Residential fridges

[Don Bradner]

Pete, I note that in the past you've said similar things, and suggested they
were the reason your batteries were shot when you purchased your Bird.

Having purchased a new RV in the past with shot batteries I understand that is
not uncommon to find bad batteries at purchase. Salesmen are very poor at
leaving coaches hooked up, and they routinely run the batteries to full
discharge (10.5 volts or so); no battery likes that very much. Your coach sat on
at least two lots prior to your purchase, and that's a possible explanation, but
not charge voltages.

I think if you review the Link 2000 manual you will find that what you quote
below is AGM float at 120 degrees, and Liquid float at 70 degrees. Apples and
Oranges.

At 70 degrees, Wet-Cells are 13.5, and AGM 13.3. At 80 degrees they float at an
identical 13.1. Nowhere is there enough difference to damage an AGM with
wet-cell settings, and AGM manufacturers generally don't make strenuous pleas
for owners to have programmable controllers - the difference will at most be a
small amount of battery life.

Don Bradner
90 PT40 "Blue Thunder"
Posting today by satellite with AGM power in Quartzsite, letting the voltage
drop to 11.9 before charging (by choice)

On 2/6/2008 at 5:34 PM Pete Masterson wrote:

>Nope... AGMs must be charged at a lower voltage to avoid damage. I
>note that the Link 2000R would float at about 13.5 volts with the wet
>cell setting, but floats at 12.9 volts with the AGMs. (The charging
>rate is preprogramed -- you simply (well, it's not _that_ simple) set
>the kind (wet, AGM, gel cell) and the battery size (amp hour rating)
>into the controller and it chooses to do whatever it is it does.)
>
>The dual inverters in my coach have 4 breakers that control what they
>serve. I've not gone to the trouble to figure out what each breaker
>serves individually.
>
>I can see the advantage of having a smaller, true sine wave (my
>inverters are modified sine wave, which is less efficient for the
>refrigerator) dedicated to the refrigerator.
>
>While parked in Oregon, I checked temperatures in the refrigerator
>during the day (when the generator was unusable) and it took about 6
>hours for the interior to get into the 'danger' zone on the
>refrigerator thermometer I use.
>
>Pete Masterson
>'95 Blue Bird Wanderlodge WBDA 42
>El Sobrante CA
>aeonix1@...
>
>
>
>On Feb 6, 2008, at 4:56 PM, Ross MacKillop wrote:
>
>>
>> Hi Pete,
>> Aren't the charger settings for AGM the same as Lead/acid.? (not
>> like Gel)
>> The new 450 LXi has a single smaller inverter for the fridge (1500
>> true sine wave.) I turn the 2, 3600 watt ones off and turn the
>> fridge down(really up) for night.
>> Ross
>> Palm Desert
>> ..<snip>