Help request for modifying a motorized cooler

[kmxtornado]

So we know what we're dealing with:

More photos on Instagram @ricecooler and also in the photo thread here: http://www.endless-sphere.com/forums/viewtopic.php?f=12&t=70650

Actually, it's just the amp hours rating of battery that I need a recommendation on. 10ah vs 15ah for my application.

I bought a Cruzin Cooler and for those that don't know what it is, it's basically an ice chest with a motor. I use it as my stroller with my daughter. Benefit of being able to ride and store gear (diapers, milk, clothes, etc) in the cooler compartment. IG @ricecooler if your'e interested. Lots of fun until the controller and possibly other components fried yesterday. Time for new components if the manufacturer doesn't cover any replacements under warranty. This might be my opportunity in disguise to upgrade

PRIORITIES:
Goal is to bump up the speed through overvolting but to do it safely. Torque for slopes is more the priority though. I'm okay replacing motors every now and then. They aren't that pricy and the swap is fairly easy. I just don't want to be replacing controllers and reconnecting those wires all that often. Getting stranded that one time wasn't an experience I'm looking forward to again.
A. Maintain descent range
B. Torque for slopes. Not hills, just minor inclines of uneven ground. This thing stock is weak. It can barely go up a driveway.

CURRENT SETUP:
24v 18ah from two 12v 18ah Lead Acid batteries that currently fit into a nice clean battery box to power a 500w motor. Tops out at 13mph.

NEW SETUP:
This is where I am looking for expert advice from you folks. I gave up on the idea of reusing my 36v 10ah (I think) LiFePo battery from my previous projects. I figure I'd want to run both ebike or escooter and this new cooler at the same time to ride with friends. Also the battery has been rebuilt since it was bulging and I don't really want to put too much stress on it. I'll just stick with the cheap lead acid batteries for the cooler.

I'll of course be getting a new 36v controller to handle the new voltage going into the system and throttle too. There is a company out there that specializes in modifying these with an overvolting kit (excluding the required extra battery). I don't doubt the claim of reaching speeds of 23mph or at least 20mph, but wondering what batteries to get as far as amperage is concerned.

QUESTIONS:
1. I'd like to keep the same physical volume of the batteries so that it fits in the battery box nicely. Necessary b/c it's heavy and hauling that in and out of the trunk separately from the cooler itself is much easier on my back. This limits me to 12v 15ah batteries tops. 12v 10ah batteries are also a consideration. 12v 20ah batteries of course exist, but 3 of them for a 36v setup wouldn't fit in my stock battery box which is a requirement for me. Do I go with 12v 15ah batteries or 12v 10ah batteries? 10ah I understand will have less range, but perhaps also less stress on an overvolted system and therefore less likelihood of burning anything out, correct? Does amperage affect torque I would need for slopes? When I'm stalking slopes, I'm talking minor change or grade, but of course any improvement would be awesome. I'm not expecting to build some amazing monster out of nothing but if i could take on San Francisco hills that would be a dream come true.

2. How much range am I sacrificing generally by going from 24v 18ah battery pack to 36v 10ah battery pack with all else being the same and the extra weight of a third battery being negligible for simplicity? I go to street fairs and car shows on this thing and would like it to last 4-6 hours going 3-5mph 95% of the time but have the capability of showing off a bit at 20mph in 5 second spurts.

3. The wires connecting the controller to my motor melted big time. Should I be worried about a dead motor or is it just the controller that needs replacement?

THANKS IN ADVANCE TO ALL THOSE THAT REPLY. I really appreciate your help greatly. Hoping to get my daughter and me back on the road again to take more photos for you guys. I'm no expert in electronics but am eager to learn.

