[1/29/2012] Reviewed by: Kent Shaw
Applicable to: '90 - '97 '99-'05 '06+ 1.6 liter 1.8 liter
Our 1999 Miata has lived a pampered life ever since we bought. It stays in the garage and is usually only during warm perfect summer weather. It only recently passed 24K miles on the odometer. This low usage, however makes it very difficult to keep the battery fully charged and ours usually only last a couple of years before they no longer keep a charge and have to be replaced.
Recently I ran across this charger which also claims an ability to recondition weak batteries through a unique process called desulfation. The BatteryMinder 12248 is all solid state and much lighter than many of the brute-force charges that you often see. This model of the BatteryMinder product line has a lot of sophisticated features:
- It uses a temperature sensor which can be attached to the battery to assure that the battery is not overcharged and that the water in the battery is not boiled off during the charging process.
- It offer 3 selectable rates of charging (2/6/ and 8 amps).
- It has unique charging algorithms based on the type of battery: flooded cell, AGM, or Gel. [Warnings in the instructions say that you can shorten the battery life by selecting the wrong battery type].
- It uses the desulfation process during the charge to dissolve the sulfation crystals which occur naturally as the battery becomes discharged. Sulfation of the battery can eventually make it stop working.
- You cannot overcharge the battery.
- The charger can be used for all 12 volt acid batteries except for aviation batteries, which have a different charging cycle at a lower charging voltage. BatteryMinder has another product for the Concorde and Gil aviation batteries.
Operation is simple. Connect the battery to the charger first, before plugging it into the wall. If the cables are connected properly (i.e. positive to positive post on the battery) and the minimum voltage on the battery is 11 volts, you will see a green light indicating that the battery is ready for charging. If the battery reads lower than 11 volts, then there will be a red light and the battery will not be charged. When the charger is plugged it, the power light and the charging light turns green. When the battery is fully charged, the charging light will blink and the charger then goes into a maintenance mode and you can just leave the battery (or up to 6 batteries connected together) until they are needed. If a battery is really hosed, the instructions recommend charging the battery several cycles until the voltage readings stop increasing with each cycle.
This device gets extremely high marks in every review that I have seen and there are many antidotal remarks where this charging unit has resurrected batteries that were believed to have been dead. These features and performance come at a price. The list price is around $160 but you can buy it through Amazon or other discounters for about $108. The extra battery life will likely offset this higher cost over another charger. If you do not want to spend this much for this particular model, then look at the BatteryMinder model 2012 available with the same features but 2 amps only.
Only recently acquired it but favorable impressed so far.
Not an installed item