Adding a bigger house battery and solar

[opticalmike]

After just one trip with a new to us 2006 Ford excel-ts, we have decided to try to add another house battery. The current house battery is a group 24 deep cycle. Nothing fancy. I don't mind replacing that one, even though the previous owner said it was newer. It seems like the battery tray is quite small. I wish it would fit a group 27. I was hoping to add another battery in parallel to give us more reserve minutes for overnight running of the fantastic fan or furnace. Also, I would like to add some solar...to minimize our use of the 2.8 onboard Onan generator. The roof will not really accommodate much in the way of solar panels due to the location of the TV antenna. I was thinking of using a 110 watt flexi panel(Under the tv antenna) and maybe a secondary 50 watt panel. My last solar project was a fifth wheel and there was room for 6 85 watt panels. This class B has hardly any usable roof space. I hope someone chirps in with some ideas other than the suitcase solar panels. I thought I would add a group 31 AGM as a second battery in parallel but due to the differences in size and amp hr wont I run into charging difficulties on the bigger battery? The first one will charge to 100 % and the second one wont get up to 100 %....or will they discharge evenly and recharge evenly?
Any have the same class B that has some proven ideas?
TIA
mike

[Roadtrek Adventuous RS1]

Originally Posted by opticalmike

After just one trip with a new to us 2006 Ford excel-ts, we have decided to try to add another house battery. The current house battery is a group 24 deep cycle. Nothing fancy. I don't mind replacing that one, even though the previous owner said it was newer. It seems like the battery tray is quite small. I wish it would fit a group 27. I was hoping to add another battery in parallel to give us more reserve minutes for overnight running of the fantastic fan or furnace. Also, I would like to add some solar...to minimize our use of the 2.8 onboard Onan generator. The roof will not really accommodate much in the way of solar panels due to the location of the TV antenna. I was thinking of using a 110 watt flexi panel(Under the tv antenna) and maybe a secondary 50 watt panel. My last solar project was a fifth wheel and there was room for 6 85 watt panels. This class B has hardly any usable roof space. I hope someone chirps in with some ideas other than the suitcase solar panels. I thought I would add a group 31 AGM as a second battery in parallel but due to the differences in size and amp hr wont I run into charging difficulties on the bigger battery? The first one will charge to 100 % and the second one wont get up to 100 %....or will they discharge evenly and recharge evenly?
Any have the same class B that has some proven ideas?
TIA
mike

Hi Mike... you might want to look at Zamp Solar panels... we have a 160 watt panel on our roof, but, you can also get some smaller 80 watt panels from them... cost is more per watt, but, you can organize the smaller ones on the roof more efficiently in less space.


Plus, Zamp is a leader in this technology.

I agree... NO suitcase solar... it's too easily run over, stolen, trip hazard, etc.


Good luck.

[Phoebe3]

We have the GoPower flexible panel system. They were responsive to our questions and have panels sized from 30 to 100 Watts each.
https://gpelectric.com/product-category/rv/

[markopolo]

Mixing batteries, mixed wire sizes, and mixed wire length all contribute to making it difficult or perhaps impossible to optimally care for your batteries.

That said, I still do it. I think AGM's are a bit more tolerant to abuse than wet cells. I also think a continuous or near continuous controlled float charge from plugging in or from solar will help level out the imbalance.

The mixed setup won't last as long as a perfectly setup system but you still would likely get many years use out of the system. Maybe 5 instead of 7 or 7 instead of 10 years as examples.

I wouldn't purchase expensive brand batteries knowing that they'll get less than perfect care. Lead Acid batteries including AGM's are relatively cheap when the cost is spread out over 5, 7 or 10 years.

[SteveJ]

I would suggest a power budget so you know how much power is being used. Do you have LED lighting? I/we use about 15 to 25 per day, with a a newer absorbtion fridge with a circuit board.

It's possible that the previous owner was not battery friendly. A fresh battery can lose capacity fairly quickly if not treated right, just saying.

On TDY near Greenville CA next stop near Tahoe.

[booster]

A single group 24 can work for some folks, and many have survived on them in the past. That said, most of us us more power than in the past with lots of recharging of devices, etc.

