not a car progress thread, but my latest mod. might be interesting for the lightweight fetish people on here
everything started about a year ago when I was looking for lightweight batteries for my twingo RS. all I found was the typical hawker 7kg bike battery, the varleys and all their lookalikes. but 7 kg battery would only safe 7kg of weight compared to the 14kg twingo stock battery... so I dismissed the idea
few weeks later at a local RC drift meeting one of the guys tried his brand new LiFePO4 battery pack... I asked him about it and he told me it's a nice technology... not as much punch as LiPo batteries but you can charge it with high current like a car battery so it is full in minutes... wait... did he say "like a car battery"?
later at home I did some research and found out that LiFePO4 is indeed a worthy alternative for crappy lead-acid cells. so I dug out a few manufacturers, found a cell that was easy to handle, offered huge capacity and even was nice to look at:
enter: the headway 40160 LiFePO4 cell
the beauty of those cells is that they are huge, compared to other cells. so you only need a few of them limiting the assembling time and point-of-failure rate. quickly I ordered a bunch and upon arrival I started to assemble a 12v 16Ah battery pack
the sheet underneath outlines the stock twingo battery dimensions. just to see how small the pack actually is, there's a standard issue redbull can right next to it
I charged it using my RC car charger and found out they came pretty well precharged. then all I needed to do was hooking it up to the twingo to test it... but that weekend I was attending a slalom race and in the class I was entering I was not allowed to modify the car and the tiny blue battery would have caused disqualification. so I put it aside for "later"
much later, as turned out. few months after building the cell I traded the twingo in for the clio which I am now driving for over 3 months... but today, I stumbled over the cell and couldn't resist to finally test it:
[youtube]FnaC7peUCrc[/youtube]
voila... it works. now it's time to do an endurance winter test
everything started about a year ago when I was looking for lightweight batteries for my twingo RS. all I found was the typical hawker 7kg bike battery, the varleys and all their lookalikes. but 7 kg battery would only safe 7kg of weight compared to the 14kg twingo stock battery... so I dismissed the idea
few weeks later at a local RC drift meeting one of the guys tried his brand new LiFePO4 battery pack... I asked him about it and he told me it's a nice technology... not as much punch as LiPo batteries but you can charge it with high current like a car battery so it is full in minutes... wait... did he say "like a car battery"?
later at home I did some research and found out that LiFePO4 is indeed a worthy alternative for crappy lead-acid cells. so I dug out a few manufacturers, found a cell that was easy to handle, offered huge capacity and even was nice to look at:
enter: the headway 40160 LiFePO4 cell
the beauty of those cells is that they are huge, compared to other cells. so you only need a few of them limiting the assembling time and point-of-failure rate. quickly I ordered a bunch and upon arrival I started to assemble a 12v 16Ah battery pack
the sheet underneath outlines the stock twingo battery dimensions. just to see how small the pack actually is, there's a standard issue redbull can right next to it
I charged it using my RC car charger and found out they came pretty well precharged. then all I needed to do was hooking it up to the twingo to test it... but that weekend I was attending a slalom race and in the class I was entering I was not allowed to modify the car and the tiny blue battery would have caused disqualification. so I put it aside for "later"
much later, as turned out. few months after building the cell I traded the twingo in for the clio which I am now driving for over 3 months... but today, I stumbled over the cell and couldn't resist to finally test it:
[youtube]FnaC7peUCrc[/youtube]
voila... it works. now it's time to do an endurance winter test