 

[Nobuo]

Hi, very interesting project, I really want to see some pictures

1 - With the 36V controller and 36V battery setup you will reach with your 500W motor close to 20mph fully charged (from what you are getting now with 24V). No chance to be really over-volting the motor, and that would be not depending on the Ah, just the nominal voltage of the battery and battery max voltage fully charged (~42V on 36V battery packs). More Ah won't be more harming, the important is that the controller is made to work with 36V batteries, motor is inside the safe range. 15Ah or 10Ah won't neither going to burn anything, indeed with 15Ah you would get less stressed and more efficient battery discharging rates. (BMS has an impact in limiting max amps discharge rates, but I dont't know if you will use one)

The amperage could be slightly higher on slopes (voltage drop will be lower) with the 15Ah battery (but almost sure it will be the same limited by the BMS if both batteries use one). the biggest difference will be less heat and less voltage drop on hard hills with more Ah pack.

2 - The differences are 423Wh vs 360Wh, But because max speed will be higher in 36V setup, practical range would be near the 40% more on the 24V 18Ah battery. Weight won't have significant impact.

3 - How were the conditions that made the wires burning? BMS built-in batteries? where the wires melt? batteries had anything to limit the max amps output?


One question from my side: Did you thought about getting a lithium-ion battery? You could get until x3 the energy in the same volume you have now.

 

[kmxtornado]

Thanks for your responses. You seem quite knowledgable about this stuff. I read your reply over a couple times and still trying to digest it in my little brain.


1. The manufacturer claims 23mph from the stock 13mph which I did accurately clock in at using my current 24v system. I don't expect any product to fully meet advertised numbers, so 20mph would be sufficient and still worth the work/money put into it. Good to hear that your estimates align with this. The upgraded controller definitely is designed for a 36v system. It's a full replacement of my current 24v controller. If higher ah battery = less heat, then I guess I'm expecting MORE heat since I'm going from a 18ah battery to a 15ah one. I suppose this is still the case despite the ride bumping up to an additional battery. Two 24v 18ah batteries vs 36v 15ah batteries. Or is it the total ah of all batteries 15+15+15 > 18+18? I suspect the math doesn't work that way. Layman talking. Sorry for my ignorance. Trying to learn still.

2. Although the max speed would be higher on the new 36v system, I don't plan on maxing it out to that much that often. This motorized ice chest is literally used for street fairs, festivals, car shows, farmers markets where the environment is congested with pedestrians which limits my speed. The high speed is for passing crowds to get to open areas and would be in spurts of literally seconds. It's more torque I'm interested in gaining but not sure if this mod of changing from 24v to 36v would increase it that drastically and if so, not sure if it would create even more heat output and possibly burn out my wires yet again under less demanding conditions. Comments regarding that?

3. I do not have a BMS on the batteries. I didn't realize that was available for Lead Acid batteries. If you have info or a resource on where I can learn more about it other than just googling, I'd be excited to put my head into it. The wires that burnt were the ones connecting from the motor to the controller. The conditions I was in wasn't that demanding. I was not at full throttle and was at minimal slope, not even the slope you'd expect from a low slope driveway. Percentage slope has to be way less than perhaps 5%. The cooler does horribly on slopes. Literally, the curve of most streets angling down at the sides to drain water appears flat to most people when you're not paying much attention. Even that tiny grade change of what I understand to be about 2.5% makes the ice chest hesitate. A bit saddening to have experienced that being that crossing the street is obviously something I want to do on a regular bases w/o having to put my foot down and push my way as people are eyeing my weird contraption.

4. As for a LiFePo battery. I do have one. It's a 36v 10ah battery from what I remember. I use it on the small foldable scooter you see in my avatar to the right of this message. I want to be able to ride both at the same time (riding with friends), so wasn't so excited about reusing it for this ice chest cooler project. Also the batteries are quite expensive. Being that the cooler was priced at $629 (now available under $570 since I bought before the sale, oops), paying $400+ for a battery to run it isn't quite something I'm ready to do. I'm okay with the SLA batteries since it's a heavy ride anyway and batteries are housed in a container that I load in and out of the car separately anyway.

