Low DC volts as I turn the lights on

mikeandconnie

Well-known member
This morning when I turned the lights on I got a DC low volt warning alarm. I removed the battery, checked the water and cleaned the connections and still had the same problem. I checked the voltage and with No lights on I'm reading 14 volts, as I cut the lights on the voltage drops as low as 7 volts. When I turn the lights off the voltage goes back up to 14 VDC. I suspect the battery is bad but it's only 11 months old so I'm not sure.

Thanks for any suggestions or input.
Mike
 

FiremanBill

Well-known member
yep, sounds like a dead cell in the battery. You can take it an auto zone or Advance auto, or similar type store, and have it load tested. They will likely confirm your suspicion that the battery is bad.
 

danemayer

Well-known member
With the battery disconnected, if you're plugged into shore power, the Converter should supply 12V power to the fuse box and everything should operate normally. If the lights/low voltage warning still show a problem with battery disconnected, it's not the battery. Here's a link to a 12V guide that might be helpful.
 

hoefler

Well-known member
I would check the convertor output. If your plugged in, the lights should never dim, as the convertor picks up the load. The battery acts as a capacitor when you are plugged into shore power.
 

TeJay

Well-known member
Understanding the three components of electricity really helps. RESISTANCE: This is what opposes the flow of current. Copper wire has low resistance to current flow. The filament in a light bulb (nichrome) is a good example. Edison used thread covered with carbon powder to make the first light bulb. The resistance of the filament glows as it resists the current flow. CURRENT: This is what does the real electrical work. A small light bulb may require 1-AMP of current while your car headlight may require 15-amps. The more work an electrical device does usually requires more current. VOLTAGE: This is the pressure behind the current. The voltage requirement in a 12-volt system does not change for it to do it's job. Soooo when you measured the voltage yes it read 14 volts but the lights dimmed because there was no sufficient current available to do the work. The pressure was available but not enough current. By measuring the voltage at the battery (B+) while plugged into shore power will tell you if the converter is capable of re-charging the B+. The converter voltage has to be above the B+ voltage to force electrons back into the B+. That voltage is around 13.6-14.0. Never condemn a B+ or a B+ cell without doing more B+ testing. As suggested take the B+ to a reliable testing place and have it load tested. To accurately do that the B+ should be charged with a good portable charger before you take it in. If it's not charged for at least 6-12 hours it can't be accurately tested. If it is charged and then fails a load test then yes it has an internal problem and should be replaced.
TeJay
 

mikeandconnie

Well-known member
Yes I'm plugged in and getting 13.6 volts of changing from the converter and you would think that's would be working correctly with that voltage, but I have no way of checking amps. I'm wasn't sure if the converter had enough amps to run every thing in the rig with out the battery. The heater blower and all the lights. It's worst this morning so I may try to find a bigger battery anyway. My last rig had dual 6 volts battery's, this one has just a small 12 volt... I'm doing a load test with the lights and it's failing. It may be the converter by using the chart above..
Thanks,
Mike
 

jbeletti

Well-known member
Mike,

If you do end up needing to or wanting to replace the battery, dual 6 volt batteries are usually a good option. I did that in my first Landmark. I have read on this forum that Sam's Club has a decent 6 volt battery at a reasonable price. Or you can source some Trojan T-105 model batteries. Two of those will fit the Landmark battery tray (my experience).

Jim
 
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brianharrison

Well-known member
13.6V tells me the converter is working - I assume this is measured across the battery terminals?

I beleive most newer Landmarks have the 80amp Progressive Dynamics 9200 series (ie 9280 link) intelligent chargers. More than enough amperage to run everything in the coach without batteries - except maybe the slide motors (the extra capacity is drawn from the battery).

The charge wizard pendant that goes along with the 9200 series is a good tool to use to monitor the intelligent charger modes (bulk, absorption, and float). It also allows manual step-through to change modes. Here is the link to the charge wizard pendant for 9200.

Something else is not right - I would troubleshoot before buying another battery (or 2-6Vs). You may be in the same situation except you'll have two new batteries with low capacity?

