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Razor Dune Buggy mod to 48V/1000W/Lithium

So my son is interested in supercharging our Razor Dune Buggy as a precursor to more advanced eleciric vehicle experimentation. I'm pretty comfortable with electricity/power basics. With the exception that here on these forums I've seen reference to hall-effect throttles whereas other motor controllers simply use a potentiometer to supply a control voltage. So, my understanding... Make sure the controller, motor, and batteries are at the same voltage. Make sure that the controller is equal to or more than the wattage of the motor. Make sure that the batteries are equal to or more than the wattage of the controller. The wrinkle comes with Lithium. First off, I'm not comfortable buying a 48V litthium pack without a matching charger, as the charging curve has to be correct or you risk damaging the batteries or a fire. Secondly, unlike SLA, I'm getting the impression that amp-hours are greatly affected by current draw in lithium. I.e., a pack rated for 15AH at a 3A "nominal discharge" will not last as long if you pull its "maximum continuous discharge" of 15A (I.e., running the dune buggy at full throttle all the time). And by "not last as long" I don't mean the obvious conclusion that the batteries run longer at 3A vs 15A, it's that you won't get a full hour at 15A whereas you might get 5 hours at 3A. There's lots of 16550-based battery packs out there, but before I lay down several hundred dollars, I want to make sure I know that it's going to give us the capacity we are looking for and not run into other unforeseen issues. Any thoughts? This site looks awesome both in terms of inventory and expertise, perhaps with the small exception that it's a bit light on the selection of lithium options.
Apologies for the run-on paragraph. Didn't know that line terminators get stripped out. Do I just need to embed HTML tags like paragraph markers?

Since this forum is externally sourced I do not know too much about the coding of it so I am unsure if HTML tags can be embedded. I will run some test on that later to see, but for now I will focus on your other questions.


My thoughts regarding Lithium battery capacity at high current draw rates are that the high draw capacity would be specific to the brand of battery, and to try to obtain specifications from the battery's distributor regarding its capacity at a certain continuous Amp draw. Without these specifications it would be a guessing game of how they would perform under a certain load. I would not expect these type of specifications to be available however it never hurts to ask anyways.


All battery chemistries that I know of have a lower capacity as the current draw increases. That just seems to be the nature of batteries. I know some battery chemistries are better at this than others though.


Our selection of Lithium batteries is limited because we are wary of unproven brands that may not be trustworthy. We only sell Lithium batteries that are distributed by companies based in the USA who will take responsibility for them if they malfunction and catch fire. If you are concerned about the safety of Lithium batteries then we recommend to only purchase them from companies based in the USA who have been in business for several years and are well established. If Lithium batteries are purchased from outside of the United States then the company that sold them has no liability to repair or replace property that was damaged by the batteries if they malfunction.


It sounds like you are well aware that the maximum Amp rating of the controller needs to be the same or less than the maximum continuous discharge Amp rating of the Lithium battery, However I thought I should mention that in case anyone else reading this does not know.


Please let us know if you have any questions.

Thanks for the quick reply. I'm getting the sense that a lot of the battery packs have BMS boards in them which both regulate charging and protect from too high a discharge current. But like everything, it's all vague. Still a bit confuse about what's involved with a hall-effect throttle vs a throttle which is essentially a mechanical coupling to a potentiometer. Some of the motor controllers I've seen show throttle harnesses with +5V, GND, and Control wires, which would correspond to each end of the potentiometer then the wiper, respectively. Any insight as to what's involved with the hall-effect throttles you sell (or references I can read)?
The definition of a BMS (battery management system) board is as you mentioned vague. BMS boards may or may not protect against over-current, over-temperature, over-charging, etc. The manufacturer would need to specify what it does in order to know. I like to presume that the BMS board will not protect against over-current and use a controller that has a current limit which is the same or less than the rated maximum continuous current draw of the battery, just to be safe.

Electric scooter, go kart, and bike hall effect throttle take a +5 Volt DC input Voltage and output a +0.8 through +4.2 Volt DC signal Voltage.

A potentiometer will basically do the same thing except it will output 0 through 5 Volts instead of 0.8 through 4.2 Volts. This will work with speed controllers designed for hall effect throttles because the controller will only react in the 1 through 4 Volt throttle signal range. The far left and far right adjustment areas of the potentiometer will not control the motor due to this, and only the central adjustment area of the potentiometer will control the motor's speed.

Potentiometer contacts can get dirty, corrode, and wear out, as opposed to a hall effect sensor which is a hermetically sealed IC chip and a magnet which does not physically contact it. So the hall effect throttle is not prone to wearing out or providing an incorrect or inconsistent throttle position signal to the controller like a potentiometer possibly could.
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