We have reached the end of a three-part series of articles on the power required to get an astronomer through a night of observing. We began by discussing battery types, distinguishing between a battery as but one component of a complete astronomy power solution, and then we identified the other components of this complete solution, which includes a case, outlets and their circuit protection, and a battery charger that will ensure that the battery is ready whenever it might be needed next.

At a high level, we found that battery usage can be defined in terms of a three-way trade space of battery capacity in amp hours, total amp load of the devices drawing power from the battery, and time that the device load can be sustained before the battery capacity is depleted. How the capacity and load relate to time is important because this is the basis for how the adequacy of a battery for a night of astronomy is assessed.

Next, we gave a similar treatment to replenishing the battery’s charge after a night’s use. We found a similar three-way trade space between capacity in amp hours, amperage supplied by the charger, and time. We distinguished between a straight battery charger and a smart charger and identified the advantages of a smart charger when it comes to preserving a battery’s useful life. And finally, we discussed the context for determining the adequacy of a charger, especially when there is limited time to recharge a battery for use on two consecutive nights.

And finally, we discussed some particulars regarding commercially available power solutions, and DIY power solutions. The DIY solutions require much more forethought to ensure that the end product produces the desired result, and we pointed out that some electrical skills and a sense of adventure on the part of the astronomer are required for going this route. But a big advantage that DIY solutions have over commercially available solutions, especially those involving higher battery capacities, is that the DIY solutions can be far less expensive for those who can do it.

We hoped that you have found this series informative, and useful as guide to the research that you may want to do in determining the amount of battery capacity is needed in your power solution, and in determining the correct charging capacity for your needs. And lastly, we hope that you have an appreciation for how commercially available units are alike, how they differ from DIY solutions, and for which might be the better route for you.

We would love to hear about your power solution, how you use it, and how it was decided. Helpful comments below are always appreciated.

© 2021 Jim Johnson and Doug Biernacki