House Battery draining, Why? 2018 FR3 32DS

[str8edg]

I’ve been having an issue with the house batteries staying charged. I always shut off the disconnect at the step on my way out. I have been exercising the generator every 3-4 weeks and every time when I open the door the steps don’t even come (this has been occurring the past 2 months). So, I have to start the chassis and after a few minutes I open the entry door the steps drop down, I can turn on the lights, and start the generator.... any ideas? Checked the battery fluids and they are fine, not sure what the issue can be???

I have to cool the fridge down before a trip and I’m going to have trouble if those batteries don’t wanna work.

[houstonstroker]

Originally Posted by str8edg

I’ve been having an issue with the house batteries staying charged. I always shut off the disconnect at the step on my way out. I have been exercising the generator every 3-4 weeks and every time when I open the door the steps don’t even come (this has been occurring the past 2 months). So, I have to start the chassis and after a few minutes I open the entry door the steps drop down, I can turn on the lights, and start the generator.... any ideas? Checked the battery fluids and they are fine, not sure what the issue can be???

I have to cool the fridge down before a trip and I’m going to have trouble if those batteries don’t wanna work.

How long are you leaving the rig before returning? Batteries will self discharge. Also there are numerous parasitic loads. The only way to kill the parasitic loads is to pull the battery cable off.

[CHICKDOE]

i had this problem with our trailer. the batteries would discharge enough in a couple of weeks to the point they would not start the generator. i always turned off the factory installed battery disconnect switch. it turns out the disconnect switch did not remove all loads from the batteries. i think i identified 4 or 5 devices that were still connected and drawing power from the batteries. there devices included propane detector co detector, inverter, stereo, and slide out controller. any device that stores things in memory or uses a receiver to listen to a remote transmitter is probably still connected.

i put my own disconnect switch on the battery cable that removes all loads. since i did that the batteries barely lose anything over a couple of months. i exercise the generator each month and a byproduct of this is that the batteries get a boost every month.

[TitanMike]

The average "self discharge rate" of a lead acid battery is about 5% per month. Using simple math this means that a good battery will loose 60% of it's capacity each year.

If the batteries are subjected to other parasitic loads like LPG detector, radio (to maintain preset stations and time setting), this rate can increase measurably.


No factor in the REAL state of charge of the batteries before shutting them off and their age. To fully charge a battery it can take up to 24 hours on a charger, depending on charger and battery age/condition. A couple hours "exercising the generator" will not fully charge a Lead Acid Battery and may not even keep up with the self discharge rate. Unless you are using a monitor like A Victron or Xantrex, you really won't know if your batteries are fully charged when the generator is shut down. The LED "Christmas Tree" used by many, if not most, to measure battery SOC is essentially worthless in determining SOC on batteries. They lie when they say the battery is charged to 100% and are probably only accurate when they tell you the battery is dead.

A $10 Hydrometer is the best tool if one doesn't want to invest in a good Battery monitor.

[rlh1957]

Turn off the main battery disconnect, go inside and push all your indicator check buttons and see if any light up, does your clock on the radio still run, microwave clock, check the smoke detector and see if it works, look at the CO/LP detector and see if it works. Did you or anyone else add any device directly to the battery?

Get an Amp meter that measures AC & DC amperage. Some auto stores have these to test or rent. Use the Amp meter per instructions for DC current and see if there is any draw indicated. Parasitic draw from one little tiny LED can draw a battery down over weeks, then the CO/LP detectors on many units operate as long as there is a battery with a charge, regardless of battery disconnect switch position.

You can take the battery out and any automotive store can tell you what the charge state is and if the AMP discharge rating listed is actually what the battery can do now. Battery self discharge just sitting disconnected depends on what shape the batteries are. After 3 years batteries can start to degrade, after 5 years always budget for batteries that could go out... some folks get good service even at 7 years. So many factors make it difficult to predict.

[TitanMike]

Originally Posted by rlh1957

You can take the battery out and any automotive store can tell you what the charge state is and if the AMP discharge rating listed is actually what the battery can do now.

You must go to different Auto Parts stores than we have around here. Most have a hard time finding the battery tester and if they do they don't know how to use it.

Only way you can really test a battery's remaining capacity after fully recharging is to put a known load on it and record the time it takes for it to reach fully discharged. These "push button testers" are at their very best only capable of telling you whether or not the battery will start a car/truck. Not remaining amp hours.

For deep cycle batteries it's best to take it to the pro's that deal in real deep cycle batteries (Like and Interstate Service Center among others), not a A/P store.