It is usually best to start out by making a list of what you need power for, and how much power the items use. Then take a look at easy power reductions like LED lights or efficient TV, etc

You can then see how the power use matches your camping pattern, and available charging times. If you move nearly every day, most of your charging will come from the engine. If you have shore power all the time, most will come from that.

Some people will find a single battery fine, most seem to do well with two batteries, and some will want to have much more than two, so it is very user specific.

You will find lots of these types of evaluations and decisions on this forum if you do some searching.

[VanFan]

Don't know if they will fit your roof, but the Renogy 160 watt panels are only 60.63" x 25.98" which is the best watts-to-square inch ratio I've found. Two of them will fit on my custom Promaster build, which also has a roof mounted A/C, Maxxaire fan, and a couple of antennas. You can buy them for $390 each at Amazon. Go there and search for "Renogy RNG-160DB-H"

Also, since interior space is an issue you might be able to double your effective battery amp hours in the same footprint if you replace with lithium. Even if the posted amp hours are the same as what you have, the charge and discharge profiles should deliver a lot more usable energy. You would also need to replace your charger with one that's compatible with lithium. Depending on the amp hours in your existing battery versus the new lithium you might also need to upsize the wires between charger and battery, and battery and inverter.

if you're ever going to do it, now while you're adding solar would be a good time since you would also need a lithium compatible solar controller. You probably already thought of lithium, and might not want to spend the extra money, but I figured it wouldn't hurt to mention it just in case.

Good luck!

[opticalmike]

My problem with Lithium is we live in Northern Canada where it freezes in September. I would love to convert to lithium but realistically a second battery somewhere and a couple of 100 watt panels would really help the cause. Originally I thought I could find some space in one or two of the exterior storage areas to add a couple of 6 volt golf cart batteries which would give me an extra 220 AH.

[VanFan]

The thoughts of most normal mortals don't turn to camping in a RoadTrek when it's cold enough to freeze a battery, but there's no telling what you Canucks are likely to do for fun up there in the Great White North. Possibly you're dreaming of driving it out onto a lake, drilling a hole in the ice, and dropping a line so you can wait for a nibble while icicles dangle from your nostrils. Of course any battery can freeze under those conditions if not kept fully charged. But I know what you mean. Lithium batteries are particularly susceptible.

We set ours on a 180w battery heating pad in a small insulated internal compartment. The pad is controlled by a programmable 120v outlet thermostat. As long as the van has at least 15a of power, the insulation and heat pad should protect the battery down to well below freezing. And the battery's power management system would shut it down if it ever did get cold enough to cause damage, which is a safety feature you don't get with a gel cell, AGM, or wet cell battery.

[opticalmike]

Where did you get your Lithium and what might the approximate cost be?
I have been checking the chinese ebay known as Aibaba. Im certain most US inventory is coming from there and it might be cheaper to order direct and avoid the Trump Tariffs that are in the news.

[VanFan]

We have a 600 amp hour battery from Elite Power Solutions, which is available through Starlight Solar Power Systems here:

GBS 200AH Cells

As you'll see, they sell in 200 amp hour increments. Their system requires some assembly of the battery management system, so you'll either need to know your way around electrical systems pretty well, or hire a local electrician to do the install. Prices are shown at that link.

One thing that's kind of fun is, you can display the battery status on the monitor of your choice. We wired ours into our TV.

[hbn7hj]

These are just opinions.

The first thing you need is a better way to use what you have.

1. You need a battery monitor. I use the Bogart Trimetric,
there are others.
2. If your coach does not have a lead acid battery charger
that goes through the three stages of bulk, absorption and
float, you need one.
3. A DC to DC charger to get full use of the car alternator. We
just installed a Kisae 1230 in a truck and camper and are
pleased. Start the engine and you have 30 amps going to
your battery. The 1230 is also a solar controller for the
future.

That ought to get you going.

[BBQ]

Originally Posted by hbn7hj

These are just opinions.

The first thing you need is a better way to use what you have.

