I happened to notice tonight that if you have an S2 (pre-2013?) BatteryMinder (raises hand...), VDC Electronics offers an $86 upgrade to the new-and-improved S5 for the US and Canada.
Apparently the S5 version is better for our Concorde RG batteries than the S2 version, per the quote below.
Naturally I bought mine just before they transitioned from the S2 to S5.
Chris
BatteryMINDer upgrade offer page wrote:VDC, the makers of the BatteryMINDer®, worked closely with Concorde Battery Corporation's engineering to develop the new 12248-AA-S5 and 24041-AA-S5 Charger / Maintainer with optimal charge and maintenance voltages for Sealed AGM RG® Series batteries. Concorde conducted extensive testing to determine the ideal float voltage for optimal battery performance with extended battery life. The new settings are incorporated in the S5 model. Long term float testing comparing the S2 and the S5 revealed that the S5 setting maintained battery capacity at 100% State-of-Charge (SOC), whereas the S2 maintained battery capacity at only 85-90% SOC.
Customers who already own the S2 and desire an upgrade to the S5 can send their units back to us to be converted.
How: Fill out the form and send it with your BatteryMINDer® unit and payment. Please allow a minimum of 10 working days from the date we receive the unit for us to ship the modified unit back. This does not include shipping time. This offer may be withdrawn or amended without notice.
For what its worth, I have a pre-2013 (which has options for selecting battery type and charging current) and the new "Concorde friendly" version (which has no options). I have one in each hangar where each one maintains removed Concorde when I do not have IT desulphating the one in my DA40 when it is parked there.
I have no doubt about the claims that the new charger more accurately reflects the theoretically perfect float voltage as specified by Concorde. This said, it is useful to keep a few things in mind before you rush out to buy a replacement:
- The old/new float differential is around 0.3 V or less (I don't have access to my specs; perhaps someone has the actual number handy). If you compare this to the float variance of the onboard regulator and the error term of each (charger and regulator), the difference gets pretty close to noise.
- When I measure the actual battery float voltage, I do not see a consistent difference between the two chargers.
- I cannot detect a difference in how well each one maintains the batteries (this doesn't mean much because it is an 'n' of 1)
- The new charger/desulphator is definitely more likely to reject a perfectly useful used battery as defective. it rejected and would not charge either one of my 5-year old removed batteries (lights red) that the old charger accepted and returned to target values within about 45 days of desulphating. After that period, the new charger/desulphator would accept and maintain the old battery. If nothing else, don't trade in your old charger.
The new charger may be a bit more "perfect" but it also has some disadvantages and the old charger works very well and has some advantages. Some of what your are reading and hearing has to be driven by marketing and sales; i.e., how can we get all of our customers to spend some more money with us. Knowing what I know now, if I had two old models, I would keep them because of their increased versatility in battery types and tolerance for batteries that need to be reconditioned. The BatteryMINDeer people will have a different take on this.
With a little interpolation, here is the difference between the stable (no charge/discharge activity for four hours) open circuit Concorde AGM RG Series voltages by percent of charge.
The methods specified in the instructions are 1) directly connected to the battery terminals, or 2) connected to the battery relay. The second method is what I did on my aircraft.
