LiFE Battery Packs

Webmaster note: I hate the old clunker lead-acid batteries that UV light manufacturers sell. They are old technology, heavy, and inefficient. In spite of my best efforts UVSystems refuses to offer an alternative to an otherwise excellent lamp package, WTC dealers (some - www.polmanminerals.com) are working with the company to offer an alternative. I developed this write-up with the thought of offering these packs as a service to the hobby but quickly realized that it’s really much simpler to sell rocks (no support). These packs are available off-the-shelf from many RC dealers; the enterprising hobbyist can certainly adapt them to use with their UV light.

ONE CAVEAT: LiFE batteries are very sensitive to over-discharge. If you use one of these packs you must not drain it. I have LED indicators on my lamp which tell me when the battery dips below 12v, and I simply switch packs. Someday I will design a voltage cutoff circuit to automatically disconnect the battery when it falls below a certain voltage.

(Also, building an NiMH battery pack - I wrote an article on building your own NiMH battery pack several years ago for the UVwaves (FMS publication). I have included it here. It’s still a much better way to go than lead-acid.)

The ultimate lithium ion battery technology for UV Field Lights

With an exceptional “power to weight” ratio, durability, and safe operation, UV-PowerPaks are the next generation battery for handheld portable UV lamps. Using patented lithium-ion chemistry (based on new nanoscale material developed at MIT), UV-PowerPaks provide high performance and abuse-tolerance unmatched by any other battery technology.

Power

• 13.2vdc – extra power, increased light, less weight. Lightweight, small battery packs - 2.3AH or 4.6AH.
• Maximum power to end of charge, no degradation in lamp output.
• Ultra fast charge –less than 5 minutes to charge to 90% capacity, full charge in less than one hour. No more waiting overnight for a charge.
• Thousands of recharge cycles when used at low-discharge rates, unmatched by any other battery technology.
• More volts, longer, than other batteries - UV lamps powered by 12vdc batteries are capable of operating at 14vdc (the output of a charging car battery) and shine brightest at the higher voltage. A constant 13.2v instead of a slowly dropping 12v provides more light output, and brighter finds! Lightweight means you can carry more rocks!

Safety

• Inherently safer chemistry
• Superior abuse tolerance
• Safer technology than NiMH, NiCD or even SLA - Nanophosphate™ technology is designed to be highly abuse-tolerant while meeting the most demanding requirements of power, energy, operating temperature range, cycle life and shelf life. Multiple layers of protection are employed at the chemistry, cell and pack level to achieve an energy storage solution with superior safety and abuse tolerance. (As with all batteries, charging should not be done unattended)

Life

• 10+ year projected shelf life, will not self discharge
• Industry leading cycle life – thousands of charge cycles
• Environmentally friendly chemistry
• Long life – in the field and on the shelf - Rechargeable lead-acid (SLA), NiCD, and NiMH batteries will “self-discharge” when sitting on the shelf. Some (such as lead-acid) can be damaged by long-term storage and rendered unusable. UV-PowerPaks will last years without use, and can be recharged thousands of times.

UV-PowerPak Specifications

2 hour Battery - A small exceptionally light pack with over 2 hours of power – rechargeable in 15 minutes. Lightweight - can easily be carried in a pocket. Two packs will provide an evening of lamping without even being aware that you’re carrying a battery – or use just one pack; it can be recharged in under ½ hour using your car/truck battery.

• Power: 2.3AH (amp hours) at 13.2vdc. Will power the average lamp for over two hours, longer with intermittent “lamp on” time. High constant voltage output insures maximum lamp brightness.
• Weight and Size: 12 ozs, 4 ½” x 2 ½” x 1” (a little bigger than a pack of cigarettes)
• Charge time (from a full discharge state): Under 45 minutes for a full charge
• Connectors: High current, high reliability Anderson Power Pole with locking connector (cigarette lighter connector adapter available). Auxiliary balancing connector assures full balanced charge of each cell.

4 hour Battery - For those who need more power, longer, the 4 hour pack is essentially two “2 hour” packs wired together. Over 4 hours from one lightweight pack.

• Power: 4.6AH (amp hours) at 13.2vdc. Will power the average lamp for over four hours, longer with intermittent “lamp on” time. High constant voltage output insures maximum lamp brightness.
• Weight and Size: 1 Lb, 7 ozs, 4 ½” x 2 ½” x 2”
• Charge time (from a full discharge state): Under 1 hour for a full charge
• Connectors: High current, high reliability Anderson Power Pole with locking connector (cigarette lighter connector adapter available). Auxiliary balancing connector assures full charge of each cell. (Inquire for SuperBright II connector).

Required Charger: For both batteries - Hyperion EOS 606i – Universal AC power (110v to 240v)/DC powered (12vdc car battery), quick charge, LCD status display, automatic cell balancing. Can also charge other types of batteries such as lead-acid, NiCD, and NiMH.

Optional Cigarette Lighter Connector – Adapts new battery pack connectors to lamps using old-style connectors. If possible we recommend replacing your old connector with the new style powerpole connectors.

