CO/propane alarm issues

Sagecoachdriver · 11-10-2017, 11:36 PM

While coming back from the Grand Canyon and spending the night at a Laughlin Casino (no hookups), my CO2/propane alarm went off this morning when I turned up the furnace. Woke the DW at scared the dog. I'm sure it was low voltage as there was only 12.0 volts on the battery monitor. We had the fans on yesterday afternoon and evening along with the TV, Sat receiver going off the inverter. I tried to silence it by pushing the test/mute button with no luck. I turned off the furnace and it stopped immediately afterwards. The sun was low and solar panels showed next to nothing in output.
Has anyone had the same experience and has anyone changed out the unit for one that doesn't send out a low voltage alarm?

n-e-d · 11-11-2017, 06:13 AM

I had it happen while hooked up at CG in New York. Pulled the fuse to silence it, thought I had a bad converter. Long story short found a bad crimp terminal on battery while installing Trimetric monitor, as far as replacing it(co/propane) kind of glad to have had an excuse to get the Trimetric and a new converter

**Herk7769** · 11-11-2017, 06:39 AM

Under high load the voltage will be lower on a partially discharged battery.

The battery alarm would have sounded on a new monitor.

Solution for winter camping is "more battery" and never go a day without charging it up with your generator.

Sagecoachdriver · 11-11-2017, 10:11 AM

Herk, we have 2 group 27 batteries and 200 watts of solar. Left Grand Canyon Trailer Village where we had full hook ups so batteries were full. Again running the maxi fan and Fantastic fan during the afternoon to keep the dog cool and the TV at nigh put a good drain on the system. Again when I checked the battery monitor it said 12.0 volts and a total draw of 55 amps. I would never try to bypass the system but maybe there is one out there what won't set off a low voltage alarm.

**Herk7769** · 11-11-2017, 06:27 PM

Quote:

Originally Posted by Sagecoachdriver

Herk, we have 2 group 27 batteries and 200 watts of solar. Left Grand Canyon Trailer Village where we had full hook ups so batteries were full. Again running the maxi fan and Fantastic fan during the afternoon to keep the dog cool and the TV at nigh put a good drain on the system. Again when I checked the battery monitor it said 12.0 volts and a total draw of 55 amps. I would never try to bypass the system but maybe there is one out there what won't set off a low voltage alarm.

55 amps is a pretty good draw!

Lead acid batteries have a property called the Peukert Effect. It is most noticeable with deep discharge batteries at high amp draws.

Battery plates receive and discharge electrons only from the plate surface actually in contact with the electrolyte.

Starting batteries have thin waffled plates so that they can give up LOTS of electrons quickly, but have little "capacity" beyond what is needed to crank a cold engine. They are rated in CCA or total available cold cranking amps for 30 SECONDS without dropping the voltage below 1.2 volts per cell (7.2 volts!).

Deep discharge plates are thick so they contain lots of space for electrons to live until they are needed and have flat faces to fit the most lead into the plate. This results in the most available capacity, BUT reduces the surface from which electrons can be pulled. Trying to pull more electrons rapidly from plates of this design rapidly decreases the capacity because the ability to push (or pull) the electrons (voltage) off the plate is decreased.

The more you try to pull, the quicker the voltage drops, and as a result the lower the effective capacity of the battery.

Lets take a notional 100 amp hour rated battery. 100AH is defined as the ability to deliver 5 amps (yes 5 amps) for 20 hours until the battery is dead (voltage less than 10.5 volts).

Trying to pull more than 5 amps from the battery will reduce the effective capacity from 100AH. This graph displays that reduction in visual form. The graph does not even go to 55 amps (for ONE battery)!

Two batteries are needed to share the 55 amp load (if properly wired) evenly. Each battery in this case will "see" only 1/2 of the load (or 27.5 amps per battery).

Enter the graph at 27.5 amps and you will see that each of your 100 amp batteries will only be capable of delivering 55AH each (a reduction to only 55% of a fully charged brand new battery). This should yield an "observed voltage under load" of 12.3 volts.

So at 27.5 amps draw, each battery in your battery bank will give up the ghost in about 2 hours if that demand is continuous (27.5 into 55AH). The solar will help while the sun is out and your draw should not be continous (that's why your batteries are not dead over night!)

