18650 Li-Ion Backcountry system (batteries not included) $44.95:
Here's a possible scenario:
You are taking off on a multi day ski tour with some friends for 5 days. It starts with travelling a logging road, then skiing to a hut. The hut has solar power. During the day you will be using your radio so you need lots of battery capacity. You are taking along a Spark SX5 Headlamp as your backup light. You want to go as light as possible, and do not want to carry a whole bunch of different battery types. You' like to be able to charge your batteries at home, at hut, and in your vehicle. You want to use your radio while in your vehicle to monitor and talk on the logging road without running your radio batteries down before you start to ski tour. The 18650 Backcountry system was designed for situations such as this, and many others. If you don't have solar power, then you can carry more inexpensive rechargeable batteries as backups and enjoy the fact that Li-Ion chemistry is the lightest you can carry for the amount of power you get.
With this pack you will always get the maximum transmit power of your radio. The weight of this system is about the same as 2 1700mAh Wouxun packs. The cost is also the same. So if you are just day tripping this system is not an advantage. However you need to consider you cannot power your headlamp or charge your other devices with the Wouxun battery pack. You cannot plunk cheap extra cells into the Wouxun pack when the first set dies. However, three of the very best 3400mAh Li-Ion cells have double the capacity of the Wouxun 1700mAh packs at half the price. So when your circumstances dictate you may need more than 2 Wouxun 1700mAh packs, this sytem makes more sense both in terms of weight, and cost.
The battery holder that you see in the middle has a protection circuit module that allows you to safely use unprotected 18650 cells. It will act as a power pack to run your radio, and it will act as a charger to charge the cells from a 12v auto plugin, or from 110v mains power with the inexpensive optional AC-DC adapter. You can carry your headlamp with no batteries to save weight and use one of the cells from this pack if you need the headlamp. If you do not have any charging source for your trip, by using 3400mAh 18650 cells you get the equivalent of 2 of the Wouxun 1700 mAh extended battery packs. If there is Solar Power at the hut, you do not need to pack in the dropin charger in order to recharge your radio every night. During the day if you are using the radio to talk to your tail gunner, base, or other group, the coiled cord allows plenty of length the carry the radio in your pack or on your hip and use a speaker Mic mounted on the pack strap for convenient use of the radio at anytime.
The 18650 battery holder has a quick connect that allows it to detach from the 12v battery eliminator, so the eliminator can be used in your vehicle without the battery holder.
Usage Notes: We have added epoxy to the wire connection points to make the connection more robust and less likely to break off, but we recommend carrying it in something like a tupperware container when possible. The positive terminals on 18650 flat top style batteries vary in form factor depending on brand. With some they do not make contact with the contacts in the battery holder very easily, so you need to move the positive end around until you see the radio power on. Never depend on just one system when communications may be vital, have an alternative backup such as a 1300mAh battery pack just in case. At least 2 members of every ski party should have a radio, and one of them is never exposed to avalanche terrain at the same time as the other.