HYPERION EOS 606I DP Charger

The EOS 606i DP AC/DC is a versatile, easy-to-use charger with special features for fast charging of 2.3AH and 4.6AH UV-PowerPaks – at home or in the field! It can also be used to charge many other types of battery packs. AC/DC operation allows charging directly from AC wall supply while at home OR from a 12V DC battery while at the field. LBA10Cell Balancer (included) insures proper cell balancing and long life.
(This charger is required to charge UV-PowerPak batteries – do not attempt to charge with any other charger.)

Specifications:

• Two INPUT power choices, power from home AC, or car battery
• Use AC 100~240V at home
• DC 11~15V anywhere
• 2 Line LCD for charge monitor and post data display
• Charge/Discharge (useful for cell balancing)
• 1-14 cell NiCd/NiMH Batteries
• 2-12v Lead Acid Batteries
• 1-5 cell Lithium Ion or Lithium Polymer Batteries
• Cell balancing - LBA10 included
• 0.1-5A Charge Current
• Audible Function Alarm
• Output Charge Cord/Connector set included ($4.00+ value)
• Double-length Input cord for convenience

Why LiFE Batteries?

• Light weight!
• Higher voltage, more lamp watts
• Constant power to the end of the charge
• Quick recharge (10 - 30 minutes)
• Reliable – thousands of charge cycles

Sealed lead acid batteries are fine if you’re starting a car. But they have inherent problems, as do other technologies. Over time an SLA battery will simply go dead. These types of batteries are not made for deep discharge, or for sitting on a shelf over the long winter months.  Life expectancy can be as little as 200 charge cycles – at best 500 cycles. And the worst thing about it is that you probably won’t even know until your light finally just won’t light (or the battery boils over during charging).

NiMH and NiCD are a little better, but come with their own set of problems. And they all take 8 to 10 hours to recharge!

This chart compares the brightness (actual watts, over 8 hour time period) of an 11 watt lamp powered by a 7 pound, 8AH lead-acid battery to a lamp powered by a set of two 4.6AH (9.2AH total) UV-PowerPak batteries (total weight of less than 3 lbs).

What is Cell Balancing?

12V battery packs are made by “stringing together” lower voltage individual batteries. A typical individual battery cell generates around two volts (on average). If you wire 6 of these cells in series you will get 12vdc (lead-acid for example). Some cells may generate only 1.2v, thus 10 cells are needed to get 12vdc (NiMH). Others may generate slightly more voltage, but the principal remains the same. Simply wire in series the number of batteries needed to get 12vdc.

Because of production tolerances, uneven temperature distribution and differences in the ageing characteristics of particular cells it is possible that individual cells in a series chain could become overstressed leading to premature failure of the cell. During the charging cycle, if there is a degraded cell in the chain with a diminished capacity, there is a danger that once it has reached its full charge it will be subject to overcharging until the rest of the cells in the chain reach their full charge. The result is temperature and pressure build up and possible damage to the cell. During discharging, it is even possible for the voltage on the weaker cells to be reversed as they become fully discharged before the rest of the cells resulting in (permanent) failure of the cell.

Because Lead acid and NiMH cells can withstand a level of over-voltage without sustaining permanent damage, a degree of cell balancing or charge equalization can occur naturally with these technologies simply by prolonging the charging time since the fully charged cells will release energy by gassing (getting hot) until the weaker cells reach their full charge. Usually this is not harmful to these cells unless the imbalance is severe – then heat can permanently damage a cell, or worse – cause a fire. Although the problem is reduced with Lead acid, NiMH batteries and some other cell chemistries, it is not completely eliminated and solutions should be used for most multicell applications.  Heat is a battery's enemy so we must do everything to limit this heat, but insure maximum charge.

Lithium cells cannot tolerate over-charging. The cells in the UV-PowerPaks are Lithium Ion and thus need some kind of balancing to prevent this from happening. This is taken care of automatically during the charge process by the Hyperion Charger and LBA10 Cell Balancer. At the end of a charge each cell in the battery pack will be charged to its optimum voltage, ready for an evening’s use.

A side benefit to this balancing procedure is MAXIMUM POWER (all cells are fully charged, doing their job) and longer life from your battery pack – both in charge times, and in simple longevity. A lead-acid battery with a discharged cell - at a minimum - will provide less runtime, and can risk cell reversal and ultimate failure of the entire battery. NiMH packs can heat up to a point where they might even catch fire if not protected by an over temperature sensor during charging. Intelligent charging and safe battery technology solves this problem and is recommended for all multi-cell applications – and is required for UV-PowerPak Lithium Battery Packs.

*****Important Note on the Use of LiFE*****

Do not allow your LiFE battery pack to discharge below 12VDC. IF the voltage drops below this point it could cause problems in recharging them (you might have to juice them up a little in NiMH mode before you can charge them properly in A123 mode). Even worse, discharging below 11VDC could permanently ruin one (or more) of the cells. Use the battery monitor and watch it while using your lamp. Switch packs immediately when your pack drops to 12VDC (or before). Once one of these packs starts to drop you only have a few minutes (15 to 30) to change packs out.