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It was easy to choose batteries for our Victoria’s. The preference was five AA batteries (approx. 6 Volts in a rechargeable battery or 7.5 V. in a standard battery), though a significant number of our skippers elected to use four cells (approx. 4.8 V. in a rechargeable battery or 6 V. in a standard battery). The argument for five cells is faster servo movement and increased servo torque, both a boat performance benefit.
Whether you are using four or five cells there is another parameter to be kept in mind. That is the ampere hour rating. An ampere hour (abbreviated Ah, or sometimes amp hour) is the amount of energy charge in a battery that will allow one ampere of current to flow for one hour. So, a milliampere hour (mAh) is 1000th of an ampere hour. As a practical matter the mAh value determines how long a device will run before the battery needs recharging. In the Victoria, I typically used 1500 – 2000 mAh batteries. This guaranteed that I could sail the boat all day on one charge.
A quick divergence. Standard, non-rechargeable, batteries are 1.5 Volts each. Some of our skippers used 4 standard batteries in a container with complete satisfaction. As far as I know, one cannot purchase five cell containers.
Micro Magic Batteries
The Micro Magic ready-to-sail weighs less than one-half the Victoria (860 gm or about 31 oz., less than 2 lb.). The most c
ommon battery selection is five rechargeable AAA’s of about 700 mAh. According to Mike Eades, this will provide several hours of racing time. His view is to use this low mAh battery and change it out during the lunch down time at a regatta. My 800 mAh pak weighs 66 gm., about 2.4 oz. After the pak was assembled and shrink wrapped by Batteries Plus, I sealed all openings with silicon seal to keep the water out.
The following is the configuration and weights of my battery paks for reference. Obviously, the most significant weight variable is the number of cells. But, also n
otice that the weight is also associated with the mAh rating.
5 Cell, 800 mAh AAA = 66 gm (2.37oz) (this is the 5 800 mAh battery pak shown above)
4 Duracel, 1150 mAh AAA in a plastic battery container = 54 gm (1.93 oz)
5 cell, mAh unknown AA = 133 gm. (4.75oz) (my guess on the apparently low weight is lesser mah rating)
4 cell, 2000 mAh AA = 120 gm (4.34oz) (I have two paks at this weight; both Batteries +; so no surprise)
Note that the 5 cell AA weighs 133 gm while the 5 cell 800 mAh AAA weighs 66 gm, a 2.4 oz difference.
Batteries for Battery Paks
My new battery pak for my Micro Magic is composed of five tabbed batteries I found on the Internet. Tabbed batteries make it easier to assemble paks. I started my search for cells wanting Panasonic Eneloop’s. I could not find them. Next I investigated tabbed batteries from any source. The image to the right shows the typical battery appearance that I found. Though t
he mAh rating was given, there was no information upon which to make a quality judgement. Somehow, I
made the decision to purchase them from QRW Solutions on Amazon (Duh! Where else?). Like I said previously, quality unknown. I purchased six cells; the company sent me seven (i hope that isn’t an expression of their expected quality). My total cost was $10.
I have constructed a battery pak using short pieces of wire
as “tabs”. One soldiers the wires to the batteries, preferably using a soldiering gun as it can product high heat very quickly. High heat applied for a second to properly prepared batteries does the job without damaging the cells. Using wire connections is not desireable. It took too long to deal with each soldier joint as the wire wanted to fall off of the battery. There are three choices to this subject if you want to prepare a pak. Buy tabbed batteries, buy the flat pieces of metal shown in the red-background image, or buy tabs with holes as shown in the other image.
Based upon my experience, the first choice is the easy way to go, whether you assemble the pak yourself or have Batteries Plus do it. The second choice is the tabs with the holes. Based upon videos I have watched on the do it yourself approach, they look like the easiest to me.
I asked the folks at Batteries Plus about their opinion about the best AA, AAA batteries. It was Sanyo and Samsung at the top. This needs to be investigated, because when I did a “best aaa battery” i did not see these companies.
Note: all weights were taken on my kitchen scale. I know it is not exactly correct, but for our purposes here it is sufficient.