, etc)
When my baterries flake, I will try my hand at building my own.
Quick question... I currently have a 48V 14.5Ah main battery. My bike (Dost Kope) is set up for dual batteries - the main one and one on the drop tube that plugs into the bottom of the down tube. Sadly, Dost went under late last year, and I can get the 2nd pack from a different source, with the correct plug. However, they are big bucks. The 2nd battery offered was a 48v 11.5Ah. So, if I wanted to, could I just purchase a battery that was still a 48V, with a different connector, could I just splice it into the wires that feed the existing plug? Also, If I were to have the OEM 2nd battery it would plug in so both batteries drain as one... so I'm assuming it already has a battery balancer. Let me know what you think, thanks.
 
Quick question... I currently have a 48V 14.5Ah main battery. My bike (Dost Kope) is set up for dual batteries - the main one and one on the drop tube that plugs into the bottom of the down tube. Sadly, Dost went under late last year, and I can get the 2nd pack from a different source, with the correct plug. However, they are big bucks. The 2nd battery offered was a 48v 11.5Ah. So, if I wanted to, could I just purchase a battery that was still a 48V, with a different connector, could I just splice it into the wires that feed the existing plug? Also, If I were to have the OEM 2nd battery it would plug in so both batteries drain as one... so I'm assuming it already has a battery balancer. Let me know what you think, thanks.
I presume they have an internal battery balancer. Of course cannot tell unless I saw documntaiton. You shold be able to splice cables, yes.
 
The BMS's I get are from our friend E-bay I use the Daly 14s 48v 30a for most 1500w max builds.

That BMS makes a lot of sense to me.
Using 14 cell groups instead of 13, reduces the maximum voltage of each cell group from 4.2 1V to 3.91V when charging to 54.6 volts.

There's a small loss of capacity but a big gain in cell life.
 
,.. I hot glue the battery's together slightly offset as to make the packs as small as possible.
No heating issues at all and no they dont break apart.

I was messing around with gluing globes on to LED's and didn't like how the heat of the bulb was enough to melt the glue, so I used silicone,..

Screenshot-2019-10-17-11-28-52.png



Then when I opened up my battery, I bought the "proper" stuff to "glue" it back together.
Regular silicone can damage electronics.
It's kinda expensive but I didn't want to cut any corners when it came to my battery.


20240519_185441.jpg
20240125_164809.jpg



They also have high heat conducting silicone sealant meant for CPU's, but that stuff is even more expensive.


Screenshot_20240519-184852_DuckDuckGo.jpg



I find it rather amusing that it is listed as an LED sealant.
The stuff is white.
If you cover the LED chips with it, you'll seal out dirt and moisture, but you'll also seal in the light. 😂

I've also got conformal gell to coat LED chips, and I was thinking of coating the PCB boards in my battery with it, but @JedidiahStolzfus mentioned that the stuff catches fire easily, so I don't want that inside my battery.

The stuff causes cancer too, but only in California so I figured that I was safe to use it here in Ontario. 😂


20240519_200810.jpg
 
Last edited:
Back