Batteries

All batteries are not created equal.

How they are treated affects their life. Temp - charging - depth of discharge - C/10

Too cold and discharged and a battery can freeze! Most charge controllers these days have the ability to use a temperature sensor to automatically adjust their charging rates based on battery temperature.

Typical battery technologies used today for backup power are varieties of lead acid. Lead acid batteries are further divided into flooded and sealed technologies. Each has its strengths & weaknesses.

Flooded batteries are typical for Starting Lighting & Ignition (SLI) applications like automobiles & trucks. Also so called deep cycle marine batteries are more like SLI than truly deep cycle. All have in common a Cold Cranking Amps (CCA) rating. These are designed for high current production for a short period of time, and physically they have small thin plates to achieve this. I do not recommend this type of battery for backup use.

There are also true deep cycle batteries that are flooded cells. These have been around for years in golf carts (T-105 type) and forklifts, floor polishers (L-16 type). They are very economical when used for backup, however need to be located outside or indoors in a sealed and forcibly vented enclosure due to their outgassing of explosive hydrogen during charging. They are economical and fairly long lived with proper use (charging/discharging) and maintenance (watering/specific gravity checking), but can be dangerous due to the presence of acid.

Sealed Lead Acid (SLA) batteries on the other hand require much less maintenance and typically can be used indoors. SLA batteries are further subdivided into Absorbed Glass Mat (AGM) and gelled electrolyte (Gel).

For most larger battery backup systems, I recommend the AGM technology.

All SLA batteries have stricter charging requirements than flooded cells. They typically require a 3 stage charger to prevent damage due to overcharging and possibly venting.

Other technologies of batteries are available and can provide higher density of storage, but have higher costs, very strict charging requirements, and limited configurations. Nickle Metal Hydride (NiMh), Lithium Ion are examples.

Wouldn't it be neat to have an adapter to be able to use your power tool's batteries for other purposes? I wish I had time to investigate this further, because I have a half a dozen of these batteries in use... Imagine a receptical on the back of your mobile rig that could accept one or more of these...

Power Distribution

Once you have a power storage plan, how do you get power to your gear?

We all know that the Anderson powerpole has become the standard for ARES/RACES interchangeability. This is a great advancement for us, as now we can be reasonably assured that our power sources and equipment can be used anywhere hams congregate.

I prefer to use the Rig Runner line of distribution products from West Mountain. I have a half a dozen in different sizes around the shack and in my go bags.

A word of advise here - the cable providing power to the RigRunner should be fused at the power source as well for the safest use.

PhotoVoltaics (Solar Panels)

Electricity from the sun. No moving parts.

PV cells are a neat thing. Combined into modules, modules combined into arrays, they are capable of providing maintenance free energy for periods over 30 years. Matching their characteristics to an application is the only trick here. Originally modules were manufactured to provide charging for 12 VDC battery systems.

Not many systems are designed to work on 12 VDC anymore. In a backup system (for your home or small industrial instrumentation) typical voltages are 24 & 48 VDC. This allows much smaller conductors to be utilized for connections & saves cost in cabling and over current protection. Most modules being manufactured today are designed for the residential & commercial grid-tied market. These applications utilize string of higher voltage modules connected in series to raise the voltage to the 300-500VDC level at 3-9 Amps per string. Strings are then paralleled to increase current. This also allows for much reduced conductor sizing, reducing voltage drop and copper costs.

Charge Controllers

Controlling the charging of your batteries is a key element in treating your batteries well, and increasing the longevity of them.

Charge too fast - too slow - voltage too high

Metering

How much power is laft in your battery? How much power does your station use? Important questions if you don't want to be caught incommunicado.