Battery Cycling on a budget (Part I): DIY Battery Cycler
One question we always get is How do you get data? Battery cyclers are so expensive! Why yes! Yes they are! While gathering lots of battery data is extremely important to ReJoule's success, so is keeping the lights on. As an early stage cleantech startup, we're always grappling with the question of build (DIY) or buy.
There's no question that buying a cycler is the best approach...<em>if</em> you have resources and money. Companies like Digatron and Maccor have spent years developing and selling robust and durable battery test products with high precision. At ReJoule, we cannot wait for the day that we can buy an off-the-shelf, high precision, battery cycler (#startupgoals). Until then, we're opting for the DIY approach because we cannot afford such a high upfront capital cost. (Side note: if anyone from Digatron & Maccor is reading - we do happily take in-kind donations).
First let's consider the pros & cons of building your own cycler:
Pros:
Extremely flexible systems and data structures fit to your needs.
Lower capital cost.
If designed well, can be easily scale-able in adding more circuits.
Can be faster than buying off-the-shelf*.
If you're an engineer, it's a fun challenge to tackle. Might be a bad idea if you're not an engineer...
*Lead times for off-the-shelf cyclers can be upwards of 3 months
Cons:
Opportunity cost: requires engineering hours/resources that could be spent on other things.
Usually not as "pretty" as an off-the-shelf, packaged solution.
If poorly designed, can give inaccurate measurements.
If poorly designed, can be a nightmare to manage and scale
You'll notice a few keywords above are "if designed well". A less than desirable outcome is to spend months developing a cycler, just to realize that you're missing the accuracy/precision you need because of unforeseen integration problems. In the next post, we'll give some tips on building a well-designed DIY cycler.
Cheers,
The ReJouligans.