Battery Life, Charging Methods

[gypsmjim]

We have been boondocking 100% with our new 2015 Jayco 195RB since August. We're permanently set up on our own property 100 miles from home - no utilities available. That's the way it will stay forever! The battery that came with the unit is a Interstate 24 Dual purpose. I run the Yamaha generator maybe an hour in the morning during breakfast and then 3-4 hours later in the day. We are there weekends only, sometimes 2 weeks apart. The charging shows about 13.6 volts. I have a battery disconnect switch to turn everything off when we're not there.

The first month or so the battery showed about 12.4 volts when we returned after a week. It has been progressively getting lower each week. I suspect I'm not getting a full charge before we leave.

This week we had only 11.8 volts Saturday evening when we got there. Watched a little TV and it dropped to 8 volts. To my surprise, with the tstat set at he lowest seting, and with outside temp at 31 F, the furnace operated like a champ all night. It was still 8 volts in the morning before I fired up the generator.

Sooooo, my questions....
1. If I switch to a deep cycle size 27 battery (not a dual purpose), how much better life will I get?
2. I have a good automatic 3-stage battery charger - would this charge it up quicker than the onboard inverter?
3. If so, can I connect the charger directly to the battery without unhooking it from the trailer? Is it a problem if the 2 chargers are connected at the same time?

[cariboocreek]

Sounds like a perfect candidate for solar.

[gypsmjim]

Originally Posted by cariboocreek

Sounds like a perfect candidate for solar.

I knew someone would say that.....LOL. Our campsite is heavily wooded with tall trees. At best the trailer only sees sunlight a couple hours a day.

[Wrascal]

I can't answer your questions but do have a suggestion ... install a second battery in parallel.

Also, I've seen advertised, mounted/portable solar cells with long cords, designed to be carried out to a sunny spot (limited of course by the connecting wires).

[Wrascal]

Heres one: http://www.amazon.com/Renogy-Foldabl...e+solar+panels

[SkyBound]

A lot of guys including myself have gone to two 6V golf cart batteries wired in series. A good quality (not stock) charger/converter replacement is necessary as well, with smart mode or true 3-stage charging capabilities. This will allow your generator to charge up your batteries to a reasonable level (~90%) in a more realistic time frame, like 4 hours, versus likely over 12 hours with the lousy stock charger/converter unit.

By going to twin 6V batteries your capacity will more than triple. Just be careful to never run them down below about 11.9V or even 12.0V.

[Big Sky]

X2 on what SkyBound said.

Go with 6 volt deep cycle batteries in series, look at your stock converter model and contact manufacturer of the converter to determine if it can be upgraded with a plug in module to make it an advanced 3-stage charger.

I would also highly recommend installing a Trimetric battery monitor so you have a better way of monitoring your state of charge other than voltage. A volt meter can give you a false indication on the true state of the batteries. In other words it may show 13.5 volts but you may only be at 70% of amp hour capacity on the battery bank.

[Mustang65]

Originally Posted by gypsmjim

This week we had only 11.8 volts Saturday evening when we got there. Watched a little TV and it dropped to 8 volts. To my surprise, with the tstat set at he lowest seting, and with outside temp at 31 F, the furnace operated like a champ all night. It was still 8 volts in the morning before I fired up the generator.

Sooooo, my questions....
1. If I switch to a deep cycle size 27 battery (not a dual purpose), how much better life will I get?
2. I have a good automatic 3-stage battery charger - would this charge it up quicker than the onboard inverter?
3. If so, can I connect the charger directly to the battery without unhooking it from the trailer? Is it a problem if the 2 chargers are connected at the same time?

You have pretty much killed your battery by letting the voltage drop below 12VDC. 12VDC is 50% of your batteries power. 12.6VDC is a fully charged battery. You are starting your weekend with a battery that will probably need 6 hours of charging at the minimum. There are charts on this site that show you this information. Deep cycle batteries can not survive for any length of time being discharged this low. You also need to learn how to cut your energy usage.

Your current battery will not get you through a weekend, let alone one day, as it is not fully charged when you arrive.

The TT furnace will drain a battery FAST. 3 hours is not enough time to charge your battery, and will not charge your future larger batteries. Do you have LED's in the TT? Only use lights at night? No charging phones off batteries!

Based on your camp site comment, SOLAR is definitely out of the question.

