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Charging system reply
Yahoo Message Number: 23523
Dave: The biggest difference between AGM and the Trojan batteries supplied by LD is that venting isn't needed for the AGM batteries. You already have a vented location and the regular 'wet cell' batteries are less expensive. I'm not sure if the present LD converters are compatible with AGM.
110v. AC from the generator is the same as 110v AC from shore power.
Since the coach 12v. needs are supplied by the converter, only a small 'trickle' charge flows into the battery. Smarter converters in newer coaches provide more current if the battery is more discharged and taper off as the battery becomes charged. A separate charger can provide more charging current, but at a greater amount of involvement. A solar panel will charge the batteries if nothing else is. If you were plugged in, running the engine and in sunlight, the scheme with the highest voltage would do the charging. All of this is automatically switched.
The inverter from LD is packaged with the entertainment center. I believe it isn't offered any other way, because people would want different wattage ratings for different uses. LD doesn't want to get involved with that.
Ron and Bluebelle, '99 23.5 TKB

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RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB
Re: Charging system reply
Reply #2 –
Yahoo Message Number: 23532
Quote
The modern converter has only one output, 12V (actually about 13.7) at 45 amps max.  What the coach does not use goes into the batteries until they are charged
I have reservations about your explanation - this would be a poor way to supply the coach appliances, if true. Modern high-end battery charging sections of converters provide an active multi-stage charging output for the batteries. They do not rely on any self- regulating by the batteries themselves. This would supply poor voltage regulation to the light and appliances in the coach, were there only this one output. What would make more sense is to separate coach 12V supply from the battery charging duties, as with older designs. Just the 16-17V required for equalization would destroy many appliances and most of the light bulbs.

Traditional converter designs have used a series current limiting resistor fed from an unregulated supply for battery charging. This both limits the maximum charge current AND allows for too high a latent voltage for safe trickle charging. With active loop control on the charging function, newer chargers are only limited in current by the unused capacity left over from running the coach.

Steve
2004 FL
2013 Honda Fit
Re: Charging system reply
Reply #3 –
Yahoo Message Number: 23534
Quote
The modern converter has only one output, 12V (actually about 13.7)at 45 amps max.  What the coach does not use goes into the > batteries until they are charged

.... this would be a poor way to supply the coach appliances, if >
true ....

Unfortunately, it is true.  The Magnatek 7300 converter, while a drastic improvment over previous designs is not a particularly good battery charger.  The unit installed in LD coaches has a fixed output of 13.8 volts applied directly across the batteries.  When turned on with a low battery it will initially provide about 40 amps of current (as measured by my battery monitor).  This quickly falls to the mid twenties and lower as the battery takes some charge.  In terms of your message, it does not qualify as a "modern battery charger".

The 13.8 volts is too large to float the battery in the summer for any extended period of time but it works OK in the winter (see earlier posts).  I have installed a toggel switch in the converter's AC power supply so I can turn it off without using the breaker.  One of the outcomes of this was to note that the genset uses about 4 amps of current from the coach battery when it is running.
 The Magnatek 7300 is a vast improvement but it is not what one would call a "good" battery charger.  As an electronics designer, I keep seeing that it would be relativly easy to add that capability to the unit but they chose not to.

Linley
Re: [Life With A Lazy Daze RV] Re: Charging system reply
Reply #4 –
Yahoo Message Number: 23535
lfgcfg gumm@...> wrote: The Magnatek7300 is a vast improvement but it is not what one would call a "good" battery charger.  As an electronics designer, I keep seeing that it would be relativly easy to add that capability to the unit but they chose not to.

Lazy Daze told me that they use a Parallax 7345 converter, which is a solid state unit that uses a two stage battery charger.  Is this significantly different from the Magnatek charger?

Dave

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Re: Charging system reply
Reply #5 –
Yahoo Message Number: 23536
Quote
lfgcfg  wrote: The Magnatek7300 is a vast improvement but it is not what one would
call a "good" battery charger.  As an electronics designer, I keep seeing that it would be relativly easy to add that capability to the unit but they chose not to.

Quote

Lazy Daze told me that they use a Parallax 7345 converter, which is
a solid state unit that uses a two stage battery charger.  Is this significantly different from the Magnatek charger?

 Same animal - Magnetek has divested itself from RV products.

This IS spec'd as a two-stage charger by Parallax though. Since the only way this can be accomplished is to change the output voltage, or switch the batteries out to a separate circuit, do the lights dim? How does the charger know whether it is supplying 30A to the batteries or to coach appliances with only one output? Does it continually switch in and out of its 'stage 2' mode as the water pump cycles on-and off? Something doesn't add up here. Either it is really a one-stage charger, or it must have a separate battery output with switching.

Steve
2004 FL
2013 Honda Fit