Planning Battery Upgrade--Need advice

[boondocking]

I stand corrected on the SOC, thanks.

[camaraderie]

Originally Posted by boondocking

It does tells me the voltage and amperage that the solar panels are producing.

Yes it does.

No it doesn't tell me present amps being used or the SOC or % of capacity while the batterys are being charged.

We agree.

It does tell me that stuff when the batterys are not being charged, when I de-activate the cutoff switch for the solar panels.

It does nothing of the sort

It gives me all the info I need while boondocking.

That's nice. Brooklyngirl might want reliable and comprehensive information that you think you're getting but aren't and can't possibly get from that meter. Once again...iff there are black wires attached to your batteries other than ONE from your meter with the "built in shunt"... you cannot possibly be monitoring your batteries for the things I listed.
*********

a real shunt connects to all house negatives on one side (two in this case...generally more) and ONE large negative from the other side of the shunt to the battery negative. The shunt is then connected to the monitor from a small wire to provide readings to be decoded by the monitors algorithms which include compensation for battery capacity battery specific peukerts constant and other factors which bear on capacity & time remaining such as current draw v. 20amp current draw rate. It also allows for adjusting battery capacity for monitoring as it ages. (i.e. if your 3 year old 100amp hour battery has lost 25% of capacity...you don't want to hasten its' demise by drawing it down to 50% of a 100 a/h battery...you now want to draw it down 50% of a 75 amp hour battery.
Without such adjustment you'd be taking that 3 year old battery down to 33% of capacity and killing is softly while thinking all was well.
Brooklyngirl...consider the Victron monitor as well as the Trimetric. Used all over the world and simple installation and cheaper. Both do the same things.

[boondocking]

I have been mis-informed. Thank you for setting things straight.

[brooklyncowgirl]

Thanks guys. What I'm looking for in a monitor is something that will let me know the state of charge of my batteries without having to access the batteries themselves. I would also like to be able to know how much power the appliances in the trailer are drawing so we can make good decisions about use (e.g. does it make sense to turn off the water pump at night) and when I finally get my solar panels what amount of energy the panels are putting into the battery.


It should also be idiot proof (there is such a thing as too much information), DIY installable by someone with basic wiring skills and not some huge thing that will take up the entire trailer.


My guess is that load testing is something we'd do once to see how much an appliance draws and then occasionally later on when we add a new toy to the system. I could see sense in buying a low end load tester and a battery monitor that does not test the current draw on the system if the two were considerably less expensive than the Trimetic or the Victron (which doesn't seem to be any less expensive than the Trimetic)


On the other hand you do get what you pay for. I just don't want to pay for something with a bunch of features I'll rarely or never use or even understand.

[camaraderie]

Originally Posted by brooklyncowgirl

Thanks guys. What I'm looking for in a monitor is something that will let me know the state of charge of my batteries without having to access the batteries themselves. I would also like to be able to know how much power the appliances in the trailer are drawing so we can make good decisions about use (e.g. does it make sense to turn off the water pump at night) and when I finally get my solar panels what amount of energy the panels are putting into the battery.


It should also be idiot proof (there is such a thing as too much information), DIY installable by someone with basic wiring skills and not some huge thing that will take up the entire trailer.

BCG...The Victron will do exactly what you want. Installation is easy and the simple directions require NO electrical knowledge or measurement. There is a short initial set up process with the meter where you enter your battery type & capacity etc.... after that you simply press one of two buttons on the monitor to cycle through the info you need.
It WILL show you:
Present state of charge i.e. 72%
Present amps being used or Present amps coming in to the battery...net.
Time remaining at present usage of batteries.
When you are 100% charged without waiting for surface charges or using load testers.
Since you can switch items on and off...you can see exactly what your TV or your fridge or computer uses.
Installation IS simple.
1.Take all black wires off your battery and instead put them on the "load end of the included Shunt.
2. Figure our someplace close to the batts to mount the shunt to. Now buy a standard black battery cable from the local auto zone that will reach from the battery to the shunt and connect it.
3. Take the included thin red wire and run it to the positive battery post from the shunt.
4. Take the included "telephone wire" cable and plug it into the shunt. Plug the othe end into the back of the monitor.
5. Complete wall mounting of the monitor and your done.

Victron Battery Monitors

The model 700 is good for multiple batteries configured as ONE bank as yours would be. The model 702 also lets you run wire and monitor voltage on the engine battery which is a bit of unnecessary expense in an RV I think.
Good luck with the decision making.

