Cooling station for NIMH batteries and Imax B6 charger

[Halon]

Do you still use nimh batteries? Have they ever become so hot that they are untouchable while being charged? Does your IMAX B6 get really hot while charging you battery? Yes? Then let me show you what I had to do in order to reduce the heat on my nimh packs while rapid charging them with my IMAX B6 lipo charger.

First of all, this is the final product:


Materials I used:
K'nex
Lab PSU (Power Supply Unit, you know those that come in the computers)
Computer Fans (12v)

Ok, I won't explain each specific step on how to build the psu or the station but I'll tell you the general concept behind it.
WARNING: Converting a PSU into a Lab PSU can be dangerous (and lethal), if you decide to try this out is on your own risk. The little psu on the picture throw 12 AMPs DC and that can kill someone, be careful! Ok, there, I said it!

Here is how it works:

You'll notice that there are 2 fans, one big (top) and one small (bottom). The one at the top pushes air toward the battery and the one at the bottom pull air from the battery. This way the battery does not get way too hot while charging (yes people it'll still get warm) improving the charging and extending the life of it.

The battery does not touch the ground, this way air flow is constant on the top and bottom of the battery.


Also the fans will keep the charger cool, yes I said cool, the heat from the charger will be almost none (at least from what I have experienced):


Here is a video I made about the sation:
NuKE RC - Cooling Station for NIMH packs and IMAX B6 LiPo charger - YouTube
Please read description if you watch the video, there you'll find how to make your own Lab PSU!

Here are more pictures of the station if interested:
Charging Station Photos by utuadorccrawlerteam | Photobucket

Notes:
1) This setup does not work with hard case lipos (and I haven't try soft case since I don't have one....yet).
2) If you haven't figured out, you still can use the fans to keep the charger cool while charging LiPos outside the station (though my lipo never gets warm).

I hope you find the info useful.

Thanks for reading.

[RCSparks]

OH WOW MAN! So Cool!

Thanks so much for posting this. Im gunna put it in the Articles Section! PROMOTEDDDDDD! :~) Very creative and super awesome! Great Job!

[Holcomb2010]

Wow! Never have thought to do something like that for my batteries lol they do tend to get warm sometimes going to have to out this idea to use!

[Juddp]

I love the use of k'nex! I still have mine from when I was little. Great idea!!

[Halon]

OH WOW MAN! So Cool!

Thanks so much for posting this. Im gunna put it in the Articles Section! PROMOTEDDDDDD! :~) Very creative and super awesome! Great Job!

Wow! Never have thought to do something like that for my batteries lol they do tend to get warm sometimes going to have to out this idea to use!

I love the use of k'nex! I still have mine from when I was little. Great idea!!

Thanks to all.

[KJRC28]

this thing is sweet, ill definantly be building one!

[Magnat007]

Um.. Heat is needed to keep the chemicals inside a NIMH active...
When you say they get warm.. are they reaching warm to touch ?

Batteries should be allowed to Cool at room tempreture before charging... Force cooling them can lead to a shortened life span..

This Idea can be further expanded by using a Fridge rack or Baking tray and Cooling down motors after a run...



I positioned the fan to blast air straight over the HPI Sprint 2's motor.. Used to use it when racing, In between runs I would cool the motor...
It expanded the lifespan on my Silvercan motors..

[Halon]

Maybe I should tell the story of why I built the cooling station...

Location: Puerto Rico, Season: Summer, Outside temp: Aprox. 95 F, Battery: Tenergy 7.2v 5000nah.... I normally give quick charges to batteries( I want the fun now!), so that day I did the same. Everything was rightly connected, I turned on the power supply, the imax b6 turned on, I set charging parameters and then hit start. Aprox. 40 min later, imax do the beeep sound to let me know charging was complete (charging time was right for me), so I went powered down the PSU.....but when I touched the battery it was impossible to handle way too hot, and I mean WAY TOO HOT. It seems that the combination of the heat from the room and the quick charge was too much for the battery. Fortunately the battery survived. On the next day I, again, quick charged my traxxas 8.4v 3000mah and guess what, also too hot again (but less than the first one). So, I decided that I had to do something about this, so I started to look around for thing that could help me. I found the pc fans and then it came to my mind the k'nex and so I built the cooling station.

How much it helps to keep the temp down of the battery? Well, it depends on the room temperature, but the station has helped to keep the temperature of the battery and charger lower that they could actually reach.

When you say they get warm.. are they reaching warm to touch ?

Yes Magnat007, its warm to the touch, but again I'm talking about quick charging the battery. I wish I could give you actual numbers but I don't have a infrared thermometer, all I have is la lab thermometer (that I have tried to set to capture the temp). All I can tell you is that the station helps to lower the temperature of the battery while charging. Again, how much low the temperature will drop depends on the room temperature.

Batteries should be allowed to Cool at room tempreture before charging... Force cooling them can lead to a shortened life span..

I've never cool down the battery with the station after using it on my rc. So they normally cool down at room temp for that case.

I'll try to get actual numbers to show the difference in temp, but no promises. I hope this will give you a more in depth about the station. There are many variable that can affect the outcome.

[Halon]

So, as you could see in the first post, the connectors are somehow exposed and accidents could happen. So I decided to change the connectors to bullet terminals.

Here is the final product:


Basically I soldered 6 cables to the 2 banana connectors (3 cables per banana connector), negative (black) on one connector and positive (colorful ones) to the other. Paired the both of them using heat shrink tube to have better organization:
]

I striped the bullet terminals from the plastic covering them, crimped them and then added some soldering to add strength:



Here is in action:


Here you can see a video of the whole thing working: Update to the cooling station - new connectors. - YouTube

Notes:
1) The bullet connectors are easy to connect but a pain to disconnect, use a Phillips screwdriver (+) to expand the female side.
2) Wondering why there's heat shrink in some cables and others not.....well i forgot to put it before soldering.

Thanks for reading.

[Halon]

Thanks everybody for your "Likes", they are most appreciated.