Modified traxxas ez peak dual charger (overheat solved)

[eMonlger2.0]

I know this is not a ideal solution because it's a generally poor charger compared to high end chargers that also charge with IR but I had this and it had overheating issues so until I can get a good charger I just fixed this one with parts I had on hand and about 2 hours of work.
You can squeeze a 40x40x20 fan if you slot the mounting holes.
Change out the heat sinks on the mosfets with quality thermal compound.
Move the existing 20x20x10 fan to add some air flow.
Drill various holes to help air move
And move the fan connections directly to the powersupply. The existing fan power is 7.3 volts. Moving the connections to the main powersupply gives better fan power 14something volts.

When I did this I found that all but one of the mosfets were not adequately soldered and that probably was the issue I had.

No issues anymore and its warm to the touch S before it was very hot but the air flow is about 3x as much now and the air is hot but that's good. Its moving the heat.
The existing fan ran on 7.25 volts so about 4 to 5 cfm
Now both fans move about 16 cfm maybe.

 

[bill_delong]

nicely done, this sort of ingenuity proves to me that you're going to be a great asset to the community!

 

[eMonlger2.0]

It does not show well but that solder joint on the mosfet was half cracked and all 3 of them have not enough solder to make a complete connection. The others were similar.

 

[eMonlger2.0]

SO just a bit of an update, I figured out that this issue I had been actually 2 issues hiding as one.

1st issue was that it was indeed either thinking it was overheating or it was overheating during some charging operations and that some of the mosfets were not soldered correctly. I think that it would have been fine if I used it casually.
the 2nd issue, the more main issue that I still have but I DID solve, is that the batteries I have the issue with are the 3s 5500 50C batteries. They are just too high of a discharge battery for the charger to put into storage mode. I have tested this a few times now and what happens is it charges it and overshoots the voltage, then discharges it accordingly just a bit. I confirmed this by measuring the voltage before the overheat trigger and after on both the 3s 4,000ah \30C batteries and these 50c ones. These chargers overshoot and discharge down by about .1 volts from the target 11.5 from 11.6 when it starts the discharge. I think this is due to the nature of the cells and that it charges it as a balanced charge so when say the 1st highest cell reaches its charge but by the time the 3rd lowest cell is fully charged into storage mode it has to discharge a tiny bit off the 1st and 2nd highest charged cells but it can ONLY do this via discharging all 3... IDK but that’s what I think is happening or something close to it. These chargers clearly can NOT handle these high discharge 50c batteries or maybe these batteries I have are just not up to snuff, yea I know I know, different charger IR... so on and so forth.
Hope this helps others.
The mods I did here DEFINATLY help it out a lot and I have NOT had any issues discharging or charging or storing the 30C batteries that I DID have issues with before. SO I just have to live with it until I can get a nice proper charger.
Thanks for the support!

BTW these are the 50C i have. I have converted everything i run into EC5

 

[bill_delong]

Consider running the car to LVC first, then put it in storage mode so it's "charging" instead of "discharging" to get to storage setting. My charger takes less than 30 sec to hit storage voltage using this method

 

[eMonlger2.0]

Consider running the car to LVC first, then put it in storage mode so it's "charging" instead of "discharging" to get to storage setting. My charger takes less than 30 sec to hit storage voltage using this method

I'm not sure i understand why you said that. When i am done bashing and the revo is no longer able to move because the batteries are done, they are at like 9.5ish volts, when i am done bashing for the day i put them away by putting them into STORAGE mode (11.5v) HOW would i benefit from A: adding cost and headache by adding a battery monitor and having to check each cells charge while i bash, and B: only use HALF of the batteries charge only to "save" time when i go to store them?

Maybe i am missing something here but i was under the impression that i am CHARGING the batteries when i put them into storage mode! or did you not read my post above how its at the very end of the storage charge, discharging a tiny bit and that the big 50C bats i have are the issue?

Please explain it to me, I'm new to lipo RC, but i clearly know my way around electrics
I'm not being condescending, i genuinely am new to this and i do NOT know much about this stuff, just enough to ask questions!

