Battery maintenance

[pgandw]

Originally Posted by NavyLCDR

On most battery disconnect switches, the "ON" position means the battery is connected, the battery is turned "ON". The "OFF" position means the battery is turned "off", it is disconnected from the loads on the load side of the switch. Sometimes the disconnect switch will have another position that allows you to remove the "key" or handle when in the "OFF" position with the battery disconnected.

From the factory, the propane leak/CO detector will be wired to the battery itself and not disconnected with the switch which will draw a small load off the battery.

This is a popup camper. They do not come standard with a battery cutoff switch. So wiring of the cutoff switch on a popup depends on the installer. Most home installations of a battery cutoff cutoff everything, either at the battery post or at the battery box.

The propane/CO detector in a popup is wired into the DC fuse panel, and not directly to the battery. The electric roof lift and emergency brake switch may/may not be wired directly to the battery. If not, they bypass the fuse panel, and connect at a junction on the trailer tongue.

Fred W
now 2019 Flagstaff T21TBHW A-frame
then 2014 Rockwood A122 A-frame
then 2000 Coleman 12ft box popup
2022 Hyundai Palisade

[NMWildcat]

Originally Posted by pgandw

This is a popup camper. They do not come standard with a battery cutoff switch. So wiring of the cutoff switch on a popup depends on the installer. Most home installations of a battery cutoff cutoff everything, either at the battery post or at the battery box.

The propane/CO detector in a popup is wired into the DC fuse panel, and not directly to the battery. The electric roof lift and emergency brake switch may/may not be wired directly to the battery. If not, they bypass the fuse panel, and connect at a junction on the trailer tongue.

Fred W
now 2019 Flagstaff T21TBHW A-frame
then 2014 Rockwood A122 A-frame
then 2000 Coleman 12ft box popup
2022 Hyundai Palisade

None of my pop-ups, TTs, or fifth wheels came with factory battery cutoffs. Of course, most of the new ones seem to come with partial cutoffs now. And they all came with only one battery.
The first thing anybody that will boondock should do is install (or at least have in possession) 2 batteries, a complete battery cutoff, and have a way to recharge your batteries.
Makes life a lot easier.

[2WheelJon]

Originally Posted by chriscowles

OK, I'll bite. What does that mean?

Darn spell checker. That should read “occasionally”

[chriscowles]

Originally Posted by 2WheelJon

Darn spell checker. That should read “occasionally”

It worked out better for us that it didn't.

[chriscowles]

Originally Posted by NMWildcat

None of my pop-ups, TTs, or fifth wheels came with factory battery cutoffs. Of course, most of the new ones seem to come with partial cutoffs now. And they all came with only one battery.
The first thing anybody that will boondock should do is install (or at least have in possession) 2 batteries, a complete battery cutoff, and have a way to recharge your batteries.
Makes life a lot easier.

My 2000 Coleman Mesa had one but I think it was more for safety than to conserve the battery.

It had a cantilevered kitchen. When swung down into the aisle when closing the camper, a spring-loaded switch under the upper cabinet half opened. By cutting off the power, the incandescent ceiling light couldn't cause a fire when closed.

[Jim CB]

No, trickle charges are horrible for batteries, get a smart charger made by Battery Tender. Think about the battery for your daily driver. The battery charges when driven and slowly drains when stationary. This is how they are able to last for 5-6 or more years. A Battery Tender does the same thing, lets it drain slowly to a point, then charges it right back up and cycles this over and over. I use them on my motorcycles and get 5-6 years per battery. The Battery Tender will pay for itself in just a couple of years by preventing the need to buy a new battery every 2-3 years.

[mnoland30]

Unless it is stored inside, your best option is to put a cheap battery disconnect (Harbor Freight) on the battery post, and a 5 watt solar panel made to go on the dash.

Your battery has a limited number of discharge cycles before it is toast. If you keep the battery topped off all of the time, it will last a long time. The battery in my old truck (which I hardly drove) lasted 10 years with a solar charger on the dash.

Many of the new panels come with two ways to connect, a cigarette lighter plug, or ring eye terminals that hook to your battery. When traveling, you just unplug. A better option might be to mount it permantently.

[2WheelJon]

All the advice here is good except the OP never stated (not that I could find) what type of battery he has. Maintaining lead-acid batteries would require a smart charger to keep them topped off. Yes, Batter Tenders are good for this and I have two for my motorcycles. LiFePO4 batteries, however, are different. They have very low internal drain and as such do not need constant charging. They also like to be stored around 50% SOC instead of topped off like lead-acid.

So, what kind of battery are we talking about.

[flyerdp]

I use a battery maintainer with drop down to trickle charge capability once fully charged.

Word of warning, if the battery is near end of life and it won't reach a full charge you may end up boiling out the water because the charger can't detect the full charge and continue to hit it with higher current trying to reach peak charge.

[NavyLCDR]

Originally Posted by flyerdp

I use a battery maintainer with drop down to trickle charge capability once fully charged.