Additionally, when the draw is removed (or lowered), the voltage will recover as electrons are able to move from the center of the lead to the surface.

As the available remaining capacity continues to be used up, you need to recalculate the "remaining capacity" to see where the actual capacity to deliver power now resides. "12.0 volts" is actually about 50% capacity remaining; so your 100AH battery contains only 50AH left. Trying to pull 27.5 AH from a 50AH battery will reduce that batteries ability to deliver voltage by a percentage based on the batteries construction (actual Peukert number). To get an idea of how that will impact your system, you can use the graphed 100AH chart as a percentage.

At 50AH capacity, that 27.5 AH per battery will reduce the capacity again by that same 55% (or 50AH available capacity times 0.55 = 27.5% of initial battery capacity) Etc. This should yield an observed voltage under load of about 11.7 volts.

It will just get worse as the night (and heater use) wears on until the batteries unable to generate enough voltage to keep the inverter online (if used) or the Propane monitor from alarming (my detector alarms at 8.5 volts DC).

I hope that helps to explain why your awesome system is not holding up while Boondocking. My dual battery system is unable to make coffee using an electric coffee maker (1200 watts) for example. That draw on the batteries is 100 amps! or 50 amps per battery. My batteries alarm before the water even gets warm.

I attached the mathematical proofs for the purists. The graph works for me as it is easier for me to "guestimate" battery life based on demand rather than run the math every time the battery voltage drops.

My Trimetric does it all for me in any case! No "head work" required.

**Herk7769** · 11-11-2017, 06:45 PM

I forgot to mention "Hybrids" which have plate designs that attempt to provide "good" starting performance as well as "good" storage performance.

Called "Marine" or "Dual Purpose" or "RV" batteries, they incorporate plates thinner than true deep cycle batteries with a face design that allows more surface area for electron generation.

There are two ways to look at them.
One, they suck at either; or two, they are "OK" at both!

IMO, if you need both; buy a starting battery to start the boat or motrorhome, and storage batteries to use while boondocking.

Sagecoachdriver · 11-11-2017, 08:32 PM

Noticed when I got home last night from driving from Laughlin NV to LA, 5 hours that there was still 18 amps down on the battery monitor. Checked this morning when I went to refill the gas and the darn Battery Isolation Manager wasn't allowing the alternator to charge the house batteries. I think part of my problem is that the solar is giving a charge directly to the house batteries and not allowing the alternator to house battery's solenoid to kick in. When I got back home I checked and it still wasn't charging the batteries which were still down 18 amps. When I cut off the solar panels and restarted the engine, I heard the click and could see the 14v+ charging on the battery monitor. Reading Precision Circuits website on this BIM, it only will allow the alternator to charge the house batteries for 1 hour while driving so as not to overcharge the house batteries. To continue having the alternator charge them I would have to put on a good draw bringing down the voltage to 12.5 or shut down the engine for 10 to 15 minutes for the BIM to reset. Solar only confuses things. So I guess the best way to handle this is to turn off solar with the disconnect when starting our drive and after 1 hour turn solar back on. Only 2 100 watt panels and I don't believe they are working properly as the never seem to get above 3.5 amps each and have noticed snail trails on them. Going to Renogy Solar on Monday for them to check output while under warranty. Perhaps I'll get another one or two.

**Herk7769** · 11-11-2017, 09:58 PM

Quote:

Originally Posted by Sagecoachdriver

Noticed when I got home last night from driving from Laughlin NV to LA, 5 hours that there was still 18 amps down on the battery monitor. Checked this morning when I went to refill the gas and the darn Battery Isolation Manager wasn't allowing the alternator to charge the house batteries. I think part of my problem is that the solar is giving a charge directly to the house batteries and not allowing the alternator to house battery's solenoid to kick in. When I got back home I checked and it still wasn't charging the batteries which were still down 18 amps. When I cut off the solar panels and restarted the engine, I heard the click and could see the 14v+ charging on the battery monitor. Reading Precision Circuits website on this BIM, it only will allow the alternator to charge the house batteries for 1 hour while driving so as not to overcharge the house batteries. To continue having the alternator charge them I would have to put on a good draw bringing down the voltage to 12.5 or shut down the engine for 10 to 15 minutes for the BIM to reset. Solar only confuses things. So I guess the best way to handle this is to turn off solar with the disconnect when starting our drive and after 1 hour turn solar back on. Only 2 100 watt panels and I don't believe they are working properly as the never seem to get above 3.5 amps each and have noticed snail trails on them. Going to Renogy Solar on Monday for them to check output while under warranty. Perhaps I'll get another one or two.

