OT: Lead acid battery voltages, and battery maintainers

[Richard Fjeld-2]

There was a recent thread about lead acid battery voltages relating to K type radio usage.
I wanted to make mention that I had a lead acid battery last in one of my cars for 12 years without ever failing, and then I carelessly let it freeze up one harsh Minnesota winter.  I always wondered why it lasted when others seldom go more than four years.

So, I bought some digital voltage displays on eBay awhile ago, and I install them portably in each vehicle with a battery including tractors, etc.  I do this with an accessory plug wherever possible, to study what the charging circuit is doing to the battery.

I have found some very interesting things happening.  For example, my recently  new Dodge Caravan runs  around the middle of 14 volts.  In my tractor,  I have to keep the voltage below the gassing point by having the lights on. I was replacing batteries in the tractor quite often.  The list goes on, but is  of lessor significance.

A note about battery maintainers;
I have various types and brands. I have automatic charger/maintainers with their own quirks.   I bought some maintainers a few years ago from a popular supplier, and they were not automatic. They were  maintainers, not chargers.  I ruined two batteries with them before I made them dependable.

In the first battery failure, they had an electrolytic cap that was not rated  high enough for peak voltage.  It would fail and cause it’s circuitry to damage the battery. After I found the cause, I replaced the caps in all.

The second battery failure was due to a circuit breaker tripping for who knows why. It went undiscovered for too long.  The maintainer had a LED that was powered from current flowing in the circuit, now from the battery.  Though slight, the drain took down the battery.  I placed a diode in line with the lead to the battery in each  to prevent current flowing backward.  It causes a drop in voltage, but they were a bit high to begin with. They have since been dependable for a long time.

FWIW,

Rich, n0ce


______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]