High Battery Temp

KWC · 08-28-2010, 04:04 PM

I have a "09" Winnebago Tour. I am having a hard time keeping my coach batteries charged while hooked up to shore power. I get a "Charger-Off Batt High Temp" on my Iverter remote Panal. I relize the settings are to turn the charger off at 122 deg. and reset back on at 113 deg.

It started this summer while on the road, but it was 100 deg. outside and my basement A/C was blowing its hot condenser air near the battery compartment. I accepted it as poor design.

Today it is 85 degrees outside, I have no A/C on but the charger is off due to high battery temperature. The batteries are not hot.

My Dealer says he is familure with this issue and it is a Winnebago problem. The Dealer says they have no fix for this situation.

Has anyone had this issue. Does anyone know of a remedy for the Battery High Temp problem.

CaptBill · 08-28-2010, 07:18 PM

Have you checked the water level in the battery cells? If plates are exposed, you may have a shorted cell, resulting in a high battery temperature, and that could result in a battery bulging and/or explosion. Worth a look.

dengraham · 08-28-2010, 07:34 PM

KWC,
I would sometimes get the same high temp message. I have an 07 and the tires supply the heat especially in hot weather. I would pull out the batteries to let them cool and the inverter would finally kick in. I have even cooled them with water (on the outside) just to cool them down. I have heard of some people disconnecting the temperature wire (connected to the ground side of the batteries) and reconnecting it. [Mine was loose which may have contributed to the problem.] I have also heard of people unplugging the wire at the inverter also. I would suggest you call the Dimension builder at Sensata Technologies and ask for help. I have also heard of the wire from the inverter becoming badly frayed or corroded and needing to have a new wire connector installed. Good luck and let us know what your find out.

MrTransistor · 08-28-2010, 11:58 PM

Hi KWC,

Do people actually read these posts before they comment? You state very clearly that ‘The batteries are not hot.’ and imply that you are stationary. At that point, I would check; the sender unit attachment to the battery, the connector at the inverter for the battery temperature input, and last but not least, the wire continuity between the two. Odds are good that one of these will fix your problem. If not, then the problem will be a defective temperature sender or the inverter itself. Lets hope not, keep us posted on your progress.

tomsm · 08-29-2010, 08:19 AM

KWC - My original Dimensions inverter was zapped in a lightning strike about a year ago. I never saw that high battery temp message on the old unit. However, since I now have a newer model (probably the same as yours), I now see that message from time to time. So far it's only been on drive days with hot afternoon temps. Waiting a while or opening the battery bay has always cleared it. Sounds like yours is going overboard on this preventative behavior.

Does your float voltage also vary according to ambient temp? I've noticed that mine does. By the manual, it's supposed to float at 13.2. But, on a warm afternoon it floats at 12.7 - 12.9. The next morning it wil be floating at 13.1 - 13.2. My original unit always floated at 13.2 regardless of temps. Apparently, they've added some new logic. I can't decide if it's good or bad... I check water levels frequently and haven't needed to add water in 8 months. We don't dry camp often and I have power available at my storage location, so it's almost always plugged in. I think it's great that it's not boiling off water, but I wonder if the batteries are being kept fully charged.

I'll be interested to see what you find out since I may be headed in that direction...

KWC · 08-29-2010, 01:13 PM

Water is a great place to start. I did check the water in each cell. I added a little water to a few but they where all at safe levels. All four Batteries are new maybe 10 Months.

The charger seems to be tracking the outdoor air temp. Everything reset last night when things cooled down but around 2 pm and 90 deg today the Battery High Temp turned off the charger agian. This indicates to me the temp sender / sensor seems to be working. I do not think it can be calibrated I believe it works or does not.

i disconected cleaned and tightened the temp sensor lug from the battery neg termanal, and all looks fine at the conection to the inverter.

I may invest in a new remote temp. compensator cable, but I feel like it is not the problem. I think I may contact Dimensions

Not sure exactly how it works but I did notice my inverter was in float mode @ 12.4 Volts.

dirko · 08-29-2010, 04:18 PM

Hi Ho: Isn't technology wonderful? If the terminal voltage on the batteries is only 12.4 volts they won't be fully charged. Our old-fashioned converter simply maintains the voltage at 13.6 volts and we don't have any problems. I only add water every few months depending on outside temperature. It can actually go the entire winter without any being added.

What is the temperature sensor? a thermistor, varistor, diode or band-gap in an IC? You could probably change the sensor if you knew exactly what the circuit is. Does Dimensions supply a schematic of the circuit. You call it an inverter, so I assume that it also functions as a converter for the battery charger...

If you have a schematic I'm sure you would find a solution here.