I agree, something is not right. Starting out with only a partially charged battery will only make a tough boondock tougher on the batteries. Discharging them below 50% capacity (11.9 volts) can cause permanent loss of AH capacity.

This needs to be checked out. It kinda makes sense that if the solar controller is putting out a higher voltage than the average voltage of the house and starting batteries, your alternator will not charge the house battery or starting battery allowing the enemic solar panel charge rate to try and charge both through the camper's battery control center.

Remember that the highest voltage source will be the charge source. The diodes in the alternator's voltage regulator will prevent back feeding the alternator. The alternator might be seeing the 13 plus volts on the battery buss (from the solar controller) as the batteries are full and not need charging.

Here is some good info on why alternators make poor charging sources for deep cycle batteries.

Sagecoachdriver · 11-12-2017, 10:37 AM

Thanks Herk, the DW reminded me that the alarm went off at like 5am on a cold night earlier in the year. Again when the furnace came on. I opened the windows thinking it was Carbon monoxide or a propane leak and turned on the fans. Of course it wouldn't shut off because the fans were drawing down the voltage. Really scares our dog taking 20-30 minutes for her to stop shaking. Just worried we may be out with the dog left inside with the fans going and have the alarm go off. Has to be a solution here. Going to call the manufacturer tomorrow. There are many battery powered monitors but none for propane only carbon monoxide.
Just ran out and checked to see if the battery cut-off kills all power to the sensor alarm and it does. That's one way to stop it quick!

**Herk7769** · 11-12-2017, 11:36 AM

Quote:

Originally Posted by Sagecoachdriver

Thanks Herk, the DW reminded me that the alarm went off at like 5am on a cold night earlier in the year. Again when the furnace came on. I opened the windows thinking it was Carbon monoxide or a propane leak and turned on the fans. Of course it wouldn't shut off because the fans were drawing down the voltage. Really scares our dog taking 20-30 minutes for her to stop shaking. Just worried we may be out with the dog left inside with the fans going and have the alarm go off. Has to be a solution here. Going to call the manufacturer tomorrow. There are many battery powered monitors but none for propane only carbon monoxide.
Just ran out and checked to see if the battery cut-off kills all power to the sensor alarm and it does. That's one way to stop it quick!

I would try to find the reason your batteries may not be charging properly and where the heavy draw is coming from. 55 amps DC is huge.

Sagecoachdriver · 11-12-2017, 12:16 PM

Quote:

Originally Posted by Herk7769

I would try to find the reason your batteries may not be charging properly and where the heavy draw is coming from. 55 amps DC is huge.

The alternator did not charged the batteries on the 3 1/2 hour drive from the Grand Canyon to Laughlin NV. It was overcast, so solar didn't charge much. Ran Maxi and Fantastic fan for 4 hours and then used the one fan, TV and Dish receiver that was on inverter. Draw in evening was 10.2 amp, so 55amps drawn seems normal considering. Better solar output would have helped.

newRVer · 11-13-2017, 08:21 AM

Is there some confusion about 55A draw and 55 amp hrs drawn? There is a big difference between them.

PS. I should be getting my 200 watts of solar online next weekend and will be doing some testing and monitoring over the winter. By next spring I probably will have two new batteries and a battery monitoring system as well. Hopefully by then I will have figured out a strategy on the best way to use the solar. Given what Sage said previously, I wonder if it's best to turn off the panels while driving and let the alternator take care of the charging?

**Herk7769** · 11-13-2017, 09:16 AM

I don't think there is confusion between the OP and I.

Using an inverter to power some AC items, an instantaneous 55 amps DC is not out of the question.

Slide out motors 25 amps each
The furnace draws 12 amps DC when running
Variable speed ceiling fan 4-5 amps each
65 Watt AC TV draws about 5.5 amps from the battery
Each 921 light bulb draws 1.2 amps so each 2 bulb fixture on draws 2.4 amps; say 3 fixtures on draws 7.2 amps
Porch light on outside another 1.2 amps
water pump 4 amps
Charger for iPad or Kindle about 2.5 amps
Laptop transformer (mine) 120 watts or 10 amps DC
2 "newer" Phone chargers (60 watts AC) about 5 amp DC
Radio on to power surround sound for TV another 5 amps DC

It all adds up quickly and if you have a "real" computer it gets crazy fast as a 500 watt computer power supply will draw 40 amps DC all by itself (from an inverter) at full power.