 

[bill_delong]

Generally when most people put their packs in storage mode they are "discharging" from a higher voltage which puts more strain on lower quality chargers than charging because the internal heat sink absorbs the energy which can cause it to overheat.

LVC or "Low Voltage Cutoff" is a feature included in Traxxas ESC's to automatically shut off the ESC when the pack voltage reaches a pre-set limit, typically anywhere from 3.2 - 3.6 V/cell under load. The voltage will then bump back up at rest where the cells can very quickly hit the desired target of 3.8V/cell with minimal load on the charger.

I've grown complacent knowing that cells are close enough to storage that I never actually put them in storage mode with my charger anymore, I simply run them to LVC knowing that is the desired storage voltage for me, easy peasy

 

[eMonlger2.0]

Generally when most people put their packs in storage mode they are "discharging" from a higher voltage which puts more strain on lower quality chargers than charging because the internal heat sink absorbs the energy which can cause it to overheat.

LVC or "Low Voltage Cutoff" is a feature included in Traxxas ESC's to automatically shut off the ESC when the pack voltage reaches a pre-set limit, typically anywhere from 3.2 - 3.6 V/cell under load. The voltage will then bump back up at rest where the cells can very quickly hit the desired target of 3.8V/cell with minimal load on the charger.

I've grown complacent knowing that cells are close enough to storage that I never actually put them in storage mode with my charger anymore, I simply run them to LVC knowing that is the desired storage voltage for me, easy peasy

well i dont have the traxxas ESC, I'm running a Spektrum Firma 150a, ill have to dive into that and actually check the voltage after running and after cooling the batteries down. Thanks though, now i understand what you are taking about.
i have put them into storage mode right away and then sometimes hours after useing them, they seem to take the same time to charge to the stored state!

 

[Jerold]

SO just a bit of an update, I figured out that this issue I had been actually 2 issues hiding as one.

1st issue was that it was indeed either thinking it was overheating or it was overheating during some charging operations and that some of the mosfets were not soldered correctly. I think that it would have been fine if I used it casually.
the 2nd issue, the more main issue that I still have but I DID solve, is that the batteries I have the issue with are the 3s 5500 50C batteries. They are just too high of a discharge battery for the charger to put into storage mode. I have tested this a few times now and what happens is it charges it and overshoots the voltage, then discharges it accordingly just a bit. I confirmed this by measuring the voltage before the overheat trigger and after on both the 3s 4,000ah \30C batteries and these 50c ones. These chargers overshoot and discharge down by about .1 volts from the target 11.5 from 11.6 when it starts the discharge. I think this is due to the nature of the cells and that it charges it as a balanced charge so when say the 1st highest cell reaches its charge but by the time the 3rd lowest cell is fully charged into storage mode it has to discharge a tiny bit off the 1st and 2nd highest charged cells but it can ONLY do this via discharging all 3... IDK but that’s what I think is happening or something close to it. These chargers clearly can NOT handle these high discharge 50c batteries or maybe these batteries I have are just not up to snuff, yea I know I know, different charger IR... so on and so forth.
Hope this helps others.
The mods I did here DEFINATLY help it out a lot and I have NOT had any issues discharging or charging or storing the 30C batteries that I DID have issues with before. SO I just have to live with it until I can get a nice proper charger.
Thanks for the support!

BTW these are the 50C i have. I have converted everything i run into EC5
View attachment 168755

I had a similar issue where I was over exceeding the discharge wattage and I killed the charger. This was an ISDT, and would expect better, like it would limit the wattage. But designed in China is still designed in China regardless of how much you pay for it. It's amazing how simple it is to put in over current protection, but they don't do it to say $0.30.

If you have a few $$, a solid charger and discharge is a good investment. They all eventually turn to bricks, but the higher wattage ones seem to last longer. I always double check my charging wattage and keep it to about 60% of the max. External power supplies help as well, by keeping the heat out of the charger. And I use a separate unit for discharging, which is super easy. At 250W of discharge power, it drops them down in no time at all. Then top them off with the charger to storage voltage.