[CHICKDOE]

mr titanmike,

i do not disagree with a word you posted.

before i added a total disconnect the batteries would discharge in a couple of weeks. once i added the total disconnect they can go months with only the most minimal discharge.

the only method i have of checking battery status is to measure voltage, at rest. every time i go over to the trailer in storage i check the voltage on the built in voltage meter (lippert level up control panel). the trailer has been sitting for a week and i was over this morning and the voltage was reported as 12.9 volts. perhaps i ought to take my fluke meter over and use it to get a comparison reading and see if the lippert display is off a bit.

i have maintenance free sealed lead acid batteries with no caps so a hydrometer is out.

i have not put a battery monitor on as we do not do major boondocking. and there seems to be a conundrum with a battery monitor, at least as i understand it. how you hook it up has implications. if you wire the shunt and monitor between the battery and the battery disconnect you now have a new parasitic load. not a big one, but it is there. so you can use the battery monitor to watch it drain the batteries. if you wire it after the battery disconnect it will loose power when you disconnect the batteries and you will be unable to tell you their status so you can determine when to recharge them. once you reconnect the batteries you will repower the monitor and it will in effect reboot. it will not know the status of the batteries and my understanding is it has to monitor the batteries for some time in order to determine their status. i think it waits until the charging amperage tapers off to a small amount in order to determine that the SOC is 100%. prior to this it does not know. you will not be able to know the battery SOC when you reconnect them. about all that you can know is voltage. anyway, this is as i understand it and there is certainly the possibility that i have this wrong.

[camaraderie]

I believe the op has murdered his batteries due to inadequate charging and leaving them hooked up for parasitic loads and 10-20% monthly self discharge in moderate to warm climates respectively Exercising the Genny for anything less than 6 hours will leave the battery stored partially discharged and a loss of capacity is the result.

[TitanMike]

Originally Posted by CHICKDOE

how you hook it up has implications. if you wire the shunt and monitor between the battery and the battery disconnect you now have a new parasitic load. not a big one, but it is there. .

According to Victron the BMV 712 monitor draws <1 mA when the monitor backlight is off.

If a 100 Ah battery was fully charged and there was NO internal discharge in the battery, the Victron monitor would drain the battery in approximately 11 years.

No need to worry about the meter drawing power. It's the other items that make the difference. Right now my TT is sitting with the battery switch ON and the monitor is reading a steady .2 amp "parasitic" draw. This is from the Stereo (memory maintenance), AC/Furnace Thermostat, LPG detector and maybe some going to the tv amp even though the display is shut off (I have a Sensar Pro which is different than the OE amp that has an on/off switch).

I have my TT at home on a pad and plugged into a 30 amp pedestal. When I leave my Refrigerator on the "draw" jumps to .7 amp.

Even with the .2 Amp draw my batteries only get low enough to turn on my converter's charging section (I added the on/off module from PD) every 20 days or so.

Since I usually run off to camp for a week every couple weeks the "Auto" function rarely is needed, I flip the "Charge" switch on (from Auto which is controlled by the Victron internal relay) the day before I leave and turn on refrigerator.

[CHICKDOE]

to titan,

so you are saying wire the shunt so it is first thing off the battery and before the battery disconnect switch. this way the shunt will never be disconnected from the battery and it should therefore always be able to keep track of the inflows and outflows from the battery, with the possible exception of internal battery self discharge. and the load from leaving the monitor always connected is so minor that it really won't discharge the batteries while in storage.

the monitor will recalibrate itself once you fully recharge the batteries and the recharge current drops down. also, these things can't be 100% perfect as you put in your battery AH capacity when you install the monitor. but as time elapses and the battery degrades somewhat the SOC that the monitor is reporting would be based upon the initially entered AH capacity. but they still should give a pretty good indication of what is going on and the measured amps in and out should not be affected.

thanks

[NorSnrub]

I turned off battery with switch and put solar panel.

[Nomore9-5]

Looks like you've got some good advice but I'll add my 2 cents.I killed my first set of batteries by not maintaining them so after spending $ for replacements I did the following to avoid it happening again.
1. Invested in solar panel with a good quality controler( PWM) - I don't have electricity available where I store MH
2. Monthly I check batteries for fluid level, hydrometer and voltage tester

So far so good

[McCormickJim]

During the travel season, when my GT is idle for maybe 2 weeks at a time, I use a battery disconnect AT THE BATTERY. No parisitic loads. No dead batteries.

During long term storage, I still use the battery disconnect at the battery and I add a 5W solar panel for the engine battery and a 100W solar panel for the house batteries.

I also take the GT for a 10 mile walk at least monthly (twice monthly when cabin feaver sets in) when in storage. I turn on EVERYthing and let it run while on the walk. This includes the frig and generator.

[str8edg]

Thanks for the info folks. Bought a hydrometer and battery disconnect that I will connect to the negative post to the battery that runs to the chassis. I'm going to bring them down next weekend with the volt meter and check the status and install the disconnect. Hopefully they this just need a charge.