Flooded Lead Battery Maintenance While on The Road

[youngnretired]

We're getting close to embarking on our route 66 trip in our new to us 2008 Roadtrek 210 Popular. We've never owned anything like this before, nor gone on a 2 month trip in a self contained unit either.

What is the general consensus for how often to check the water level in the batteries? The two 6V batteries are new this year. Except for 2 different times of 3 days each, the van will be moving every day on this trip, and possibly plugged in for those days when we're at a particular location for more than one night. Where we stop for the night, we'll likely chose a non-powered site for the night or boondock, unless it's hot/humid and want the AC.

I'm planning on using the lower amperage charge setting on the Tripp Lite inverter and flip this to the higher amp setting if it doesn't keep the battery voltage high enough.

 

[booster]

We're getting close to embarking on our route 66 trip in our new to us 2008 Roadtrek 210 Popular. We've never owned anything like this before, nor gone on a 2 month trip in a self contained unit either.

What is the general consensus for how often to check the water level in the batteries? The two 6V batteries are new this year. Except for 2 different times of 3 days each, the van will be moving every day on this trip, and possibly plugged in for those days when we're at a particular location for more than one night. Where we stop for the night, we'll likely chose a non-powered site for the night or boondock, unless it's hot/humid and want the AC.

I'm planning on using the lower amperage charge setting on the Tripp Lite inverter and flip this to the higher amp setting if it doesn't keep the battery voltage high enough.

It sounds like with the driving everyday, (but how much time each day matters) you will probably get nearly all your charging from the engine alternator. How fast they charge and how fully they get charged depends on the voltage at the batteries, not the alternator, and the time they charge. The voltage at the batteries will be lower than the alternator by a varying amount as the charge progresses, mostly after 80% full. If have a separator the drop in voltage will be all from the wiring to the batteries and the current. If the batteries do ever get totally full the voltage will be near what it is at the separator, but that will normally take a long time of driving unless you start out almost full.

Water use depends on the lead chemistry, but if you have water caps, the likely are true deep cycle batteries and will use water depending on the above voltages and state of charge. The more time they are charging, especially if over 80% state of charge on the alternator, the more water they will use. When we had two six volt Trojans in our van, we could easily need to water them in a week or less. if the solar was doing a charge every day on top of being full from driving, for instance.

The best would be to use this trip to learn how much your particular setup uses in water during typical use and settings. When we were learning ours early on, I would check them every 3 days to see how much the water changed and when we needed to add. The Trojans had a very large water reserve, but they also used a lot of water when in use. At golf courses that use them in the carts, they water them every day and fully charge overnight, every day.

 

[TX-Trek]

Last year we went through Adrian TX, midpoint of route 66 as part of our trip. We've also got two lead acid 6v batteries that are pretty much constantly charged except for stops during driving. We don't boondock, so all batteries are charged while driving and when overnighted somewhere connected to shore power.
Booster is right, the more they charge the more water they use. I check them every 2-3 days and add distilled water as needed. Water usage isn't terrible but it can catch up on you if left them unchecked for a week or so.

We're about to head out ourselves in a couple of weeks for a 4-5 week roadtrip.

 

[TooMuchHair]

Just to add, flooded lead acid batteries like being fully charged, unlike lithium iron batteries.

 

[SQUASHMIRE]

Start with batteries full and check in a week. If still full, wait longer the next time. I've not seen big drops in month-long trips, but maybe.

What you will like is a battery shunt like the Victron 300Amp. You can use your phone to tell exactly how charged your battery is, how many amps you have left to either use or charge.....assuming you don't already have an equivalent monitor.

 

[topwop]

We have a 06C210P with 2 6v golf cart batteries and just finished a 32 day, 8900 mile, trip from Ohio to Washington then through Oregon, California, Nevada, adnso on back home to Ohio. We did it about the same way that you plan on doing your trip, traveling almost every day, but most imes we plugged in overnight as we needed A/C most nights. I checked and added water only twice during the trip and both times they only took about 1 1/2 cups of water total. Hope that helps. We'll be heading out again the end of September heading for Texas, New Mexico, and Arizona maybe we'll run in to you.

