Help with HiKeep K6 L controller replacement

[Krisby]

So I'm pretty new to the whole ebike world, but I have learned enough to where I've decided I want to upgrade my battery from a 48v 15ah to a 52v 25ah, but I'd need to replace my current controller, which only supports up to 48 volts, and because of my inexperience i genuinely am not sure where to look for a controller thatd be best suited for my goal right now, All i know right now is that ideally id want a brushless controller with the capacity of 48v-60v and it comes with an lcd display that actually works with the controller of course, any help would be appreciated

 

[amberwolf]

FWIW, it is very likely your controller will operate just fine on 52v (14s) if it already works on 48v (13s).

The display may not correclty show state of charge SoC, but it will save you a whole lot of work rewiring your whole bike and relearning how it works with the new controller that will probably operate differently and in different ways than the one you have now.

If you *want* it to operate differently, then before you replace anything you should define what you want to be different from what you have now, and then look for controller/display / etc sets that have those features (as well as any feature you already have that you still want).

If none of that matters and you just want to change it out, there are various KT controller/display sets, and LiShui controller/display sets, that are available and with lots of posts about them here on the forum with various bits of info. (even a set of threads on how to replace the original firwmare in some of them with new member-created firmware that does more / different stuff, if you're into that).

 

[Krisby]

FWIW, it is very likely your controller will operate just fine on 52v (14s) if it already works on 48v (13s).

The display may not correclty show state of charge SoC, but it will save you a whole lot of work rewiring your whole bike and relearning how it works with the new controller that will probably operate differently and in different ways than the one you have now.

If you *want* it to operate differently, then before you replace anything you should define what you want to be different from what you have now, and then look for controller/display / etc sets that have those features (as well as any feature you already have that you still want).

If none of that matters and you just want to change it out, there are various KT controller/display sets, and LiShui controller/display sets, that are available and with lots of posts about them here on the forum with various bits of info. (even a set of threads on how to replace the original firwmare in some of them with new member-created firmware that does more / different stuff, if you're into that).

Well, the only reason I want to replace my controller is because on the controller itself, it has no other indication that it can support a battery stronger than 48v, heres an image for ref, From the research I've done, i was told i just needed to buy a controller with matching wires and just plug and go, which is my main goal, I ultimately want to upgrade my battery from my 48v to a 52v or higher so i get more range and power. thank you for the info though

 

[amberwolf]

"48v" is a generic term, not an actual voltage, in regards to controller labels like that. The parts inside are almost always capable of at least 63v, often higher so they would still have some margin even with a 52v pack which charges to 58.8, 4.2v higher than a 48v pack does. The main diference, operationally, is that a controller for a 13s (48v) pack has an LVC that is lower than that usually used for a 14s (52v) pack, and the battery meter on the display would show full longer, and may never show empty, but if the 52v battery is correclty designed and built with a proper BMS it'll protect itself with it's own LVC.***

If you're replacing it anyway, it won't hurt to try the new pack on the old controller, and if it works it saves you money, time, and headaches.

If you prefer to just change it out untried (which is fine), and require that the new controller be labelled to work on 52v, and have all the right connectors, wiring, and functions to be plug-and-play with your old one, you're going to have some research and shopping ahead of you to find that.



Note that even if a new controller has the same connectors, there is no guarantee the wiring inside is the same, and no guarantee that the controller supports the functions your other hardware requires, etc. (or the functions you want it to have).

There are some "standard" connector wirings, for most of the waterproof (julet, higo) plugs, but not every user of those plugs honors the common wiring versions. For the non-waterproof ones, there are a few commonly used patterns, but again, not every place uses those, and not every place uses the same wire color to mean the same thing (not even red for positive power and black for ground is always honored, which has resulted in various blown up electronics).

One common example: If the new controller doens't have an autolearn function for your motor's hall and phase wire combination, and it's motor cable is wired differently than your present one, you'll have to (depending on whether you have molded or open connectors) depin the connector or cut open the cable on your motor or your new controller to experiment and find the right combo, and then repin the connector or splice the wires back together in that order.

So, you have to ensure it's not only the same connectors, but the same wiring order, whcih is difficult to do unless you find the same controller brand/model (and even then..no guarantees).


Functionally, it depends on what's on the bike already, and how it works for you, whether a new one will work the same. Some controllers have soft-start, so they ramp up slowly when you start using throttle or pedal control. Some start instantly to the level you're commanding. Some have fewer assist levels than ohters. Some have throttle always overriding pedals, some don't. Some have complex and more usful ways the PAS operates, some just go full speed at the chosen assist level if you pedal at all. Some require a different PAS signal than others, or a different throttle voltage range. Etc.




***Because it's harder on a battery to run it down to it's safety cutoff LVC, rather than letting the controller protect at a higher level, it's a good idea to test out where that cutoff really is, and then mark your display or note the point at which this happens, and don't ride down to that point regularly.

 

[amberwolf]

I ultimately want to upgrade my battery from my 48v to a 52v or higher so i get more range and power.

If you want more power, you'll need a controller that can provide that, assumign your motor is capable of using it without overheating.

To get that, the controller has to draw more current from the battery. Your presnet controller is a 21A type, per the image you've provided (copied below for reference so it shows up in the thread directly without downloading it). Power is watts, which is volts x amps. So you need to figure out how much more power you want (watts), then find a controller wiht a current limit that can do that at the voltage you're going to use.

Increasing the voltage also increases the possible motor speed (not necessarily the bike speed, that depends on a bunch of things).

But you can get more power and more range without changing the battery voltage. Just use a battery capable of the current the controller requires to provide that power to the motor.

For range, you need more Wh (watt-hours), whcih is Volts x Ah (amp-hours), so just using a 48v pack with more Ah than the one you have now would do that. Or you can just get a spare battery the same as you have now and swap them out when the first one gets closer to empty. Or even parallel them to run at the same time; there are considerations for that, but it's possible, and would double not just hte capacity, but the current-delivery-capability (with some caveats).




Most motors can take *some* more power than their markings suggest, depending on a bunch of other things. At least in short infrequent bursts, many can take twice as much power as they're "rated" for. Geared hubmotors (vs DD direct drive) are more sensitive to extra power, because they overheat faster but also because they can actually break the clutch or gears inside from it. What yours can take you'd have to experiment with to find out (this is sometimes a destructive test, however).

Note that getting more power out of a systme requires it to be loaded down enough to require that power in the first place, so while you can put together a system capable of higher power (even in the tens of kilowatts), if your riding conditions don't require this much power, your system will never provide it.


So if you have a specific requirement for amount of power based on your riding conditions/etc., you can build a system around that. Otherwise, you probably should find out how much power it takes to do the job you want the system to do for you, which can be done in various calculators / simulators like the ebikes.ca trip simulator, etc.


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