BackBlast's research and musings

Over a long term emergency when it is unreasonable to get buy with once-charged eneloops and single use primary cells, you must recharge your batteries.

On the low end, you can purchase this.



link

It is a one unit solution for off grid recharging. It's a nice small package, but it is very slow at recharging. The recharge won't be as healthy for your long term battery longevity as a more controlled careful charge. But in a short term emergency or where space is very limited that's probably a lesser concern.

The next option for higher volume and better charging is a 12v system/charger. Which is most any charger that comes with a vehicle adapter, and a power source be it your vehicle, or solar, or other off grid power generation system.

A vehicle system is convenient, because you likely have a tank of gasoline, and using a tank to just charge batteries will last you months and months to possibly a year or more. You can use it to charge your cells all you need when you need your cells (without starting your car), and once a week you'll need to run your car for 20 minutes or so to fill the car battery back up. This can be made more precise if you can monitor your car's battery voltage and minimize your car's run time/gasoline and insure the voltage returns to the right level.

A solar power option is to buy a small panel, 10-15 watts, and plug your 12v charger directly into the panel. No battery is required, but you can only charge while there is sun.

Now to the native 12v chargers..

Duracell 15 minute charger


This charger requires lots of power, so you probably can't run it straight off a small solar panel (at least if you want to populate all 4 slots), but it is oriented more for convenient quick charging, this is likely to work well in a vehicle operation.

15 minute chargers are a little harder on cells than the best charging systems (10 Amps FTW! ), but they are quite sophisticated to be able to safely and reliably charge at those rates and I would say they are generally better than the dumb chargers, or even lower end smart chargers. They will not charge marginal cells. Quick charging is rather hard on cells too and marginal or poor quality cells may die very quick deaths.

Maha C9000



This is a good smart charger that will give you some information about your cells (battery nerds like me like info...). This product gives you a lot of care options for rechargeable cells. Cycling, breaking in, discharging, and charging options to help you get the most performance out of your cells. It can also help you match cells for use together and weed out poorer cells early out of packs for those devices needing multiple cells (radios, etc). It runs off 12v, but does not come with a vehicle adapter or other 12v plug - which would need to be created for easier off grid use. This is a good option to get the most out of your batteries.

Available at Thomas Distributing http://www.thomas-distributing.com/m...ry-charger.php for $50.

Another route that's possible, and you should be aware of, though not ideal. Is the ability to run any charger off a 12v system through an inverter and it's own power adapter. The inefficiencies eat your power faster than the direct 12v chargers, but it does work.

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