My setup can do 700W, but I keep it well under that. It's also better for the batteries. The wattage adds up quickly.

9.5A @ 16.8V (4S) on two channels is > 300W. This is one C for my larger batteries.​

 

[eMonlger2.0]

i wont really ever use a discharger. I'm not interested in a dozzen RC's or drones or whatever, i just enjoy bashing and fixing the revo and thats how i was back in my nitro days. I have WAY too many hobbies to invest my $ and time into enough to consider a setup like that. if i get rained out i just bash in the rain. I was litterally just tossing up hail pellets on the ground durring a hail storm. SO ill just charge it to a storage state. What you just said about the chargers all being junk, i completly agree, there is no reason to really chose one over another in the end at a certain point. the one i have will probably do for a while or long enough that i may slow down playing with it.

 

[F.R.S. Ninja_007]

I can’t believe you’d open up an Ez-Peak Dual; I’d just contact Traxxas customer support.

 

[Jerold]

i wont really ever use a discharger. I'm not interested in a dozzen RC's or drones or whatever, i just enjoy bashing and fixing the revo and thats how i was back in my nitro days. I have WAY too many hobbies to invest my $ and time into enough to consider a setup like that. if i get rained out i just bash in the rain. I was litterally just tossing up hail pellets on the ground durring a hail storm. SO ill just charge it to a storage state. What you just said about the chargers all being junk, i completly agree, there is no reason to really chose one over another in the end at a certain point. the one i have will probably do for a while or long enough that i may slow down playing with it.

I get what you mean. When I run the Slash or TRX4 I just run them til they don't go. The speed run cars pull a lot of current (Voltage droop), and generate a lot of heat, the # of daily runs are limited and I usually don't get below storage charge at the end. That's where the discharger is good.

In the past I was a bit caviler about battery health, then I killed two batteries in one week. I figured a bit of due diligence could save me some money. That week they were both killed by heat. My charging is always done outside and I did it in the direct sunlight. Then left a battery in the back of the 4runner (aka green house). No I'm more careful about charging and make sure I account for all my batteries when I come and go.

Anyways glad your charger is up and running.

 

[RustyUs]

SO just a bit of an update, I figured out that this issue I had been actually 2 issues hiding as one.

1st issue was that it was indeed either thinking it was overheating or it was overheating during some charging operations and that some of the mosfets were not soldered correctly. I think that it would have been fine if I used it casually.
the 2nd issue, the more main issue that I still have but I DID solve, is that the batteries I have the issue with are the 3s 5500 50C batteries. They are just too high of a discharge battery for the charger to put into storage mode. I have tested this a few times now and what happens is it charges it and overshoots the voltage, then discharges it accordingly just a bit. I confirmed this by measuring the voltage before the overheat trigger and after on both the 3s 4,000ah \30C batteries and these 50c ones. These chargers overshoot and discharge down by about .1 volts from the target 11.5 from 11.6 when it starts the discharge. I think this is due to the nature of the cells and that it charges it as a balanced charge so when say the 1st highest cell reaches its charge but by the time the 3rd lowest cell is fully charged into storage mode it has to discharge a tiny bit off the 1st and 2nd highest charged cells but it can ONLY do this via discharging all 3... IDK but that’s what I think is happening or something close to it. These chargers clearly can NOT handle these high discharge 50c batteries or maybe these batteries I have are just not up to snuff, yea I know I know, different charger IR... so on and so forth.
Hope this helps others.
The mods I did here DEFINATLY help it out a lot and I have NOT had any issues discharging or charging or storing the 30C batteries that I DID have issues with before. SO I just have to live with it until I can get a nice proper charger.
Thanks for the support!

BTW these are the 50C i have. I have converted everything i run into EC5
View attachment 168755

I would think during the constant voltage (CV) part of a balance/storage charge (if bringing cells up in voltage) will not generate excessive amounts of heat as my charger's fans RPMs drop off drastically as amperage drops. I'd give you a link to TJinTech, but that site doesn't exists anymore. That had a great explanation of constant current/constant voltage (CC/CV) part of a balance charge process.