Upgrading to more battery power will be expensive, and if you do not figure out how to properly maintain/charge your batteries, you will be throwing away hard earned $$$. The bigger batteries you purchase will require longer charging time....

Are you running an inverter? If so what size?

Do you keep the battery water level where it should be?

One thing to remember when buying deep cycle batteries, the Ah rating is 100% usage of the battery, which will kill them fast. As my batteries are rated at 260Ah, but since I do not use the batteries below 12VDC, (50%), I actually only have 130Ah available. When you plan your future purchase keep that in mind.

Just my thoughts,

Don

[Bassdogs]

x3 on Skybound.

First loose the dual purpose battery, not the right tool for the job. Then get dual cart batteries or at least 2 good 12v deep cycle. Finally run the gen 2 or 3 hours in the am and evening to top off the battery and keep it above the 50% discharge level.

No one should expect to "boondock" using your set up.

[gypsmjim]

Originally Posted by Mustang65

You have pretty much killed your battery by letting the voltage drop below 12VDC. 12VDC is 50% of your batteries power. 12.6VDC is a fully charged battery. You are starting your weekend with a battery that will probably need 6 hours of charging at the minimum. There are charts on this site that show you this information. Deep cycle batteries can not survive for any length of time being discharged this low. You also need to learn how to cut your energy usage.

Your current battery will not get you through a weekend, let alone one day, as it is not fully charged when you arrive.

The TT furnace will drain a battery FAST. 3 hours is not enough time to charge your battery, and will not charge your future larger batteries. Do you have LED's in the TT? Only use lights at night? No charging phones off batteries!

Based on your camp site comment, SOLAR is definitely out of the question.

Upgrading to more battery power will be expensive, and if you do not figure out how to properly maintain/charge your batteries, you will be throwing away hard earned $$$. The bigger batteries you purchase will require longer charging time....

Are you running an inverter? If so what size?

Do you keep the battery water level where it should be?

Just my thoughts,

Don

All the lights are LED - use no more than 1 at a time and then only at night. Never charge phones. The only other usage is a TV, and maybe no more than an hour at night. battery IS properly maintained (water, etc).

The trailer we had before this one had NO power at all, so we have learned to be conservative. Of course,a furnace is a necessity.

The comments about solar have gotten me to rethink it. I COULD put it on a post in a sunnier area. How many hours a day does it need sun to be effective?

What doi you man by inverter? I have the stock unit that came with the trailer. My generator is a Yamaha Inverter 2800.

[Mustang65]

Originally Posted by gypsmjim

The comments about solar have gotten me to rethink it. I COULD put it on a post in a sunnier area. How many hours a day does it need sun to be effective?

What doi you man by inverter? I have the stock unit that came with the trailer. My generator is a Yamaha Inverter 2800.

Glad to hear that you already conserve energy. Most people dry-camping have to go through a the learning process..

As for the inverter, converting 12VDC to 120VAC. I have a 1500 watt inverter and have never maxed it out (so far in just under 2 years). Large units can have an internal 1-3 amp drain, just in itself.

You are better off using the TT's internal battery charge controller to charge your battery (hooking generator to TT's 120VAC connection).

As for SOLAR, you need to figure out how many hours of DIRECT sunlight the SOLAR panel(s) will have. You can then calculate the size and number of panels you will need. I would recommend that you DO NOT buy the LOW VOLTAGE panels (usually about 17-24VDC, sold in kits. Buying a HIGH voltage panel (about 31VDC) will cost you less per watt and coupled with an MPPT SOLAR charge controller will out perform any low voltage setup (unless you buy a lot of low voltage panels).

A major issue in SOLAR is the distance between the SOLAR panels and the TT's batteries. The distance may be to far and the voltage drop may be to great. If you do calculate it out, the longer length of wire should be between the panel and the SOLAR charge controller, and the shorter run between the SOLAR charge controller and the batteries.

I have one 250Watt Grape Solar (31VDC high voltage purchased at HomeDepot - Free shipping, cheapest at time of purchase) panel, which is the one used for home solar applications and a MorningStar MPPT 60 charge controller. I have direct sun on the panel from 11AM-5PM. I do not let my batteries drop below 12VDC and they are charged by 2 PM each afternoon, 3-4PM if cloudy). I will be adding 1 or 2 more panels and 2 more T145 Trojan batteries by next camping season. I chose the MorningStar MPPT controller because I can check my live status (on my smart phone) and the availability to look at 120 days of history. This helps to see if anything is going wrong.

