Battery Charging Question
 

The Concord RG is a AGM (absorbed gas mat) lead acid battery that needs a special charger. All AGM batteries need to be charged with a charger designed for them. I believe if the charger is pushing more than 14.5 volts it should not be used. I'm going by memory here so no flaming for being a 1/2 volt off. :p

This is the type of charger I'm talking about. They are a good investment as you can use them as battery conditioners (desulfating) on all types of 12V batteries.

http://www.vdcelectronics.com/

A buddy of mine has a Black & Decker that does the same thing for $60.00 at Home Depot or Walmart.

Is a AGM the same as a VRLA? Concorde says this is a VRLA:
http://concordebattery.com/flyer.php?id=36
Do you have the model on the B&D?
Thanks

I also am interested in learning the model of the Black and Decker.

Google took me to: http://www.blackanddecker.com/Produc...Path=4010.4013

http://www.lanescarproducts.com/blac...y-charger.html

May be a better price with more searching.

If you read the bullets on the description is says AGM, granted I'm assuming it is AGM by that alone. Maybe be worth a phone call.

The charger you need for the Concorde RG35A (or any RG Concorde) is: BatteryMinder Model 12248-AA-S1



I just did all the research -- talked to Concorde direclty -- this the only one they recommend.

This is the aviation specfic unit -- you can find it at :
http://www.advancedaviationproducts.com/aaphome.html

(I just bought one today!)

Dave T.
Lancair Legacy

YOU MIGHT LOOK AT THIS........
 

Acronyms!
 

(AGM) absorbed class mat
(SLA) sealed lead acid (sometimes maintence free)
(FLA) flooded lead acid
(VRLA) valve regulated lead acid (just the vent technology)
(GelCel) (different technology than AGM)
(RG) Recombinant Gas (why it can be sealed, but will vent of overcharged)

There's some overlap & name dropping, but the main "technology" is the AGM part (I think some use interchangeably with SLA correctly or not). The RG-25XC spec does say AGM specifically, as well as VRLA and RG for bragging. So this battery is like a Odyssey P680, an AGM battery. The main "technology" is the AGM part, which also are RG and have VRLA.

All batteries need some kind of pressure relief. VRLA means some kind of valve verses no valve at all, just a vent. AGM should not vent any gas unless it gases off due to massive overcharging for extended time (volts over 15). So the vent is closed but the valve opens when needed. AGM does have lead plates and acid, just suspended in mats verses sloshing around as a liquid or gel, so VRLA is just fancy talk.

AMG batteries need a special charger if you want automatic charging, set-it & forget-it. YOU CAN USE A PLAIN CAR CHARGER WITH CARE. You have to time it and manually disconnect the charger; you can't leave it on for too long or you'll damage the battery.

For example at 11.5 volts a AGM is considered 100% discharged. You need a charger of about 10amp for a PC680, suspect that's fine for a RG-25XC. The max charge time with a 10amp charger is 2 hours for the P680. If the battery is not fully 100% discharged, than you need to reduce charge time, may be a lot, like 10-20-30 minutes. Overcharging damages the battery. The 100% charge voltage for a AMG is around 12.84 volts ideally, but you want to see at least 12.6 volts or more after you disconnect the charge and manually measure open voltage. You need a 10 amp charger or larger. Charge times are much much less with a larger charger. You need at least 7 amps I recall for the PC680 sized battery to get full charge. Volts under 14.2-14.3 will not fully charge a Odyssey AMG battery.

The fancy chargers designed for AMG batteries have 3 stage logic. Odyssey explains this in great detail on page 12 of their tech manual:

http://www.odysseybatteries.com/files/techbook.pdf

Not all chargers for AGM are the same. They all might work OK, but some may have more logic and protections, including temp compensation. Just be aware of what your AMG needs to rapid charge (constant current), absorb charge (constant volts) and float. Don't overcharge it or connect it to a float charger in a discharged state, neither are goodness. One results in battery damage and one just does not help much.

If you use a new charger you have to watch them to see how they're programed, or ask the manufacture if its not spelled out like the odyssey tech manual describes.

Personally I'm not a big fan of leaving electical stuff connected in an unattended hanger, especially charging batteries in the plane. Its also against local fire code (and you insurance?). Extension cords and/or charging unattended batteries have burned hangers down before. If the battery has an internal failure or the charger fails wide open it could get HOT. A little 1.5 or 3 amp trickle charger may be safer, but they will not fully charge or condition a AGM battery. AMG batteries have very good shelf life. If your battery can't take a week or more sitting, than you need to replace it. It should be fully charged after a flight right. Your planes charge system needs to be at least 14.2-14.3 volts at the battery.

CHARGERS
Here is a nice charger: http://www.thebatteryminder.com/12vb...nder-p-58.html or LINK
It even has battery temp compensation if you want (fancy fancy but cool). Not used one but this does seem to be a true three stage charger. It does say not for aircraft batteries but they sell a line of "aviation chargers" which are more expensive. A Odyssey P680 is a Harley Davidson/BMW motorcycle battery so it should be fine. Here is another 3 stage charger: http://www.samlexamerica.com/product...roductsID=8056

Schumacher Chargers: LINK. These models: SC-1000A, SSC-1000A, SC-1200A, SSC-1500A and SC-2500A have a AGM selection and are in the 10-25 amp range. Can't verify how good they work charging AGM, not tried them, but they do make good chargers; I'v got one of there basic ones. These SC or SSC chargers go for about $50 to $80.
http://store.schumachermart.com/batt...-chargers.html

I just bought a SSC-1500A from ebay for less than $50 with shipping. I need another charger anyway.

One last one is this: http://batterytender.com/product_info.php?products_id=2 (5 amps max is less than the 6 amps that Odyssey recommends for the P680 but I am sure it work. Looking at their tech info it sounds like they know what they are doing. They have a whole line of little battery maintainers (trickle chargers) which would not charge the battery fully but might work well for maintaining a fully charged battery.

If you leave a generic trickle charger on any aviation battery it will kill it!

It shortens the life by about half!

Using the charger i mentioned above will increase your battery life by a factor of 2 or 3. Expect 3 to 5 years on a Concorde if maintained with one of these.

(This is what all the manufacturers have told me of both batteries and chargers.)

dave T
Lancair Legacy

New Info
 

Actually the BatteryMinder Model 12248-AA-S1 is designed for any Concorde or Gill aviation battery.

as far as i know its the only one the manufactures endorse.

dave t.
lancair legacy