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Battery Charger/ Tender Help

UH1CW2

Well Known Member
Over the last 12 years I have gone through 2 Odessey 920 batteries, 1nd 2 Concord 35ACX Batteries. I am looking for a battery tender / charger that will prolong the life of these expensive batteries. Does anyone have a proven unit that is under 200 dollars. The battery tender I was using up until a few years ago was a cheap unit (under 30 dollars) that may be the reason I went through so may batteries? Who has a suggestion for a Concord sealed battery that works by maintaining the batteries life over 3 years.
 
What battery or batteries are you "maintaining"?

Search for Oddysey battery failures on this site, and you may find that there is a consensus developing that leaving a battery on a "tender" or a "trickle charger" for long periods actually causes early failure.

If you fly your plane once every two weeks or so, and if your charging system is producing the correct charging voltage for your battery, you shouldn't need a Tender.

If you go long periods between flights, it may be better to charge the battery only just before you use it, rather than keeping it on a trickle charger.

I think the failure mode is called "Surface Charge", wherein the battery has the correct voltage under a light load, but fails a load test.

Lots more on the forum from folks much smarter than I am.

Flame suit on! :rolleyes:
 
Perhaps I don't have the right expectations, but I consider 3-4 years from a AGM/Lead Acid battery about par. I end up replacing them in my cars and trucks at the 4 year mark, almost to the date(out of necessity), and I got just under 4 years out of my Odyssey PC680 Battery. Replacement cost was $112 shipped. Should I expect more? Probably depends on the climate you are in and the frequency that you fly.
 
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Some battery tenders SHORTEN the life of batteries. I suggest that a battery tender be connected for only a short time, not connected continuously.
 
As others are saying zero dollars will be your best deal. I'm replacing a no-name AGM battery this annual that's been in my -4 since Nov of 2011. I did a capacity check on it and it's still at ~65-70% of original capacity, and this plane has been flown an average of around 7 hours a year during this battery's life.

AGM batteries will go for literally months without recharging, as long as you don't have 'vampire' circuits sucking on them while the plane is inactive. On the other hand, constantly hitting them with charge cycles, especially if the charger isn't really intelligent, is needlessly going through their 'cycle life'.

Charlie
 
Thank You for the advise

I have decided that I am not going to drop another 230 dollars on a battery tender. I will follow the advice of the group and not put the battery on a tender at all. I believe that the tender is the issue I am going through so many expensive batteries. I do expect to get between 5 and 8 years from a battery. 3 years is not acceptable for a Concord or an Odessey. Thanks Gentlemen.
 
My RV-3 has an 11 year old Concorde RG AXC type. Still works great. It has never been on a maintainer and went a year or two with only 2 hours per year it before I bought it. I have hooked up a charger when testing avionics but never a continuous trickle charger.
 
What is acceptable?

I have decided that I am not going to drop another 230 dollars on a battery tender. I will follow the advice of the group and not put the battery on a tender at all. I believe that the tender is the issue I am going through so many expensive batteries. I do expect to get between 5 and 8 years from a battery. 3 years is not acceptable for a Concord or an Odessey. Thanks Gentlemen.

Keep in mind the definition of ?acceptable?. An old battery that has 70% capacity should still crank the engine, but if your design calls for and hour of power for the panel after the alternator dies, that 70% capacity may now be unacceptable.

For all my planes, two PC-625s for capacity (no backup batteries for anything), one replaced every two years as cheap insurance that design capacity is maintained. The pulled batteries go on to a second life in law tractors and such.

Carl
 
The pulled batteries go on to a second life in law tractors and such.
Hey, I how do I get one of those "law tractors"? That sounds like a useful tool! Is this for use on lawyers? does it plow or maybe just mow down those law types? Either way I want one! :p
 
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