 

[Nobuo]

1- The heat that come from the battery, if it is correctly built inside, comes exclusively from the cells. So each cell has a máx amps capability, and also a cell work better as less amperage is demanded. For same voltage and different capacities on a battery (Ah) depends on how much cells are paralleled. So the more cells paralleled, the total amp is more divided between the cells, so each cell work more efficiently (less heat, more power for the motor).

When you go from 18ah battery to a 15ah one, you must expect more heat (slightly), if (appart from the same battery chemistry) the controller is exactly the same (max amps and same voltage), so the máx current continuos and peak consumption is the same.

So is not like "15+15+15 > 18+18" because each battery is 12V so when you connect them in series for the 36V 15Ah, or 24V 18Ah, the current doesn't sum from one battery to another, is voltage what sum. so if one of that 12V batteries is capable of 30A máx (for example) a 36V battery made with 3 12V ones, will have the same 30A max at 36V.


2- The máx speed will be considerable increased from 24V to 36V.

The power is the same for the same speed independently from the battery/controller Voltage. Because you use the same motor, in same terrain at the same stable speed, despite the voltage you use, you will use the same power on the motor (W).

So if the controller has the same amps output, you will have increased torque also, that because when you push the throttle to the max, you are feeding the motor with more power. For example 24V * 10A = 240W of power to the motor. 36V * 10A = 360W. The heat will be increased on the motor, of course, because is strictly proportional to the amount of Watts is fed with.

Wires also are susceptible of heat and harming only by amps, not voltage. So if you push the same amps or less through the wires, the effect will be the same.


3- BMS is needed when you charge batteries in series at once. for example 3 series of your 12V batteries charged always at once with a 36V charger need a BMS, or over time will be differences in SOC (state of charge) for each battery. If you charge to full each 12V battery separately with each 12V charger, and then connecting to use, you don't need a BMS.

The wires burnt was probably because the controller was feeding to much amps to the motor, and it has very thing wires for such amperage. High continuous amps for a wire makes heat that accumulates on the wire until burnt it. If you take a picture of the motor and wiring we can estimate it.


4- between LiFePo4 and SLA is not very much differences in energy density, yes between efficiency and voltage drop, (LiFePo4 is very stable with voltage output). Lithium-ion chemistry is half the weight and 1/3 of the volume for the same energy than LiFePo4.

for a 36V 10Ah lithium-ion battery with high quality cells, you should pay around $300 with charger included. The same with LiFePo4 around $280.

If the battery include some aluminium case add 40$ more

 

[kmxtornado]

1 - Thanks for the info. I understand now. I figured I was wrong about the 15 + 15 + 15 thing. Glad you clarified that. You mentioned I can expect more heat if all else is kept the same except the battery. I am upgrading the controller from a 24v one to a 36v one which I understand is recommended and practically a must for overvolting. So would I still expect the same amount of heat as before when I push the cooler with the same Power output?

In other words, if I put a speed controller on the cooler and cap it off at 13mph on the new 36v setup, it would produce no more heat that when I maxed it out at 24v, correct?

2 - I am expecting more heat to the motor at higher speeds and do understand that I am stressing it out beyond what it normally is designed for and therefore will die off sooner. I'm okay with that. The 500w motor for the cooler is about $100 which isn't a big deal in the big scheme of things and that I'm assuming should last awhile being that I don't ride the cooler that fast for that long and only use it a couple times a week at city events. Good experience with my overvolted mini e-scoot also gives me the confidence that this will be alright. Furthermore, you seemed to be confident in the motor life as well. Support from the experts is always a good thing.

Work network doesn't allow me to access photo sites to upload the photos here. I'll have to do that later. It's the two wires coming from the controller going into the single motor wire that melted big time.

