Jetson bolt pro 48 volt controller

[peadar]

It came with 36v controller
want to use 48 volt

 

[lifepo4ever42]

It came with 36v controller
want to use 48 volt

you can buy any 48volt generic brand with 500w power because of the size of the frame but yes its not bolt on so you need to do some soldering

 

[docw009]

He is using the Brainpower controller. It's small but should work well on the Jetsson fine. I have one, but found it to be underpowered for a larger bike.

 

[peadar]

He is using the Brainpower controller. It's small but should work well on the Jetsson fine. I have one, but found it to be underpowered for a larger bike.

thanks for the link, do you want to sell if not using?

 

[DaLanMan]

I have 3 of the jetsons in my garage, waiting for time to play with them, bought em at an auction for 50 bucks each, my son is drooling over them..

Things I need to do are
1) test that they don't go boom
2) get new seat poles and seats (for some unknown reason, not one seat from 4 bikes)
3) get one working let the boy go destroy it.
4) get a 2nd one converted to a better battery and 48v, for his next destruction.
5) figure out why I like lists so much.

I was under the impression that most 36v controllers would handle 48v... I am no e-bike expert, heck I am lucky to get expert status in anything but farting in melody. In this case though I got that impression from reading these forums for like 3 months...

Am I dumber than I thought?

 

[docw009]

The 36V controllers that can handle 48V have 63V electrolytic capacitors in them. The ones that cannot have 50V capacitors. As you know, a fully charged 48V pack is 54.6V,

I own two such 36V controllers. One has only seen 36V. The other one occasionally saw 48V, because I forgot it was only 36V. It's not like it will fail right away, but the capacitors will run hotter and eventually wear out much sooner. possibly within a year.

 

[DaLanMan]

ahh, thank you for the much knowey.

I am a Biochemist by schooling, a soldier by experience and occasionally the person that lets the magic smoke out of the fancy machines... I would love to be more knowledgable on the topic, but I tend to get a wee bit carried away with the doing..

So, since we are talking about my ignorance....

I am trying to figure out what I will need to buy to set up a group of these batteries to run as a group providing 36v.... Because I do have 3 cruddy jetson bikes in the garage I can blow up ::coughs:: I mean improve.

 

[DaLanMan]

oh, and for the record. I now own a trio of Jetsons... I would reccomend against asking the company anything. I am on phase 4 of ordering bits for mine (bought em used) and every thing and I do mean EVERYTHING the support rep has said has been .. .I can't even say useless. It was misleading and has lead to me being on phase 4 of ordering things. They did not even know what parts were on my bike, it feels like they were guessing.

 

[amberwolf]

I was under the impression that most 36v controllers would handle 48v...

Handle, electrically, very likely. But you'd have to check the ratings for all the parts that are connected across the battery bus to be sure of that.

However, there are two things in controllers that may make them not work outside their labelled range, either at all, or for a user's specific needs:

HVC (high voltage cutoff), and LVC (low voltage cutoff), which are used to tell the controller to change it's behavior when the battery is above or below these limits.

LVC is used to tell the controller to shutdown assist when the battery drops below this point, to protect the battery from overdischarge. The BMS in the battery, if it has one, will also have an LVC for this purpose, but it is at a lower voltage that takes the cells much closer to their actual limits, and is harder on them to discharge them to frequently, so the BMS LVC is intended as an emergency shutoff, not an everyday one. The controller LVC is intended for that.

So if you have a controller meant for 36v, it's LVC will be far too low for a 48v battery, and if that 48v battery either has no BMS, or it's BMS fails, there is nothing to stop discharge until it is realy really dead. Since most ebike batteries are not made of matched cells, some of them are going to be lower than others, and may be much lower in aged batteries, or low-quality ones (even when new), and may be overdischarged or even reversed, which creates a fire risk.


HVC can be (but is not always) used to tell the controller not to operate the assist if it's above this limit. If a controller with this is used on a higher voltage battery, it won't operate until the battery is discharged (manually) below the HVC.

It can also be used to tell it not to engage regen braking if it's above the limit, so it doens't damage the battery by overcharging it (because a battery with a separate-port BMS (vs common port) can't stop charging thru the discharge port (regen), no matter how charged or overcharged the cells might be. If a controller with this is used on a higher voltage battery, regen braking won't work, at least not until the battery is discharged far enough to be below this.

There's at least one other thing the HVC could affect but JellyBeanThePerfectlyNormalSchmoo has derailed my train of thought so I'll have to come back to this if I remember it later.