 

[youngnretired]

Thank you for all the input on this. The battery will be 95%+ charged when we start out and I'll check the water level twice a week and adjust as we go along. Previously with our popup, I would check the battery once a year and all was good, but we would use that only a couple times a year, and the class B is so much different, and I just topped off both batteries (first time looking at the new batteries) and added a total of a 1/4 gallon.

As part of my replacement for the missing TV, I installed a multi-outlet cigarette lighter port in the media cabinet to power the 12V DC TV and a future audio/video controller. Since I had an empty port, I stuck in a USB cord adapter that also has a voltage gauge on it. This will be my only way of monitoring the charge status of the coach batteries inside the vehicle, except for the stock Roadtrek panel that only gives lights for state of charge. The USB charger adapter is an el cheapo Chinese piece, so it's probably not too accurate compared to a real voltmeter and it's checking voltage a ways from the battery and thru multiple connectors that exist, but it at least gives me a voltage number, not just a bank of idiot lights.

If I see another Roadtrek in a campground, I'll stop over and maybe our paths will cross on one of these excursions.

 

[booster]

I think you will find that your batteries are not completely full, when you think they are unless they have been on absorption voltage charging for at least 8 hours from about 50% SOC or less if more full. The problem comes at the end of charging when it can take 4+ hours to go from 85% SOC to 100%.

Voltage will not tell you if they are full and is only a general reference point for points other than full. Even off full the batteries need to be unloaded and rested for at least an hour before testing and it is still not all that accurate. The only ways I know to check full charge is be looking at the amps to the batteries at full charge voltage, or in the case of wet cells that have caps, checking the specific gravity with a liquid tester.

The above is the reason you see so very many of us recommending a shunt based battery monitor so you can tell nearly exactly what SOC your batteries are at and see the amps going to and from the battery. Two newer deep cycle wet cells of about 200ah rating will not be full until they are charging at somewhere around 4 amps total to the batteries at absorption voltage. RV charging equipment is generally unable to do this kind of charging and will either short charge them (less chance of damage) by going to float early, or overcharge them by going to float to late. Most manufacturers charge short as it causes slow loss of capacity, while overcharging can kill them quickly.

Solar controllers can also be an issue as some of them do a full charge every day whether the batteries need it or not. If the batteries are full and they get charged for whatever hours the controller does, it can cause damage or at least heavy water use. I saw this first hand when we had a Morningstar controller.

Driving long distances with the charging on and batteries full can also overcharge the batteries and can be minor if you have lower voltage in the van charging or not so good if it is high. Our stock Chevy would run at quite high voltage for long periods of time, so I used an ammeter on the dashboard reading battery amps and shut off the separator when the batteries got full while driving.

 

[youngnretired]

I'll be taking our hydrometer on the trip to check the batteries. The voltage reading inside the cab will be used as a base point to have some sort of idea of where things stand on such a long excursion as this and this all being new to us. It's not a perfect scenario, but with time and money getting short, I can't install a shunt based system this year, maybe next year.

 

[TX-Trek]

Been on the road for about a week now with batteries getting charged both when driving and stopped at a park or rv park. I filled the wet cell batteries when we left and added a bit of bottled water to get them up to the bottom of the openings. Not too low but they were lower than when we left. Both batteries took a total of about half a bottle or so.
I put a nail hole thru the bottle top, makes it easy to squirt water into each cell without making a mess.
About a year ago I also replaced the cell vent caps with new, helps keep the tops dry.
Voltage is typically 14.5 to 14.8 when driving and 13.45-.48v when parked (hooked up). No problems with stopping to see a sight for a couple or few hours - the fridge stays on during that time.
I've installed one of these, not expensive and has worked well.

I used a plastic project box to mount it next to the van power panel. Depending on which polarity you mount it to, it will read input or output. I've got the shunt mounted on the positive side, this is the reading when connected to shore power.