The effect on a battery bank for high draw items can not be overstated, especially as the battery voltage decays over time as capacity is used up.

Since watts are the product of voltage and amperage, if the power requirement is fixed (as in motors) and the voltage goes down as the AH available decreases due to high amperage demand, the current needed actually increases. The cascade will rapidly reduce voltage even more.

This effect is easy to demonstrate with a volt meter.

Disconnect from the solar panels and shore power; connect the volt meter to the battery; then try to open two slides at once. You will see the available voltage (and thus the remaining battery capacity at that high current draw), decrease. Once the slide out stops moving, you will see the voltage (and thus capacity) recover to a voltage closer to its no load state.

Steady state high current draws on a mostly discharged battery can reduce the available voltage to well below the cut off voltage for inverters and even turn on the CO/Propane alarm.

Sagecoachdriver · 11-13-2017, 07:58 PM

NewRVer, the alternator only charges for the first hour of driving and won't charge again unless the house battery voltage drops down to 12.5v or you stop, turn off the engine for 10 minutes. So best to keep the solar panels connected at least after the first hour or you will arrive at you destination with less than full batteries. Check out Precision Circuits document.http://www.precisioncircuitsinc.com/...anual-RevA.pdf

Today, I drove over to Renogy with my panels and they tested them as best they could. Seems their tester is not working and they did a limited test. Voltage was down on one panel. They gave me 2 new panels to replace mine basically because of the snail trails. I installed them late this afternoon and it was tedious trying to align the mounts and tighten the bolts. Took about an hour. By the time I finished, the sun was down. Hopefully, the sun will be out tomorrow. I never got the chance to call the CO/propane alarm manufacturer but will do it first thing tomorrow and will post their reply on the low voltage alarm.

n-e-d · 11-14-2017, 05:52 AM

Bottom line here seems to me that the CO/Propane detector preformed well in showing a problem with Sage's usage/power supply setup as it did in my rig with a bad crimp coupling. Kudos to Herk on those posts very informative

newRVer · 11-14-2017, 08:31 AM

Quote:

Originally Posted by Sagecoachdriver

NewRVer, the alternator only charges for the first hour of driving and won't charge again unless the house battery voltage drops down to 12.5v or you stop, turn off the engine for 10 minutes. So best to keep the solar panels connected at least after the first hour or you will arrive at you destination with less than full batteries. Check out Precision Circuits document.http://www.precisioncircuitsinc.com/...anual-RevA.pdf

Today, I drove over to Renogy with my panels and they tested them as best they could. Seems their tester is not working and they did a limited test. Voltage was down on one panel. They gave me 2 new panels to replace mine basically because of the snail trails. I installed them late this afternoon and it was tedious trying to align the mounts and tighten the bolts. Took about an hour. By the time I finished, the sun was down. Hopefully, the sun will be out tomorrow. I never got the chance to call the CO/propane alarm manufacturer but will do it first thing tomorrow and will post their reply on the low voltage alarm.

Thanks Sage. Let us know how it works out. We typically drive no more than 2hrs at a stretch and then stop for 15 mins or so. I will have to follow my house battery voltage next season to see if it does follow the along with the doc from Precision.

Also, it seems I did not comprehend that the 55A you were previously speaking about was out of your inverter, which would make sense.

Sagecoachdriver · 11-14-2017, 11:27 AM

OK, I called MTI Industries the manufacturer of the Safe-T-Alert CO/propane alarm this morning. They said the low voltage alarm is triggered at 10.5 volts or below. I indicated to them that it was triggered at somewhere between 11.8 and 12.0 volts as shown on my battery monitor. They said it is defective and out of the 1 year warranty and half way thru it's life of 5 years. Guess I'll have to buy a new one.

Sunny day today, going to see what the output is with the replaced solar panels and compare it with my Renogy suitcase. I didn't buy another 100 watt panel while I was at their plant as Black Friday is coming up quick and I can get a better price then either from them or on Amazon.

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