Word of warning, if the battery is near end of life and it won't reach a full charge you may end up boiling out the water because the charger can't detect the full charge and continue to hit it with higher current trying to reach peak charge.

The good ones have a 4 hour time-out on the boost charge.

[flyerdp]

Originally Posted by NavyLCDR

The good ones have a 4 hour time-out on the boost charge.

I dont think harbor freight often falls in the "Good" category... mostly "sufficient"

[p_miles]

I have had bad experiences with trickle chargers in the past. If the charger is a non regulated charger it can boil the battery electrolyte and destroy the battery. If you only use it occasionally then that is probably ok. What I have done is to use a smart regulated charger, the one I use is a genius charger from NOCO, get a small one, they are very inexpensive. I dont use it on my trailer, but when we travel I connect one to a riding lawn mower, one for a tractor and one on my wife's car. I have used them for several years now and have no had any issues. My travel trailer has a lithium battery, I bring it inside when not using the trailer, it does not care if it is charged or not. One of the chargers I have will charge lead acid or lithium and I have occasionally charged the trailer battery with it. It senses either Li or Lead acid and charges appropriately.

Hope this helps Peter

[Boemer Bunch]

Thanks for everyone’s responses. I have gone with the following items to monitor my battery and the health.

https://a.co/d/hYFvhY1



https://a.co/d/6FAaUBw

[chriscowles]

Originally Posted by Boemer Bunch

Thanks for everyone’s responses. I have gone with the following items to monitor my battery and the health.

https://a.co/d/hYFvhY1

If the battery monitor does not incorporate a shunt, through which all current passes, it will be far less accurate than is useful.

[NavyLCDR]

Originally Posted by chriscowles

If the battery monitor does not incorporate a shunt, through which all current passes, it will be far less accurate than is useful.

Obviously you and I agree. But the battery monitor based on voltage alone can be useful - it's just that to get an accurate indication of the state of charge of the battery it has to be "at rest" for several hours, which is inconvenient when boondocking because you have to isolate the battery from charging sources as well as more than parasitic loads for several hours.

The voltage reading will tell you if your charging source is charging the battery, though.

[pgandw]

Originally Posted by chriscowles

If the battery monitor does not incorporate a shunt, through which all current passes, it will be far less accurate than is useful.

Again, the use case is an A-frame. There simply are not large DC loads to give a hopelessly inaccurate idea of battery SOC by reading voltage. But there is a small load at all times - CO/propane detector (0.2A) that will rapidly kill off any surface effect within the cell.

I know this from real life experience with my A-frames. At most, my battery will read 0.1V lower than if I let the battery sit for six hours unloaded. With a lead acid battery, each 0.1V is pretty close to 10% charge - starting at 12.1V = 50% SOC. 12.6V is approx 100%. If a LiFePO battery is chosen, then AH in/out is a better choice. You have a much more expensive battery that deserves the extra care of a better monitor.

Being off by 10% SOC is just not that big a deal in the world of A-frames. And the nice thing about using battery voltage with the battery lightly loaded is that the battery lower voltage will read slightly lower than it really is.

As an electrical engineer, I enjoy geeky toys. But when I am camping - especially in an A-frame - the goal is to make the camping experience as pleasant as possible while minimizing expense and inconvenience. Not play with my geek toys. So I simply install a dual battery bank using Costco GC-2 batteries at less than $100 each, use a $7 volt meter to approximately check battery SOC once a day, and do not carry a generator or solar panels. By the time my battery bank is down to 50% when dry camping, I am running out of water in the tank and refrigerated food. And it's time to move on and resupply. An A-frame lends itself to short stays and moving on.

Different camping styles for different folks

Fred W
2019 Flagstaff T21TBHW A-frame
2022 Hyundai Palisade
last trip - MCAS Cherry Point, NC

[NavyLCDR]

Originally Posted by pgandw

Again, the use case is an A-frame. There simply are not large DC loads to give a hopelessly inaccurate idea of battery SOC by reading voltage. But there is a small load at all times - CO/propane detector (0.2A) that will rapidly kill off any surface effect within the cell.

I know this from real life experience with my A-frames. At most, my battery will read 0.1V lower than if I let the battery sit for six hours unloaded. With a lead acid battery, each 0.1V is pretty close to 10% charge - starting at 12.1V = 50% SOC. 12.6V is approx 100%. If a LiFePO battery is chosen, then AH in/out is a better choice. You have a much more expensive battery that deserves the extra care of a better monitor.

Being off by 10% SOC is just not that big a deal in the world of A-frames. And the nice thing about using battery voltage with the battery lightly loaded is that the battery lower voltage will read slightly lower than it really is.

As an electrical engineer, I enjoy geeky toys. But when I am camping - especially in an A-frame - the goal is to make the camping experience as pleasant as possible while minimizing expense and inconvenience. So I simply install a dual battery bank using Costco GC-2 batteries at less than $100 each, use a $7 volt meter to approximately check battery SOC once a day, and do not carry a generator or solar panels. By the time my battery bank is down to 50% when dry camping, I am running out of water in the tank and refrigerated food. And it's time to move on and resupply. An A-frame lends itself to short stays and moving on.

