In the conditions of the pandemic, the means of individual mobility are becoming increasingly relevant, among which — monocoles. And although they are significantly less than electric bikes and electrical scams, they find their consumers, including in the Russian market.
But often, by purchasing an inexpensive package and starting to ride, the buyer understands that the capacity of the established battery is not enough. He has a natural desire to increase it, having received the increase in the turn of the stroke.
Today I will talk about making an additional battery for monocoles, and I will try to highlight the whole process as much as possible. Perhaps someone will come in handy, or it will just be interesting to see. So let’s go!
We put mono-salts on the stool and unscrew the left (along the movement) side cover.
The inner world of the apparatus appears before us, with its standard battery. It will have to be replaced with a new, increased tank, which we will collect.
The native battery on the rated voltage 74 V, the maximum voltage in the charged state — 84 V. The absolute container is 650 VTC, it means each of the 20 blocks includes 3 cells, a capacity of 3 Ah, that is, the battery is collected according to the 20S3P scheme.
The new battery will be assembled according to the 20S4P scheme, that is, the capacity will increase by 33%, from 9 Ah to 12 Ah, the absolute container will be 864 VTC.
Before starting gluing cells, it is necessary to understand how the batteries blocks inside the available monocole space will be located.
Removing the necessary sizes, draw a battery circuit, which includes 2 modules: the main from above, containing 15 blocks, and an additional bottom containing 5 blocks.
Now you can go to the assembly. We have in stock there are 80 lithium-ion cells of the Samsung InR18650 with a capacity of 3000 mAh and internal resistance of 20 MΩ.
For the convenience of the gluing, a template for 10 cells was used, but you can do without it, if you lay the cells on the plane and dripped with a superclouche on the joint, and then glue the resulting rows among themselves.
The connection of the cells will be performed using spot welding. I was fortunate enough to have access to the factory version of the welding machine, but if you wish, you can either rent, or order an inexpensive alternative on Aliexpress, which is quite suitable for similar small projects.
For connecting cells, we will use a nickel-plated tape, which is also available on the Chinese trading platform. Cut the required number of contacts.
Before welding, degrease the contacts, and in the process, we will definitely use safety glasses to protect your eyes from possible sparks.
Cell blocks are welded in accordance with the scheme. Far-Five Blocks — for the main module, close two — for additional.
Balancing wires can be affected directly to contacts, and you can welcome additional conclusions. I chose the second option. And for the convenience of further installation numbered the conclusions.
Manage our battery will be the BMS (Battery Management System), which ensures that all blocks are the same voltages. In our case, BMS for monocoles differs from those BMS, which are used in the batteries of electrobic.
The difference is that this BMS turns off the battery when charging is complete, but does not disconnect when discharge. It is necessary so that the monofilament does not turn off during the movement and the driver did not fall. The monocoles controller will be informed by the user that the battery is almost discharged and the recharging is required, including using audio signals.
Return to the assembly. At the ends of the blocks glue insulators, cut from a sentoflex. We pretend the location of the BMS card.
We prepare the power wires. For charging, I chose a multicore wire with a cross section of 1.5 kV. mm, for discharge — 2.5 square meters. mm. On the wires we put in the glassized tubes of a suitable diameter. Charging connector — XT30, discharge — XT60.
We complete the insulation of the Sintoflex, we connect everything in places, and before connecting balancing connections, check the voltage on each pair of contacts.
And then pack each of the modules into the heat shrink tube of suitable size using a technical hair dryer.
It remains to place the battery in the monocole housing. Retractable handle The owner of the device removed so that it does not interfere with the bottom module. He actually did not use it, because he kept mono-salts for special belts attached to the top handle.
And so the device with the reverse (right) side looks like. This battery consists of three modules, and was collected a little earlier. In the initial version, on this side there was no battery at all.
Before connecting batteries, we definitely charge them in turn to one voltage. When everything is ready, set the side covers in place.
So, when buying a monocoles in it stood a standard battery with 650 VTCH, which, according to the owner, had enough about 35 km. Then, the battery was added on the right side of 1080 VTC, that is, the total was 1730 VTC, which had already become 80 km.
And the last iteration on the left side, the native battery was replaced by an 864 VCh battery, that is, the total capacity was 1080 + 864 = 1944 VTH, and therefore the stroke reserve should increase to 90-100 km.
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