Testing trailblaza fridge
Submitted: Thursday, Mar 03, 2005 at 13:13
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Pyalong
Hi all,
I have just completed a bit of a
test on my 12 month old 60 litre trailblaza fridge, after getting the wiring redone from the battery to the fridge, using a fully charged normal 12v lead acid battery(auxilary) , in a 80 series l/cruiser.
The only item I had in the fridge was a slab of vic bitter (still in the carton), the fridge lasted for approx just under 29 hours before it could not gain enough power to run its motor. The fridge temperature ranged between -4 deg and +7 deg, with the daytime outside high temp of around 21 to 22 deg. The car was out of the sun for most of the day.
My question is....Is this a reasonable time I could expect this fridge to operate for, without running the engine at all?????.
Cheers,
Mick.
Reply By: Member - Jeff M (WA) - Thursday, Mar 03, 2005 at 13:56
Thursday, Mar 03, 2005 at 13:56
What type/size of battery!?
How do you know it was fully charged? Was it charged off a 3 stage charger or just off the alternator? What was it's voltage at rest before you put a load on it?
29 hours is not a Heap of time for a good compressor fridge running on a good battery. Hell I can almost get that out of my Evil sooped up cooler!
But it all depends on the batterys!
-4 to +7 seems like a HUGE range in temps?? What's going on there?
AnswerID:
100962
Follow Up By: Nudenut - Thursday, Mar 03, 2005 at 14:14
Thursday, Mar 03, 2005 at 14:14
differential seems a bit high but should give a product temp of around 1.5c.....nice cold necter of the gods
FollowupID:
359020
Follow Up By: Pyalong - Thursday, Mar 03, 2005 at 14:16
Thursday, Mar 03, 2005 at 14:16
Thanks for the reply Jeff,
I have NFI about batteries really....but it is 670CCA, 16 plate, RC 140, could it be possible the RC 140 means amp hours??...buggered if I know.
I put the battery on a charger (dont know the type of charger) overnight. The volt meter on the fridge read 14v before I turned the fridge on...but I wouldn't punt my house on the reliability of this particular meter. The temp range was actually -4 to +4...typo on my part, so that is whats going on there!!...lol.
Cheers,
Mick.
FollowupID:
359022
Follow Up By: Member - Jeff M (WA) - Thursday, Mar 03, 2005 at 14:23
Thursday, Mar 03, 2005 at 14:23
Ok, so it's not a bad size battery, albiet not a monster either. That's a pretty cold setting to have it on so it's not toooo bad on the battery usage. What was the ambient temp? Was it locked up in the car while it was running or did you leave windows open etc?
Considering it was keeping a carton of bleep pretty cold it's doing ok. RC 140 would not be amp hours.
The volt metre would have been registering 14v probally because you had just taken the battery off the charger and the batteries voltage wouldn't have stabalised yet. How old it the battery? Has it been flattened a lot?
FollowupID:
359025
Follow Up By: Pyalong - Thursday, Mar 03, 2005 at 14:33
Thursday, Mar 03, 2005 at 14:33
Jeff, the battery is less than 12mths...just had it checked by auto elec, and it came up trumps. I used it for the fridge 6 months ago for a 2 month camping trip, and it did get down on volts a few times...also for 3 or 4 short trips since, and has also been down a couple of times.
The ambient temp was around 21 to 22 deg, car in the shade, but all windows/doors locked up, to give it a good
test.
Thanks for the tip on the RC...I probably would have sounded like a d/head...running around saying I had a 140 a/h bat!!!
Cheers,
Mick.
FollowupID:
359026
Follow Up By: Member - Jeff M (WA) - Thursday, Mar 03, 2005 at 15:23
Thursday, Mar 03, 2005 at 15:23
Well I reckon that's ok, the ambiant temp inside your vehicle would have been up there after 24hours of running a fridge keeping a carton of beer at 0c.
Just don't flattern that bat too much as it won't like it (no battery really does). Try not to let it get under 11.5v.
FollowupID:
359028
Reply By: Mainey (WA) - Friday, Mar 04, 2005 at 00:43
Friday, Mar 04, 2005 at 00:43
Pyalong,
the figure RC140 referrs to the 'Reserve Capacity' of the battery and is an extremely decent number, even compared to Deep Cycle batteries, so what battery is it ??
You have stated "The fridge temperature ranged between -4 deg and +4 deg, with the daytime outside high temp of around 21 to 22 deg. The car was out of the sun for most of the day"
That is a very large temperature range and in normal use would equate to the fridge running far to cold and hence drawing too much
battery power, a figure of a minium of +1 degree and a max of +4 degree's would be ideal, as it would give you far better battery performance and the contents would be still very nicely chilled.
World Health Organisation and indeed most health authorities specify +4 degrees as absolute _maxium_ for safe food storage, and to have a temperature range that achieves +4 degree's but then goes down into the minus numbers you are only wasting
battery power! the temperature sender should be looked at to achieve zero or better still +1 degree, with a _maxium_ of only +4 degree's.
With the fridge filled with food and drinks and the contents pre-chilled, run the
test again I think the result would be slightly better.
AnswerID:
101063
Reply By: Wok - Friday, Mar 04, 2005 at 07:54
Friday, Mar 04, 2005 at 07:54
Mick,
[duty cycle @ ambient temp] X [running hrs] X [average compressor draw] = [Ah used]
1/4 X 29 X 4.5 = 36.625Ah
Conclusion: low battery
Temp figures are not comparable because it depends on position of sensor & themostat eg if your sensor is located just below the top lip, your range is ok; if it is midpoint...it ain't good.
cheers
If this is double posted...It ain't my fault......the first attempt was aborted by the server!
AnswerID:
101076
Reply By: Pyalong - Saturday, Mar 05, 2005 at 20:32
Saturday, Mar 05, 2005 at 20:32
Thanks for the input guy's....food for thought..and another
test...Ta.
Cheers,
mick.
AnswerID:
101248
Follow Up By: ozi explorer - Sunday, Mar 13, 2005 at 16:36
Sunday, Mar 13, 2005 at 16:36
Hi Pyalong,
Some more food for thought......as I have the same TB, but a bit older but still workin a treat have done some testing myself.
First of all I run mine off a 105amphr DC batt (from USA) but have just upgraded, to hopefully better 105 Voyager Aldeco Marine batt, so still to
test out that to its extent. Am not sure on the hours of the last batt running the fridge but am sure it far exceeded 29 hours full of all food types and having the shelf 1/3 up from bottom for freezing as
well.
The other testing and results are on Post:20811 then read onto Post:21177, will be very interesting for you!!!
milo...
FollowupID:
360018
Follow Up By: Pyalong - Monday, Mar 14, 2005 at 12:31
Monday, Mar 14, 2005 at 12:31
Milo,
Good on ya
Milo, thanks a ton for that info...bit strapped for time at the minute...but will certainly...check it out later in the week.
Cheers,
Mick.
FollowupID:
360095