3 - I found out that indeed the batteries are hooked up in series (not parallel). Had to look that one up and watch videos for my own education. Regarding a BMS. It sounds like you recommend one since I won't be charging each of the 12v batteries separately. I'm at work right now, but I'll be reading up on this: http://endless-sphere.com/forums/viewtopic.php?f=14&t=8074 Any other sources you recommend for figuring out where to buy a BMS for my soon-to-be three 12v 15ah setup? Or perhaps you already know of one off hand and can give me pointers on how to install it? I'm happy to research soldering and whatever skills necessary. Just need the basics of a wiring diagram to know what plugs into where, etc.

4 - Not enough amps for range I feel for a 36v 10ah battery. I'm okay with the SLA's. The case I have can be bought separately and fits snug. It's proprietary to the cooler since it fits perfectly. Yes, it's also priced in the $40 range. I think $48, but around there.

5 - Preventing melting. This is obviously the biggest thing since I've already experienced this. I'm reading up on Cycle Analyst computer to help limit the amps drawn when going up slopes. Still reading. I know it's the best apparently. Pricy though at $170. Wondering what alternatives there are. Not looking to break the bank. Not looking to have a $1,000 ice chest. And since this is technically a scooter, there's no advantage of the pedal assist readout feature of the newest V3 model. Perhaps there's something more geared towards my needs at a much lower price.

This is the specs for the 500w motor that I have: http://unitemotor.com/en/productmin.htm. Not sure how to make sense of all that.
"full load current" looks important.
Am I understanding correctly that the rating of 24v/36v/48v means that I could technically run 48v through this w/o frying the motor? If that's the case, then I have nothing to worry about as far as putting only 36v through it, correct?

You mentioned you wanted to see photos. They're mostly all on Instagram. I believe you can access it through the web too. IG @ricecooler. The initial ones are uploaded on e-bike blog in my signature.

 

[mark5]

Cruzin Cooler Wiring Diagrams:
http://www.cruzincooler.com/service/technical-diagrams/

 

[kmxtornado]

I thought I knew that website inside and out. Apparently not. Thanks for showing me this. Looks like I have some homework to do.

 

[mark5]

If you have 3 SLA batteries you can make blocks of Anderson Powerpole connectors to easily connect them either in parallel for charging or in series to power the controller. Then you won't need a BMS. You can crimp the contacts to the wires and don't have to solder. See here:

Parallel Charging Wire Harness w/Pics
http://www.modifiedelectricscooters.com/forum/topic.asp?TOPIC_ID=947

Anderson PP tips without the fancy crimp tool.. by Ypedal
http://endless-sphere.com/forums/viewtopic.php?f=14&t=2742

 

[kmxtornado]

For overvolting, I had to connect the batteries in series to up the voltage while keeping the amperage the same. As I understand it, connecting it parallel would maintain the 12v capacity even for all three batteries but would triple the amperage 15x3 = 45ah.

UPDATE:
So it turns out the motor is not toast. It was only the controller (and associated melted connectors) that need replacing.
A company that upgrades these coolers has mentioned on his website that it's typical to experience melting connectors on the cruzin cooler product. As a solution, he recommends doing a butt connection for the wires connecting from the controller to the motor and also to the battery. That'll be a project for this week as I hadn't done that in my overvolting this past Saturday.

 

[Nobuo]

1 - Thanks for the info. I understand now. I figured I was wrong about the 15 + 15 + 15 thing. Glad you clarified that. You mentioned I can expect more heat if all else is kept the same except the battery. I am upgrading the controller from a 24v one to a 36v one which I understand is recommended and practically a must for overvolting. So would I still expect the same amount of heat as before when I push the cooler with the same Power output?

In other words, if I put a speed controller on the cooler and cap it off at 13mph on the new 36v setup, it would produce no more heat that when I maxed it out at 24v, correct?

