2021 icon i40 with Roy pow lithium battery locks up

[Kong]

So glad I read this. I was almost ready to pull the trigger on a new Roy Pow lithium battery. I will not be doing that until there is resolution to this issue.

[fixed4life]

Well, here is my progress. Just finished buttoning everything back up. So far seems to function as designed. I have not yet done any high speed testing, but I have a testing methodology in mind, I just need my helmet and a few hours of time, and I am all out of time for the day.

Cheers!

Wide shot


A few closeups



Blurry close-up of EMB connection


Main battery harness


EMB supplemental harness

[Pat911]

Originally Posted by fixed4life

... I just need my helmet and a few hours of time...

[ATrain]

Originally Posted by fixed4life

Well, here is my progress. Just finished buttoning everything back up. So far seems to function as designed. I have not yet done any high speed testing, but I have a testing methodology in mind, I just need my helmet and a few hours of time, and I am all out of time for the day.

Cheers!

Wide shot


A few closeups



Blurry close-up of EMB connection


Main battery harness


EMB supplemental harness

Very strange, but your image links don't work? I was just quote-replying to you and noticed you had IMG tags, but no pics. I fixed them for you. Can you explain more what we're seeing? This look like an AUX battery, but with a whole lot more going on? Are those extra components just the BMS and other things you've taken out of an e-bike or something? Or what is everything?




What I noticed, but haven't confirmed, is I think the EMB actually on an automotive relay already. Meaning most race-condition considerations you would be dealing with would be up against another relay.

I haven't had time to play with any circuits really, and since I don't have lithium it's not really a high priority for me, but what I planned on doing was experimenting with diode logic gates to bypass that concern...essentially saying if power comes from either the lithium pack OR the aux battery, keep the relay open. It could be pretty simple...just wiring a few diodes together and then hooking to the keyswitch.

The cart having 1 relay to control the EMB means that could be a failure point causing a dangerous lockup maybe? Relays don't frequently fail, and if it failed...I think it would be on initial cart start-up, meaning the brake just wouldn't release. I don't think it's typical for a relay to fail while open...so probably a low concern.

[AdamP]

FYI Icon calipers at least on my 2021 I40FL do have a arm that part of the caliper which has the capability of attaching a mechanical hand brake. I’ve seen on other carts they use a handbrake similar to a cars handbrake like old school stick shift cars. They can be mounted between were the driver and passenger sit on the seat box. They also mount them below rhe dashboard.
The obvious place would be between the driver and passenger. My golf cart dealer whom I’m friends with builds custom carts also and probably has 20 carts laying around that are bare frames. I’m going to see what I can come up with

[hoog0726]

Cool idea. I can't post links yet but there's an auto switch on amazon that I've been looking at, just search for:

DC Power Switch Module, 12V 24V 36V 48V 10A Battery Power Source Controller Automatic Switch Emergency Battery Change

[fixed4life]

Originally Posted by ATrain

Very strange, but your image links don't work? I was just quote-replying to you and noticed you had IMG tags, but no pics. I fixed them for you. Can you explain more what we're seeing? This look like an AUX battery, but with a whole lot more going on? Are those extra components just the BMS and other things you've taken out of an e-bike or something? Or what is everything?

What I noticed, but haven't confirmed, is I think the EMB actually on an automotive relay already. Meaning most race-condition considerations you would be dealing with would be up against another relay.

I haven't had time to play with any circuits really, and since I don't have lithium it's not really a high priority for me, but what I planned on doing was experimenting with diode logic gates to bypass that concern...essentially saying if power comes from either the lithium pack OR the aux battery, keep the relay open. It could be pretty simple...just wiring a few diodes together and then hooking to the keyswitch.

The cart having 1 relay to control the EMB means that could be a failure point causing a dangerous lockup maybe? Relays don't frequently fail, and if it failed...I think it would be on initial cart start-up, meaning the brake just wouldn't release. I don't think it's typical for a relay to fail while open...so probably a low concern.

Well, after our back and fourth earlier in this thread, I realized that prioritizing simplicity and ease of installation would create something that might actually be useful to folks. The goal was only 2 connections that any owner can make, one to the battery (just the regular post BMS lugs) with ring terminals and the other to simply plug inline with the EMB connection behind the back cover. So far, it has met all of my expectations in that area and works well at driveway speed (more testing to come).

Essentially it is a spare battery, that is charged by the main battery (from 25-80% for longevity since it will be so low use) that is triggered to power the EMB for 30 seconds if power from the main battery is lost. I have built in a test button for monthly functionality testing and a buzzer that sounds when the device is activated or if the devices battery is out of spec. Also adding a keyed switch that functions as a service override (to prevent it from releasing the EMB) to be engaged before intended battery maintenance. Like I said, the focus is on simplicity, all self contained, no additional wiring in or additional complexities. Calling it CartUPS when I talk to my wife about it, and I think that pretty much sums it up...

The box itself is a total mess ATM but it is a prototype, so... I am actually still waiting on several bits but I just went ahead and started with what I had lying around, so dont judge it by its looks at this point. I also revised several things this weekend and ordered the appropriate bits today. In the next week or two I should have something in there that doesn't look quite so terrible. And yes, that is a hoverboard battery.

[fixed4life]

Tested @ ~35mph, took a lot of nerve, but turns out it works just as it did in the driveway. Have been working on minimizing current draw more than anything over the past week. I now have it down to 3ma from the cart and 20ma from the onboard device battery (idle). Have a few more bits on the way that will hopefully get the onboard battery current down below 10ma at idle and be more efficient while charging (those clunky 40A automotive style relays were all I had to use until my new charge controller comes in and I can use low voltage relays for that job).

[robertmII]

Really cool that you've got this working! How did you hard shut off power at 35 mph? I bet that did take some nerve to try the first time.

[fixed4life]

Originally Posted by robertmII

Really cool that you've got this working! How did you hard shut off power at 35 mph? I bet that did take some nerve to try the first time.

Thanks! Yes, it really was scary, even though logic dictated that it should be the same as in the driveway. There is something about the high stakes stuff that scares the heck out of me.

For testing, I actually already had the solution in place in the form of a "security system" (low security, but still some) relay system I built when I first got the cart. Essentially, I ran the 48v positive from the supply side of the run/tow switch to a relay controlled by a wireless transmitter. That way, when the cart is "turned off" (from my garage door / cart fob), it is essentially immobilized as the run/tow switch will not disengage the EMB. In the reverse, pulling the power to this switch will engage the EMB at any point or speed you hit the button, so all I had to do is switch the supply side of "CartUPS" to that circuit (after the relay) and boom, scary death machine on tap...