As many are aware, the Typhoon H battery supply appears to be drying up. Either there are few to be found or their apparent age (bases on case labels) is long in the tooth. I have embarked on a battery research project to develop the means to adapt after market batteries for use in the Typhoon H. Once the research is completed I'll start another thread to show how to do it but until then there are some considerations that are sort of important that I'd like to see H owners kick around a bit. This thread is for discussing those considerations. Ya'll should view each paragraph as a series of questions but formatted more like data points. I'd
really like to know what ya'll think. I may not make use of any of it but, I'm certain to be influenced by some of it. It's a little more complicated that it might first appear and I know darn well that whatever I put out there is going to be criticized to death. That's OK as the general principle is adaptive.
The Typhoon H has a few design factors that have to be considered, along with cosmetics that will be more important for some people than others. The Typhoon H hard case battery is designed to fit a specific dimension within the aircraft, with the battery bay a plastic fixed box structure under the airframe. So whatever battery is used it has to fit the width and height of the battery box. However, we have a battery bay length of 132-133mm that can either be adhered to or exceeded. This is where primary considerations come into play as batteries vary considerably in length and weight. Do we consider longer batteries that will protrude aft of the H body or might only batteries that fit completely within the bay be the only consideration? If electing to use only batteries that will be concealed within the aircraft are selected the number of batteries that could be used decreases significantly.
Battery weights obviously vary considerably, with battery weight variably induced by C rating, mA ratings, manufacturing processes, and quality levels. Using 6 factory batteries as weight samples, the Typhoon H battery has an average weight of 571.26 grams. The weight spread between the 6 sample batteries ranged from 565.1g to 575.7g. The case by itself weighs 42 grams, +/- 5 grams. Just for general info purposes, the UltraX batteries average 565 grams using only two to obtain that average. That takes us to alternative battery weights. After a full day of research I've come up with 11 different batteries that "could" be used in the existing Typhoon H battery bay, but lengths, C ratings, weights, and mA capacities vary considerably. Surprisingly, a dimensionally smaller battery will not necessarily lighter than a dimensionally larger battery. The same applies to lower versus higher mA capacities.
The most common battery capacity available runs between 5000 and 5200mA. Although Yuneec labels their factory battery as 5200mA I don't believe that for a second. Without going into detail there are several factors that strongly suggest it is a 6300mA battery so selecting a 5000mA to 5200mA battery would, IMHO, leave everyone with a lot less flight time than they currently experience. As there is considerable expense with buying and trying a bunch of different capacities my mission statement for this endeavor will only make use of
just one battery brand, in one size, and one capacity. I just don't foresee people contributing funds to expand the battery sample base. As things stand, the highest capacity battery I've found that will reasonably fit the battery bay is a 6800mA RC car battery that weighs 594 grams (a gain of 18.3g over the heaviest sample stock battery) with a length of 138mm, or 6mm (0.23") greater in length than a stock Typhoon H battery. Other options weigh up to 619 grams with lengths as great as 168mm, which would leave 1.42" of battery extending to the rear of the aircraft body. There are of course larger batteries but the weights rise accordingly and generate questions related to effects on CG, aircraft stability, and increased power demands that would significantly offset increases in capacity.
Now we come to battery structure. Those that are only accustomed to proprietary batteries are used to having a hard shell case. Although that does make battery handling and protection simpler it is not the lipo battery industry standard. Soft wrappers are more the norm. A hard case adds battery weight and increases battery dimensions. Do operators have the ability to adapt to a battery structure different from what they are accustomed to? Can they alter their battery handling practices to allow safe handling of their batteries? Will they tolerate a battery security method that will require a little more personal effort and be a lot more visible on the exterior of the aircraft? Just how important are cosmetics?
Finally we come to price. How much will people be willing to pay for an alternative battery? Using 11 battery candidates the price range for an alternative battery runs from $32.81 to $149.00. There is one that costs over $200.00 but I don't see anyone going there unless they are procuring for a government agency. The $32.81 candidate is a 20C, 5000mA battery and in all probability not a good choice. The cheapest, but not a good idea. The $149.00 candidate is an 80C (waaaay more than we need) 6800mA, hard cased RC car battery. Unfortunately, the battery manufactures appear to be gravitating towards high C ratings. We don't need much if anything over 15C-20C but most of the batteries out there are in the 40C-80C range, costing us more in money and useless weight.
Something else to consider is that battery manufacturers are constantly introducing new batteries of various capacities and dimensions all the time. They are also constantly phasing out batteries of various capacities and dimensions, so whatever battery I land on may not be available next week, next month, or next year. Because of that the method of adaptation has to maintain the flexibility necessary to cross over to other batteries as they come and go.
So, your thoughts and comments