Good luck
Don

[gypsmjim]

Mustang, thanks for the continued support.

OK, been looking at what you've suggested - a little pricey....LOL. Especially since our electric usage is minimal.

So, here's the deal....Let's say I buy a ~$300 starter kit with a MPPT controller. Also, let' say the battery is at about 12.2 volts at the end of the day when I turn off the disconnect switch. With my situation, say I only have 3 hours of direct sunlight. When I come back next weekend (5 days later) will the battery be fully charged?

I realize lots of variables here. I'm just trying to get a feel for it, so I'm not looking for a 100% answer. I know i can keep the battery up when I'm there - the genny works fine - just need to "maintain" when I'm NOT there.

Also, I knew right away I had the wrong battery. But that's what the dealer gave me for "free" and I didn't think ahead to specify what I wanted.

[SmokerBill]

You could just buy an inexpensive automotive battery charger and take the battery home with you at the end of each weekend. It would have all week to get a true, full charge. At best, running the generator for 3 or 4 hours a day is only getting the battery up to 90% charge state. That last 10% needed to reach full charge can take many more hours, and for your battery to remain healthy, it should reach full charge state regularly.

And a remote battery charger would be a lot less expensive than the solar option.

[Mustang65]

Originally Posted by gypsmjim

Mustang, thanks for the continued support.

OK, been looking at what you've suggested - a little pricey....LOL. Especially since our electric usage is minimal.

So, here's the deal....Let's say I buy a ~$300 starter kit with a MPPT controller. Also, let' say the battery is at about 12.2 volts at the end of the day when I turn off the disconnect switch. With my situation, say I only have 3 hours of direct sunlight. When I come back next weekend (5 days later) will the battery be fully charged?

I realize lots of variables here. I'm just trying to get a feel for it, so I'm not looking for a 100% answer. I know i can keep the battery up when I'm there - the genny works fine - just need to "maintain" when I'm NOT there.

Also, I knew right away I had the wrong battery. But that's what the dealer gave me for "free" and I didn't think ahead to specify what I wanted.

As for your batteries (new deep cycle replacements) being charged over the 5 days... I would say yes, but that is based on a good amount of sunshine over the 5 days.

Question: I know you said you would put them on a post, but what are the chances that they would grow legs during those 5 days you are not there. Is the area secure, as SOLAR panels are a hot item... you will see a lot of used ones on eBay... wonder where they got them?

Why I recommend staying away from kits without MPPT solar controllers, a little example showing the difference between MPPT and PWM:

PWM Controller:
Let's say your battery is at 12.4 volts and you have a 100 watt panel, rated at 16.5VDC your output would be close to 6 amps (6 amps * 16.5 volts = 100 watts). So if your battery is at 12.4 volts it will only charge at 6 amps (see above calculation) times 12.4 volts or only 75 watts. You reduced your capacity by 25%.

Enter the MPPT controller:
With the panel voltage being higher than the battery voltage, the MPPT controller will compensate for the difference. So if you take the lower 12.4 battery voltage the MPPT charge controller will use the FULL power of the solar panels output of 100 watts or 8 Amps. (12.4 volts * 8 amps = 100 watts).. The calculations will be slightly off due to rounding. Add a couple more 100 watt panels in series and you can do the math of the above numbers X2 or X3. My MPPT controller is capable of 150 volts input and 60 amps, so there is plenty of room for additional panels. Keep expansion in mind when buying the SOLAR charge controller.. you only want to buy it once.. as replacing it can be expensive.

An easy way to calculate PWM loss (compared to MPPT) is:
PV voltage - Battery voltage = Difference x Amps = Lost wattage

Not sure that this is the best way to go...

Sorry this was so long :-(

Hope this helps,

Just my thoughts,

Don

[CDavid]

Originally Posted by SmokerBill

You could just buy an inexpensive automotive battery charger and take the battery home with you at the end of each weekend. It would have all week to get a true, full charge. At best, running the generator for 3 or 4 hours a day is only getting the battery up to 90% charge state. That last 10% needed to reach full charge can take many more hours, and for your battery to remain healthy, it should reach full charge state regularly.

And a remote battery charger would be a lot less expensive than the solar option.

