iidisappointment
1 µW
Hi I’m in a bit of a spot here. I have 2 48v batteries but the motor I’m wanting to run is 72v, I have the proper esc. How would I go about turning those batteries into 72v?
2 48v batteries to 72v
- Thread starter iidisappointment
- Start date
If you have the correct controller that can take the 96V, I'd just try the motor at 96V.
iidisappointment
1 µW
I’m very new to this but I think 100amps. I’m using the spintend duel ubox V2 that has an output of 100amps on one esc and 100 on the other, but I plan on only using one side if possible. The motor I’m using is “72v 15000w Big Power Bldc Mid Motor For Electric Tricycle Electric Four Wheelers” From Ali express.
iidisappointment
1 µW
Yeah that’s a bit of my issue at the moment. My VESC only supports 72v up to 80v it’s the spintend dual unbox v2 72v.
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Hi! To power a 72V motor with two 48V batteries, you'll need to connect them in series. This will combine the voltages of the two batteries, giving you the required 72V for the motor. However, ensure that the batteries have the same capacity and are compatible for series connection. Connect the positive terminal of one battery to the negative terminal of the other. The remaining positive and negative terminals will be your 72V output to the ESC. Exercise caution when working with high voltages and refer to the battery and ESC manufacturer guidelines for proper wiring and safety procedures.
How do you propose to reduce the voltage from 96v to 72v in an economically feasible manner?
To reduce the 96V from the two 48V batteries connected in series down to the required 72V for the motor, one economical solution would be to use a buck converter circuit. A buck converter is a DC-DC step-down voltage regulator that takes a higher input voltage and efficiently steps it down to a lower output voltage.
You can find off-the-shelf buck converter modules rated for the appropriate input voltage (96V) and output voltage (72V) and current for your application. These modules typically use a switching regulator design and can achieve high efficiencies of 80-95%.
How much would that cost for a unit that outputs 40A, for example?
Or 100A as the OP is proposing?
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ChatGPT thinks you're talking to ChatGPT. I don't know why its getting so in depth with the responses here, but quoting it is probably giving it what it wants.
chuyskywalker
10 kW
You can't. Well, ok, you can, but it's super risky and will be a pain in the ass. For the spintend controller, you really don't want the battery voltage to be over the 72v nominal max; 84v. A "48v" battery at max charge will be 54.6v. If you fully charge the two batteries and series them together, you're going to be pushing 109.2v into the unit and you will 100% fry the hell out of it.
You could, in theory, only charge each of the two batteries up to about 42v (series for 84) -- but that's half the capacity of the batteries. That's be wildly wasteful.
Here's what you do instead:
- Realize that a motor doesn't (for the most part) give a shit what voltage you run through it. You'll affect the maximum speed and other factors depending on the motor wind, but putting 48v through a "72v" motor is just fine.
- Run the batteries in parallel and turn on field weakening in the controller. With dual batteries you can afford the extra current overhead and you'll get a good way to the speed you'd have on a true 72v battery setup anyway.
£500-1000 in London. But you can buy a Chinese device much cheaper.....
What do you mean?
Link?
Buck-Boost DC-DC Converter 25A/50A/100A
If you are looking for Buck-Boost DC-DC Converter 25A/50A/100A then Battery Megastore have you covered. See all our Buck-Boost DC-DC Converter 25A/50A/100A products here.
www.bmstechnologies.co.uk
Well that certainly reinforces the case for the 96v controller solution in order to save money, weight, and space, as well as being more efficient.Buck-Boost DC-DC Converter 25A/50A/100A
If you are looking for Buck-Boost DC-DC Converter 25A/50A/100A then Battery Megastore have you covered. See all our Buck-Boost DC-DC Converter 25A/50A/100A products here.www.bmstechnologies.co.uk
chuyskywalker
10 kW
Also, if you need >50A you get a fun bit of fan noise to constantly listen to!
edit: hold up -- those only work on 12/24 dc to dc, lol.
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