Of course, 36V controller is a must for "overvolting" your current motor. If the power output you push is the same on both configurations, You will push less Amps on the 36V battery than on the 24V one, because Watts = Volts * Amps. So the battery will work more efficient and fresh, but this is only if both batteries 24V and 36V would have the same Ah (capacity). A battery work more fresh as less amps is required continuously, or as more capacity it has, so it can share the amps requirements between more cells. On the other hand the motor will produce a heat directly proportional to Watts input.

2 - I am expecting more heat to the motor at higher speeds and do understand that I am stressing it out beyond what it normally is designed for and therefore will die off sooner. I'm okay with that. The 500w motor for the cooler is about $100 which isn't a big deal in the big scheme of things and that I'm assuming should last awhile being that I don't ride the cooler that fast for that long and only use it a couple times a week at city events. Good experience with my overvolted mini e-scoot also gives me the confidence that this will be alright. Furthermore, you seemed to be confident in the motor life as well. Support from the experts is always a good thing.

Work network doesn't allow me to access photo sites to upload the photos here. I'll have to do that later. It's the two wires coming from the controller going into the single motor wire that melted big time.

The point where they melt is the key. You should indicate if you have access to the motor to have the chance to exchange those wires for a thicker ones.

3 - I found out that indeed the batteries are hooked up in series (not parallel). Had to look that one up and watch videos for my own education. Regarding a BMS. It sounds like you recommend one since I won't be charging each of the 12v batteries separately. I'm at work right now, but I'll be reading up on this: http://endless-sphere.com/forums/viewtopic.php?f=14&t=8074 Any other sources you recommend for figuring out where to buy a BMS for my soon-to-be three 12v 15ah setup? Or perhaps you already know of one off hand and can give me pointers on how to install it? I'm happy to research soldering and whatever skills necessary. Just need the basics of a wiring diagram to know what plugs into where, etc.

I start from the point that your SLA setup is really a cost saver, so I think we should be working on that line. For SLA batteries I really recommend to you to forget about install them a BMS and just make 12V charging each one separately, or paralleling them when charging. In this way the charge will be balanced and no more costs added.
As Mark5 shared, about Parallel Charging Wire Harness. Is a reliable choice.

http://www.modifiedelectricscooters.com/forum/topic.asp?TOPIC_ID=947

That would be the best way, but you could even do it easier with alligator connectors, as you will use the scooter on spare days.

4 - Not enough amps for range I feel for a 36v 10ah battery. I'm okay with the SLA's. The case I have can be bought separately and fits snug. It's proprietary to the cooler since it fits perfectly. Yes, it's also priced in the $40 range. I think $48, but around there.

When you will step to lithium-ion batteries, You will be impressed how the range can be on 36V 10Ah. Just because the efficiency (small voltage drop), less weight, and the chance to discharge the batteries with not harming them. Don't forget SLA batteries under 30% start to be in the dangerous SOC for the chemistry, that means less capacity the next time you will full charge.

5 - Preventing melting. This is obviously the biggest thing since I've already experienced this. I'm reading up on Cycle Analyst computer to help limit the amps drawn when going up slopes. Still reading. I know it's the best apparently. Pricy though at $170. Wondering what alternatives there are. Not looking to break the bank. Not looking to have a $1,000 ice chest. And since this is technically a scooter, there's no advantage of the pedal assist readout feature of the newest V3 model. Perhaps there's something more geared towards my needs at a much lower price.

your throttle is the best Amps limiter. Instead of limit your Amps through a CA, try to make the wiring capable for your requirements, your motor and controller are inside the safe power rate.

This is the specs for the 500w motor that I have: http://unitemotor.com/en/productmin.htm. Not sure how to make sense of all that.
"full load current" looks important.
Am I understanding correctly that the rating of 24v/36v/48v means that I could technically run 48v through this w/o frying the motor? If that's the case, then I have nothing to worry about as far as putting only 36v through it, correct?

You mentioned you wanted to see photos. They're mostly all on Instagram. I believe you can access it through the web too. IG @ricecooler. The initial ones are uploaded on e-bike blog in my signature.