Different camping styles for different folks

Fred W
2019 Flagstaff T21TBHW A-frame
2022 Hyundai Palisade
last trip - MCAS Cherry Point, NC

Again, I will ask, "How do you know that state of charge of a battery based upon voltage when there is source charging the battery?" You know exactly 1 thing - the charging voltage being supplied by the charger. I discharge my battery to 50%. I start my genny to charge my battery, or the sun rises and my solar panel starts charging my battery. After 5 minutes the voltmeter reads 13.3 or more volts and 100% battery state of charge. Is that accurate after 5 minutes of charging a battery that was at 50% state of charge? No. And it doesn't matter if the battery is connected to a 50' long 5th wheel or a 15' long A-frame trailer. If you are going to only measure voltage, there are a lot cheaper ways of doing so than a falsely advertised "battery monitor" that is only going to measure voltage only.

[pgandw]

Originally Posted by NavyLCDR

Again, I will ask, "How do you know that state of charge of a battery based upon voltage when there is source charging the battery?" You know exactly 1 thing - the charging voltage being supplied by the charger. I discharge my battery to 50%. I start my genny to charge my battery, or the sun rises and my solar panel starts charging my battery. After 5 minutes the voltmeter reads 13.3 or more volts and 100% battery state of charge. Is that accurate after 5 minutes of charging a battery that was at 50% state of charge? No. And it doesn't matter if the battery is connected to a 50' long 5th wheel or a 15' long A-frame trailer. If you are going to only measure voltage, there are a lot cheaper ways of doing so than a falsely advertised "battery monitor" that is only going to measure voltage only.

You are correct - when plugged in, I only know the voltage the battery is being charged at - with a $7 voltmeter. My converter voltage varies depending on the state of charge the converter assesses the battery is in. If the battery is low, the converter will jack the charge voltage up to around 14.2-14.4V in an effort to bulk recharge the battery. After time and/or battery resistance has built up, the charge voltage is dialed back to 13.7V (with my particular converter - PD 4135 - the factory spec sheet says this happens at about 90% SOC). When the converter senses the battery is fully charged, the voltage is again reduced to a maintenance voltage of 13.1-13.2V. So by observing charge voltage, I can have a guess of SOC.

And that's good enough for me. When plugged in, the battery is maintained by the converter, automatically. If I'm plugged in for 12 hours, I know the battery is fully charged, no matter what it started at. Since I don't use a generator or solar, the chances are that if I'm plugged in, it's overnight, and I can count on the battery being fully charged in the morning.

Yes, I could know more about my battery and its charge state by spending more money. But why? I'm camping, not running a battery shop. If I'm camping where there is electric, I don't need to monitor anything. The converter does the monitoring for me.

If I'm dry camping, I only need to ensure that I'm at a reasonable SOC when I break camp - and that only to avoid shortening battery life too much. With no generator or solar, my battery bank of 2 GC-2s was sized to run the A-frame for 4+ nights of outside temps in the 30s or higher - and it will do so through actual experience. At the end of 4+ nights of dry camping, we are also running low on water and food in the fridge. It's time to move on.

FWIW, most A-frame or PUP owners do not bother with generators or solar power. The only time I wished I had a generator was when we went group camping with our church at Lake Tahoe for 10 days. But actually I'm glad I don't have to bother with the weight, space, and refueling of a genny (or setting and aiming of solar panels).

KISS camping - my style of camping
Fred W
2019 Flagstaff T21TBHW A-frame
2022 Hyundai Palisade

[chriscowles]

Originally Posted by pgandw

... And that's good enough for me. ...

Clearly, you understand the accuracy range of your measuring instruments enough to make informed decisions. Not all who post here do.

[TitanMike]

Originally Posted by NavyLCDR

Again, I will ask, "How do you know that state of charge of a battery based upon voltage when there is source charging the battery?" You know exactly 1 thing - the charging voltage being supplied by the charger. I discharge my battery to 50%. I start my genny to charge my battery, or the sun rises and my solar panel starts charging my battery. After 5 minutes the voltmeter reads 13.3 or more volts and 100% battery state of charge. Is that accurate after 5 minutes of charging a battery that was at 50% state of charge? No. And it doesn't matter if the battery is connected to a 50' long 5th wheel or a 15' long A-frame trailer. If you are going to only measure voltage, there are a lot cheaper ways of doing so than a falsely advertised "battery monitor" that is only going to measure voltage only.

Look at the bright side. The monitor posted is probably a far better voltmeter than the factory supplied LED one and you don't have to consult a chart to determine SOC from a voltage chart. It does the calculating for you

I agree that PUP owners for the most part don't really have high demands on a battery and camp as if they are tent camping, just with easier setup and more comfortable beds