Dirk

Harry B · 08-29-2010, 04:30 PM

I had the same problem a couple of weeks ago. High Battery Temp. with ambient temp about 95. Batteries were warm but not more so than I have seen at other times. The inverter/converter reset itself after a while. It seems to be a problem with the inverter/converter. I had a spare remote temp sensor and installed it with a re-occurrence of the problem a couple of days later. Also had a lower float voltage at 12.7v (normally at least 13.0v).
Normal reading on the Dimensions remote temperature sensor is 21K ohm at 75 degrees with resistance getting lower/less as the sensor gets warmer.
This is my 3rd Dimensions and I finally decided that that was enough and replaced it with a Magnum.

That took care of the problem

MrTransistor · 08-29-2010, 10:12 PM

Hi KWC,

A 12.4 float is not correct, time to contact Dimensions. In the mean time, those batteries need to be charged. Try removing as much load as possible and connect a portable charger to bring them back up.

Hi Dirk,

Real schematics? These days? All you could do is take readings on a known good one at 0° and 212° and try to match it. Getting the right housing could be a problem. Inverter/Chargers in RVs do function as Inverter/Charger/Converters. The cheap ones are modified sine wave and about double the price will get you a true sine wave unit.

Hi Harry,

Yep, 12.7 is wrong also. I don’t know Magnum but there seem to be problems with the Dimensions.

two-niner · 09-02-2010, 04:06 PM

KWC: I had the same problem driving through Phoenix (113 degrees) on I-10. The generator was on, basement a/c on and dash air on. Battery charger OFF.
Without lengthing the story, when we arrived in Tucson I turned the handle at the bathroom sink and steam came out. When the water started out I ran my hand under it and it was scalding hot!! (The water heater was off).
In a way I was glad to read your post as it leads me to believe that somehow the design of the Tour(08) is faulty as far as shedding heat in the rear of the coach.
It has happened once again in CA coming to NV. Battery charger off, scalding water.
However once cooled off at home, on shore power, all systems went back to normal even with 105 degree ambiant air (MH under shade).
Please keep us posted with your situation.

Kerry

KWC · 09-03-2010, 06:19 AM

Update to all,

I contacted Sensata 651-653-7000. They are the manufacturer of the Dimension Inverter, very easy people to talk to. I did not have the Service Manager on the phone but they did give me a few things to get started with.

They informed me the operating temp Resistance on the temp sensor should be around 16K to 20K. The resistance lowers as the temp goes up. I plan to check the resistance and check the resistance change with some ice water. I also ordered a new sensor it was relitivly inexpensive and I plan to install it regardless of my testing results. I can keep the old for a spare if it proves fuctional.

I feel and others I talk to feel the Charger in float mode sitting at 12.4V is not good. The Dimension Manufaturer asked me to Verify the remote panel reading with a good meter and get back to them.

Thanks for the comment and suggestions. I will keep you updated with the progress.

tomsm · 09-03-2010, 04:05 PM

KWC - thanks for the update. I'm betting the new sensor will make a big difference - look forward to reading your results...

OneRVer · 09-03-2010, 04:41 PM

Just one more question. While you are parked and the alarm comes on, or what ever it does, is the battery compartment in the sun? Has this ever happen when the compartment is in the shade?

rowesort · 09-07-2010, 09:35 AM

Quote:

Originally Posted by KWC

Water is a great place to start. I did check the water in each cell. I added a little water to a few but they where all at safe levels. All four Batteries are new maybe 10 Months.

The charger seems to be tracking the outdoor air temp. Everything reset last night when things cooled down but around 2 pm and 90 deg today the Battery High Temp turned off the charger agian. This indicates to me the temp sender / sensor seems to be working. I do not think it can be calibrated I believe it works or does not.

i disconected cleaned and tightened the temp sensor lug from the battery neg termanal, and all looks fine at the conection to the inverter.

I may invest in a new remote temp. compensator cable, but I feel like it is not the problem. I think I may contact Dimensions

Not sure exactly how it works but I did notice my inverter was in float mode @ 12.4 Volts.

This may just be a shot in the Dark;
but on my coach I have an Xantrex Inverter and solar panels the solar panels have a temperature senser to adjust the voltage based on the outside ambient tempterature. The shape of the the temp senser would implie that you connect it to a battery post but in fact you do not, batteries warm up when charging, the temperature sensor was used to adjust the voltage based on the outside temperature. The batteries when heating would give off an incorrect reading. I would check your charging rate with a reliable (accurate) multi meter. If your charging over 15 volts your batteries are going to heat up. Most invertor chargers have a an equalizer cycle which charge to 15.5 volts. and can be set to come on at regular intervals. I set mine to manual.