Which one is your motor?
As you see those motor has a voltage range, when the voltage is rated just as one value, it just to show how is the rpm with no load at that voltage, and the standard voltage use. You can use more or less voltage depending on your use. If you gonna make hard climbing, more Volts could make burn your motor. If you are gonna make typical use, flatenning, inner city, 50% more voltage or even 100% can be safe if you put the right controller.

For overvolting, I had to connect the batteries in series to up the voltage while keeping the amperage the same. As I understand it, connecting it parallel would maintain the 12v capacity even for all three batteries but would triple the amperage 15x3 = 45ah.

UPDATE:
So it turns out the motor is not toast. It was only the controller (and associated melted connectors) that need replacing.
A company that upgrades these coolers has mentioned on his website that it's typical to experience melting connectors on the cruzin cooler product. As a solution, he recommends doing a butt connection for the wires connecting from the controller to the motor and also to the battery. That'll be a project for this week as I hadn't done that in my overvolting this past Saturday.

your parallel assumptions are right.

a typical experience.. they just use the wrong gauge size

I will be attending your updates

 

[mark5]

Use thicker wires and good connectors to replace your burnt wiring and connectors. If your burnt connectors look like the cheap bullet connectors pictured below replace them with better connectors.

 

[kmxtornado]

The connectors are the plastic type that come with most controllers. I was told that it's actually typical for the ones connecting to the motor and battery to each melt over time on these Cruzin Coolers. I was recommended to use the heat shrink butt connectors which I did last night. I wrapped it up in black tape too. You think this is good or should I have a different type of connector? I'm all ears b/c I really don't want anymore melting if there's something I can do about it as far as connectors go.

 

[amberwolf]

Do you have to disconnect things much? If not, just solder directly, especially for the motor/controller connection. You might be able to do it on the battery, too.

Basically you want the lowest possible resistance ont eh connection, with little or no chance of corrosion from humidity/etc.

 

[kmxtornado]

I would never have to disconnect it unless the motor blows out in which case, I'd have to swap it. Other than that, everything can be hardwired. I've only soldered once before in my life, but with the help of Youtube and YouGuys, I'm sure I can handle it. We'll see how the butt connectors work from out. if it happens again, I'll try my hand at the solder thing. Thanks for the recommendation.

 

[kmxtornado]

The overvolting is complete! The cooler now hauls @$$! Pretty amazing upgrade. The difference is almost unbelievable. Thanks to Tom from cruzincoolerupgrades who provided the kit which included:

1. 36v charger
2. Upgraded 36v throttle with battery reading and key. Now I don't have to worry as much about theft when I walk away from the cooler at shows and events. Plus the thing weighs a ton now so it's even hard for someone to snatch. Speaking of which, my alarm battery is out. Needs replacement.
3. 36v controller
4. All the connectors
5. Fairly detailed written instructions although the layout of it could've been better so it's more easy to read. Outline format would've been better than paragraph layout, but that's just me being picky.

Soon after the installation, I found the acceleration and torque had improved at ton and I quickly ordered a speed controller. Batteries I bought separately from coolermods.

24v controller was swapped with a 36v one and the cooler now uses three 12v 15ah batteries in series instead of just two 12v 18ah ones. For all the batteries to fit into the battery case though, I had to cut down the amp hours of each battery due to physical size limitations. I didn't have to drop down to 12ah since I found some 15ah batteries that are the same size as the 12ah ones.

Fits perfectly in the battery box.

Experienced some hiccups along the way, but all has been resolved with some troubleshooting and some advice from some members of the forum: http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=70815. Thanks again guys for all your input and recommendations! Turns out it was just the battery connection wires that came loose. Tabs from the new batteries are an odd 7.75mm wide instead of what appears to be a standard 6.3mm. I used the same quick connectors, but just pried them apart a bit to make them fit. Not a custom fit, but worked with what I had. Wasn't able to find any 7.75mm ones anywhere.