This seems like a really simple fix to your problem since you said that you only go for weekends, or better yet, have a spare battery, take it in with you, then just swap it out. Just keep swapping out with a fully charged battery. I guess the only downside to this, is that you have to transport a fully charged battery around.....probably should do that in a secure method.....maybe in battery box with a lid. Good luck!

[gypsmjim]

When I was younger and not as lazy (LOL) swapping batteries would not have been an issue. Now, we often get down late Friday night, and I don't relish changing out batteries in the dark.

Sprouting legs is always a problem. The solar panels would be the least of my worries. With a bolt cutter they can have a lawn tractor, generator, 4-wheeler and a lot of other stuff. We have been there 27 years and (knock on wood) have not has a single problem yet.

[Big Sky]

I'd keep it simple. Check out your existing stock converter that currently charges your battery. I highly doubt it is an advanced 3-stage charger, however it may very well have the ability to be upgraded. That is your least expensive route. If that is not the case, then you should take a look at getting an external battery charger you can use to charge for 3-4 hours per day with your generator. That is exactly what I did for years before I upgraded my charging system. Do not get one that automatically reads the voltage and turns off automatically. Get a farm & ranch you can set on 30 amps and force feed your battery for 3-4 hours straight.

Found this link from the forum, posted in 2011. All holds true today. Check it out.

http://www.kissmygrits.net/factory-r...d-boondocking/

Good luck.

[Bassdogs]

Originally Posted by gypsmjim

All the lights are LED - use no more than 1 at a time and then only at night. Never charge phones. The only other usage is a TV, and maybe no more than an hour at night. battery IS properly maintained (water, etc).

The trailer we had before this one had NO power at all, so we have learned to be conservative. Of course,a furnace is a necessity.

The comments about solar have gotten me to rethink it. I COULD put it on a post in a sunnier area. How many hours a day does it need sun to be effective?

What doi you man by inverter? I have the stock unit that came with the trailer. My generator is a Yamaha Inverter 2800.

Really think you are putting way too much thought into this for a trailer that you say has a very low power usage. Solar by any account is expensive to set up. A couple good deep charge batteries, a simple auto battery charger available at Wally World and the generator you already have and your good to go. You can use all the lights, tv/radio, charge your stuff, and use your furnace without putting more than a moderate strain on your batteries. 2 or 3 hours in the am and again in the evening will keep your batteries topped off and allow you to leave your batteries full when you leave on Sunday. You can not justify the $$ necessary to put together a decent solar system for the type usage you have described.

[gypsmjim]

Originally Posted by Big Sky

I'd keep it simple. Check out your existing stock converter that currently charges your battery. I highly doubt it is an advanced 3-stage charger, however it may very well have the ability to be upgraded. That is your least expensive route. If that is not the case, then you should take a look at getting an external battery charger you can use to charge for 3-4 hours per day with your generator. That is exactly what I did for years before I upgraded my charging system. Do not get one that automatically reads the voltage and turns off automatically. Get a farm & ranch you can set on 30 amps and force feed your battery for 3-4 hours straight.

Found this link from the forum, posted in 2011. All holds true today. Check it out.

http://www.kissmygrits.net/factory-r...d-boondocking/

Good luck.

I'm not an expert on these newfangled trailers, but I know a little bit about deep cycle batteries and such, having owned boats for the last 45 years.

If you "force feed" a battery at 30 amps for 3-4 hours wouldn't you literally boil it over and destroy it after you did that a few times? Once I had an alternator malfunction and the over-charging literally killed the battery.

[Big Sky]

You will not over boil in 3-4 hours a battery that was run down the night before. My golf cart batteries were charged this way for four seasons. This last season I finally upgraded and replaced my charging system. Now the batteries are on an advanced 4-stage charging system. Finished season five with them and hope to get 6 or 7 years before they are done. It charges at a bulk 100 amps and eventually floats at 1.5 amps. Full charge with that system takes 3+ hours depending on initial state of discharge. However if you charge at 30 amp for four hours straight, you will not over charge your battery.

The best step one mod investment for you would be a battery monitor. That will give you the ability to always understand exactly the charging state of your batteries and put your mind at ease from over charging as well as over discharging.

What is the brand and model of the converter that came with your TT? Let's start there first. Let's investigate if it has an advanced upgrade option. That's your best bet!