Brian
 

mikeandconnie

Well-known member
I'm taking the reading from the level up meter connected to the system. I confirmed it's correct with a meter. I see why it's worst today, I forgot to turn the battery back on yesterday. With nothing running and the battery disconnected I have 13.6 volts. With the furnace on it drops to 10.5 and keeps dropping as I turn lights on.. I would think 80 amps should run the heater fan without that big of of a drop...
 

brianharrison

Well-known member
I am not familiar with where the level up meter is tied into the 12V system and I have not used it to measure system voltage.

The converter is doing something at 13.6V - if it was not you would only see voltage of 12.8 or less in the system (relaxed/full battery voltage) - can you confirm the 13.6V is across the battery terminal (to ensure it is seeing this voltage). As well can you measure voltage at the DC panel at 13.6 as well?. A final check would be 13.6V at the buss bar.

You may want to hook up your idling truck and plug in the 7pin and repeat tests. Regulated voltage should be 13-14V as well out of the 7 pin from the truck (taking into consideration voltage loss in the factory wiring harnesses).

Brian
 

mikeandconnie

Well-known member
Well, my bad. The lights are working much better with the battery on. So the converter is working but I'm getting a voltage drop without the battery.
 

mikeandconnie

Well-known member
With the battery on the volts are 13.2 with all the lights on, so it's working normal now and I'm not getting the low volt warning like I had yesterday. The battery connection where very corroded and I was thinking this was the problem. Seem to help. However, I sure with 80 amp from the converter I should not get the voltage drop like I'm getting without the battery.
 

danemayer

Well-known member
You may have something sucking up the power from the converter. I'd expect it to power everything when the battery is off. Lights may dim/brighten occasionally as it changes modes. On another thread a day or two ago, someone else found a loose wire on the back of their fuse panel causing problems.

What device is giving you a low-voltage warning?
 

mikeandconnie

Well-known member
The Norcold Fridge has a Low DC power warning light and beeper. The furnace alone will give me a low volt warning and cutting on two lights switches will do the same. I suspect this is why my fridge is been acting weird and I had a tech coming this afternoon. I ask him to wait but he agreed the converter should run every thing in the rig without a big drop like I'm getting. I will call progression and see what they say. I hate paying the service charge when I can do the work.
 
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mikeandconnie

Well-known member
Using the T/S manual my converter is OK. I may have a bad cell or it was the corroded connection. The volts are 14.4 right now, so the battery is low. I will load check it this afternoon. My fridge didn't freeze last night with the heater running causing low voltage, so I'm hoping it will start working also.

The forum is great for problem solving
Thanks everyone,
Mike
 

TeJay

Well-known member
What you have been told is spot on. The voltage at the B+ is your best indication that the converter is working. How it works and what it's charge rate is dependent on the circuit design and I'm sure it's different but basically the same for different converters. If you've got 13.6 volts at the B+ and you still can't run everything as the converter is designed to do then I would make sure that the B+ is load tested at a good shop. When a B+ is load tested here is how it is done. If the B+ has a CCA rating of say 400Amps they will load it down with 1/2 the CCA (cold cranking amps) or 200amps. Remember that amps is current. So they will load it down with 200-amps and hold it for 15 seconds. At the end of 15 seconds the voltage (pressure) should not drop below 9.6 volts. If it does then it tells them that the battery is in a state of discharge. They will then charge the battery with a good charger until it says that it is fully charged and re-test the B+. If it fails again then the B+ needs replaced. That's why I mentioned charging the battery before you take it to have it tested. You can avoid them telling you that it failed the test and it needs charged for 12-24 hours and then they ca run the test again.

Any good 12-volt wet cell storage battery will run your camper stuff longer than you are telling us that the current battery is doing. Your B+ is not to small unless you have a 12-V motor cycle B+. The physical size of a B+ is directly related to the amount of amperage or current that it can deliver. Six volt batteries have been mentioned. Two 6-V B+'s connected in series, which gives you 12-V's is twice as good as 1 12-V B+ and still better than 2-12-V B+'s connected in parallel. The Trojan B+'s are the way to go if you have the room. They are deep cycle and very rugged.
TeJay
 

mikeandconnie

Well-known member
I spoke with the Heartland and the local service center here, they both agree with you all that the converter should run all the systems when connected to shore power. It could be the converter or a connection problem. They also said the refrigerator will not work very well with fluctuating DC Power. I going to take this one in for warranty.

Thanks for all the Help
Mike
 
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