SnowDrifter Posted February 20, 2015 Report Share Posted February 20, 2015 Ok.... So.... I need to figure out 3 things. Once those are figured out it's li-ion battery bank time Thing 1: I need a material. Rigid, fire resistant, and non conductive. Thermally insulating would be a bonus too. Separating cells from eachother in the scenario should one of them fail, the whole pack won't go up in flames Thing 2: Temperature control. Keeping the bank cool is easy. However I need a method to keep it above freezing. I'm willing to induce a small drain in the pack to heat itself with a blanket or something, but trying to keep it temperature controlled without completely draining the battery will be difficult. This is the biggest one I'm hung up on. Thing 3: Cell balancing en masse. While they make balancers for RC battery packs. trying to balance 50+ smaller packs with a cumulative 200+ah needs something a bit more... Elegant ~~~~~~~~SAY NO TO PHOTOBUCKET~~~~~~~~ Snow's DD-1 tracks here: https://www.stevemeadedesigns.com/board/topic/167433-snows-dd-1-tracks/ My take on OFC vs CCA: https://www.stevemeadedesigns.com/board/topic/110381-things-that-piss-you-off-in-the-car-audio-world/?do=findComment&comment=2461444 Link to comment Share on other sites More sharing options...
OrionStang Posted February 20, 2015 Report Share Posted February 20, 2015 If you can figure out number 1, I think a material of that type would also take care of number 2. I can't help with number 3. SMD Super Seller My Feedback Thread Link to comment Share on other sites More sharing options...
rockFord_Expedition Posted February 20, 2015 Report Share Posted February 20, 2015 Thing 1: Would some sort of metal coated with a fire retardant like this work? Maybe double up some plates of metal and put some expanding foam or insulation between the two for temp control? Thing 2: WHat's your budget? Could you use something like they use to keep reptile cages warm? Or the lamps that home "flower" growers use? Maybe connect it all to a TM-1 and set the first set point really low and have it connected to the heating element. Thing 3: Not sure about that one without doing some research. Old School/New School RF Build March 2015 SOTM Winner How to crimp large wire Link to comment Share on other sites More sharing options...
aculous Posted February 20, 2015 Report Share Posted February 20, 2015 Have you thought about LiFePo4 instead? I know you said you wanted to go ion but it would negate some of the issues and still give you really good performance. the price is usually the issue. And LiFePo4 has pretty good support for controllers and the like. Link to comment Share on other sites More sharing options...
SnowDrifter Posted February 20, 2015 Author Report Share Posted February 20, 2015 Have you thought about LiFePo4 instead? I know you said you wanted to go ion but it would negate some of the issues and still give you really good performance. the price is usually the issue. And LiFePo4 has pretty good support for controllers and the like. I might flip around on the specific plans as I get details worked out. However regardless of the specific chemistry, they'll all need cell balancing, for safety each cell will be isolated from eachother(non-conductive material bit) and I don't know of any chemistry that can safely be discharged/charged below freezing ~~~~~~~~SAY NO TO PHOTOBUCKET~~~~~~~~ Snow's DD-1 tracks here: https://www.stevemeadedesigns.com/board/topic/167433-snows-dd-1-tracks/ My take on OFC vs CCA: https://www.stevemeadedesigns.com/board/topic/110381-things-that-piss-you-off-in-the-car-audio-world/?do=findComment&comment=2461444 Link to comment Share on other sites More sharing options...
aculous Posted February 20, 2015 Report Share Posted February 20, 2015 well ok some do some don't. You can get packs that already have the controller built in and are 12v, or you get a bunch of 3.2V cells and run a controller. Most controllers are for individual cells and then you have a "brain" that runs all of those cells. Pricing is high by the way. Like a big bank for a electric vehicle is about 15K$ so for audio you are probably talking anywhere from $1k-5K$ mind you the controller is usually more than the batteries. for heat you could use the DEI lavamat type stuff they use for turbos. Or certain types of kevlar. Apparently LiFePo4 is extremely stable and over voltage tolerances are 10-20% or something like that. Link to comment Share on other sites More sharing options...
SnowDrifter Posted February 20, 2015 Author Report Share Posted February 20, 2015 well ok some do some don't. You can get packs that already have the controller built in and are 12v, or you get a bunch of 3.2V cells and run a controller. Most controllers are for individual cells and then you have a "brain" that runs all of those cells. Pricing is high by the way. Like a big bank for a electric vehicle is about 15K$ so for audio you are probably talking anywhere from $1k-5K$ mind you the controller is usually more than the batteries. for heat you could use the DEI lavamat type stuff they use for turbos. Or certain types of kevlar. Apparently LiFePo4 is extremely stable and over voltage tolerances are 10-20% or something like that. Wasn't planning on a controller. The way it'll be set up there's no need. Only need something for cell balancing One thing I'm not sure about is insulating it. Would the insulation be enough to stop it from freezing? ~~~~~~~~SAY NO TO PHOTOBUCKET~~~~~~~~ Snow's DD-1 tracks here: https://www.stevemeadedesigns.com/board/topic/167433-snows-dd-1-tracks/ My take on OFC vs CCA: https://www.stevemeadedesigns.com/board/topic/110381-things-that-piss-you-off-in-the-car-audio-world/?do=findComment&comment=2461444 Link to comment Share on other sites More sharing options...
rockFord_Expedition Posted February 20, 2015 Report Share Posted February 20, 2015 well ok some do some don't. You can get packs that already have the controller built in and are 12v, or you get a bunch of 3.2V cells and run a controller. Most controllers are for individual cells and then you have a "brain" that runs all of those cells. Pricing is high by the way. Like a big bank for a electric vehicle is about 15K$ so for audio you are probably talking anywhere from $1k-5K$ mind you the controller is usually more than the batteries. for heat you could use the DEI lavamat type stuff they use for turbos. Or certain types of kevlar. Apparently LiFePo4 is extremely stable and over voltage tolerances are 10-20% or something like that. Wasn't planning on a controller. The way it'll be set up there's no need. Only need something for cell balancing One thing I'm not sure about is insulating it. Would the insulation be enough to stop it from freezing? Should be easy enough to test right? Now is the perfect time also. Build an insulated enclosure, like 1/12th scale or something and test it. Also, what if you got ahold of the auto defrost hardware off of an old fridge? Old School/New School RF Build March 2015 SOTM Winner How to crimp large wire Link to comment Share on other sites More sharing options...
rockFord_Expedition Posted February 20, 2015 Report Share Posted February 20, 2015 Find a thermometer with wired probe and peak hold feature. They have to exist. Old School/New School RF Build March 2015 SOTM Winner How to crimp large wire Link to comment Share on other sites More sharing options...
SnowDrifter Posted February 20, 2015 Author Report Share Posted February 20, 2015 Found this neat little thing. Would help with the temperature issue. Could set it to 3-4c in conjunction with a battery warmer and if would keep the pack from going below that temperature Now I just need to figure out the material to use for insulation/isolation and an effective means of balancing http://www.escol.com.my/Projects/Project-03(Thermostat-1)/Proj-03.html ~~~~~~~~SAY NO TO PHOTOBUCKET~~~~~~~~ Snow's DD-1 tracks here: https://www.stevemeadedesigns.com/board/topic/167433-snows-dd-1-tracks/ My take on OFC vs CCA: https://www.stevemeadedesigns.com/board/topic/110381-things-that-piss-you-off-in-the-car-audio-world/?do=findComment&comment=2461444 Link to comment Share on other sites More sharing options...
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