[Stuart] On Saturday, a member of local law enforcement asked me what chargers I recommend for maintaining batteries in vehicles which are parked for long periods of time. Here is an expanded version of what I shared with him. Most people use fairly simple “trickle chargers” but investing in a more sophisticated desulfating charger will extend the service life of your battery and to some degree can even recondition an abused / damaged battery (the reconditioning is not instant, you have to give it a long period of time to work). In my opinion, having the ability to recondition damaged batteries will be a valuable ministry during hard times. I like these particular chargers for a variety of reasons and have been using them on my vehicles for years. These chargers will handle parasitic drain well (up to 2 amps) so should be no need to disconnect the battery from the vehicle under the hood while it’s parked even if there are small, continuous loads like the clock, alarm system, etc. They also have temperature compensation to charge at the proper voltage even when it’s very cold out. NOTE: these chargers are only for lead-acid (flooded, VRLA, sealed, AGM type) batteries – NOT for lithium chemistries. The following two chargers you would leave connected continuously to your vehicle when it’s parked, especially for long periods of time. This is not something you connect up every once in a while and otherwise leave the battery sitting disconnected, if you want the maximum benefit (and maximum battery service life).

 

I especially like this version with the OBD2 connector because you can just plug it in under the dash (on any newer vehicle with an OBD2 connector), no need to mess with raising and lowering the hood to connect/disconnect the battery. I put the charger body underneath the vehicle under the driver’s door and just run the cord in through the bottom of the door. This makes it easy to see the charger and quick to disconnect it if you want to drive away in a hurry.  Learn more >

 

If you want regular alligator clips instead of the OBD2 connector, get this version (this is if you want something flexible that will hook up to any battery, or batteries in older vehicles without an OBD2 connector).  Learn more >

 

I use this charger to maintain larger battery banks, and it would be also appropriate for floating a battery system used to feed a base station radio (ham VHF/UHF, GMRS, etc). You can also use it on your vehicles. The difference is that it has selectable amperages up to 8A, and a battery chemistry selection e.g. to handle LiFePO4 (lithium iron phosphate) batteries (and is consequently more expensive).  Learn more >

 

This lower-amperage version would be appropriate for smaller ATV / motorcycle / generator starting type battery maintenance, and for maintenance of batteries not connected to a vehicle. (You can also hook this up to a vehicle, and there is an OBD2 connector version available, but personally I prefer the models 2012 or 128 listed above for vehicle connections due to their clearer indication of battery and load state.  Learn more >

 

Pro tip: if you don’t do what I described above (about placing the charger where it’s easy to see), and instead hook up the charger under the hood with the charger under the passenger side of the vehicle, and also forget to tell your wife….

expect that the vehicle will get driven with the charger still connected. 

(After this I realized the wisdom of using the OBD2 connector, because it’s very easy for the driver to see that the vehicle is plugged into something.)

This company (that makes the BatteryMinders) also (at least when I last called them a few years ago) still has a proper telephone support line that’s answered by a dude in the US with an American accent who has actual knowledge and can answer very specific technical questions.  Learn more >