1. You need a battery monitor. I use the Bogart Trimetric,
there are others.
2. If your coach does not have a lead acid battery charger
that goes through the three stages of bulk, absorption and
float, you need one.
3. A DC to DC charger to get full use of the car alternator. We
just installed a Kisae 1230 in a truck and camper and are
pleased. Start the engine and you have 30 amps going to
your battery. The 1230 is also a solar controller for the
future.

That ought to get you going.

Agreed.

Good advice.

[cruising7388]

Originally Posted by hbn7hj

These are just opinions.

The first thing you need is a better way to use what you have.

1. You need a battery monitor. I use the Bogart Trimetric,
there are others.
2. If your coach does not have a lead acid battery charger
that goes through the three stages of bulk, absorption and
float, you need one.
3. A DC to DC charger to get full use of the car alternator. We
just installed a Kisae 1230 in a truck and camper and are
pleased. Start the engine and you have 30 amps going to
your battery. The 1230 is also a solar controller for the
future.

That ought to get you going.

One thing that the Trimetric SOC meter has in common with most digital meters is that the shunt has to be positioned in a single negative lead. If the system has multiple battery negative leads, (Etrek is a classical example) this is a problem. However, there is a SOC meter which resolves such a problem made by Blue Sea which permits installing their meter shunt in either a negative lead or alternatively in the positive bus with less than a 4% degradation in accuracy. Some installations make using the battery positive bus a more convenient shunt insertion point.

https://www.bluesea.com/products/1830/M2_DC_SoC_Monitor

[opticalmike]

Thanks all for some fantastic tech advice! Has anyone seen a bluetooth battery sensor that can be linked to the shunt....? Ive seen it somewhere. On my other rv, a fifth wheel, I did a midnight kid and the shunt to monitor state of charge.
The kid has a continuous readout of all pertinent info but I wish it had a wireless remote for it.

[opticalmike]

Any one tried this one ??....Victron BMV-700 Battery Monitor

[Saldar]

Originally Posted by opticalmike

Has anyone seen a bluetooth battery sensor that can be linked to the shunt....? Ive seen it somewhere.

I've been wondering about this bluetooth multimeter with phone app for a long time. In fact I asked about it here enough that BBQ thought I was a shill for the product. I'm not. I wish I had a battery monitor, but have a DH that too often says of my DIY ideas: "Look at the mess you've gotten us into this time, Sally". This product (with a shunt) could be a relatively easy monitor to install on the (under the van) batteries on the Travato. It's waterproof. I asked about shunts for it when it was for sale on Amazon, and received a clearly written reply, which I thought was a good sign. Do you think this device is too cheesy to do the job? I'd really like to be able to monitor amps in and out.

wirelessmultimeter.com

[gregmchugh]

I posted about this bluetooth battery monitor that supports an external shunt a little while ago but no one ever commented on it...

https://www.thornwave.com/products-b...%7Bad.id%7D%7D

[Saldar]

Originally Posted by gregmchugh

I posted about this bluetooth battery monitor that supports an external shunt a little while ago but no one ever commented on it...

https://www.thornwave.com/products-b...%7Bad.id%7D%7D

I'm sorry I missed your post. I would have welcomed a discussion about the Thornwave unit. The experts here already have the meter problem solved, I guess.

The Thornwave looks powerful. It does not appear to have an on/off switch (to avoid parasitic loss) or logging. I believe the "Wireless" does. If we ever move on this I will consider both units, tho the "Wireless" is unavailable today.

[gregmchugh]

Originally Posted by Saldar

I'm sorry I missed your post. I would have welcomed a discussion about the Thornwave unit. The experts here already have the meter problem solved, I guess.

The Thornwave looks powerful. It does not appear to have an on/off switch (to avoid parasitic loss) or logging. I believe the "Wireless" does. If we ever move on this I will consider both units, tho the "Wireless" is unavailable today.

It appears that the Thornwave does have a way to turn it off and back on but it is through the app. I guess the question is whether or not it keeps track of current flow in the shunt and state of charge when it is off. It has a low (7 mA) parasitic draw in any case so leaving it on to monitor current would not be a big problem.