[Klipstr]

Excellent write up Cam. I was not aware of the Victron. Easier to wire than the Trimetric as they have the telephone port on the shunt! Nice touch.

Made in the Netherlands not the US but a minor point I think based on the apparent quality of the product. Has anyone used their other products? Might make sense for the cowgirl to go with these guys for her entire build maybe minus the panels...

[camaraderie]

Thanks Kelly... yes...they are a reliable engineering/design company and if you look closely you'll see they've made products for Xantrex label as well.
The other significant thing is price...the Trimetric does not include the shunt or the cable so you are over $200 going that route. Nothing wrong with the product at all...excellent...but a little more $$ and a bit more complicated to install.
"Additional parts you will need: Shunt, 4 wire cable from battery to meter, Short, large cable to go from shunt to battery"

Can't comment on the rest of their stuff from personal use...but the MPPT solar controllers let you hook in with your pc to adjust charging parameters for your specific brand/models factory recommendations... pretty cool.

[Tom48]

Originally Posted by brooklyncowgirl

We own a Tracer Air 252 trailer. The trailer came equipped with an Exide group 24 dual purpose marine battery. We've found that even without using lights (we're planning to upgrade to LED) that we had to run the generator every day when camping without shore power.

Since our plans are to do a lot of boondocking and camping in national parks and forests, etc. we want to upgrade our battery capacity and add a portable solar panel and use the generator for backup when solar fails.

The battery bracket is on the tongue behind the gas canisters. It consists of two pieces of L iron, the shorter of which is 26" set 9" apart welded onto the tongue from underneath (I'm a bit concerned about the strength)

The cheapest option would be to add another group 24 battery. I'd like to go with a true deep cycle battery instead of a dual purpose. Can I mix the two or would I have to buy two deep cycle batteries?

I'm also looking at the possibility of going with two 6 volt golf cart batteries. These should fit in the space we have and give us more power. Batteries Plus near me sells Duracell 6 volt batteries at a pretty good price. This would be more expensive but give us more battery for the buck.

At any rate, any advice would be greatly appreciated.

Before I even read the others let me start. Absolutely. Two batteries is a minimum. Two top line golf card batteries will fit in the same space as two grp 24s as long as you can fit boxes that are about three inches taller. That will give you the amperage of three 24s or more and much better batteries. Then get the solar. Renogy.com, Chino, CA or windynation.com Ventura, CA. Price is about the same. Wire it up laying on the ground if you must but get it on the room as soon as you can. You will never regret having it.

[Tom48]

Oh and while the panels are about the same inexpensive China stuff, the windy nation package that has their $50 30 amp pwm controller is a nice simple step. It has a display with battery state of charge displayed graphically. Not the same as the expensive monitor systems but more accurate than my factory display of state of charge. These days the only time our generator come on is when we want the a/C

[brooklyncowgirl]

Originally Posted by camaraderie

BCG...The Victron will do exactly what you want. Installation is easy and the simple directions require NO electrical knowledge or measurement. There is a short initial set up process with the meter where you enter your battery type & capacity etc.... after that you simply press one of two buttons on the monitor to cycle through the info you need.
It WILL show you:
Present state of charge i.e. 72%
Present amps being used or Present amps coming in to the battery...net.
Time remaining at present usage of batteries.
When you are 100% charged without waiting for surface charges or using load testers.
Since you can switch items on and off...you can see exactly what your TV or your fridge or computer uses.
Installation IS simple.
1.Take all black wires off your battery and instead put them on the "load end of the included Shunt.
2. Figure our someplace close to the batts to mount the shunt to. Now buy a standard black battery cable from the local auto zone that will reach from the battery to the shunt and connect it.
3. Take the included thin red wire and run it to the positive battery post from the shunt.
4. Take the included "telephone wire" cable and plug it into the shunt. Plug the othe end into the back of the monitor.
5. Complete wall mounting of the monitor and your done.

Victron Battery Monitors

The model 700 is good for multiple batteries configured as ONE bank as yours would be. The model 702 also lets you run wire and monitor voltage on the engine battery which is a bit of unnecessary expense in an RV I think.
Good luck with the decision making.

Thanks, I'll look into it. I did notice the thing about the shunt being included after I posted that the price was about the same. Sounds good.

[brooklyncowgirl]

Originally Posted by Tom48

Oh and while the panels are about the same inexpensive China stuff, the windy nation package that has their $50 30 amp pwm controller is a nice simple step. It has a display with battery state of charge displayed graphically. Not the same as the expensive monitor systems but more accurate than my factory display of state of charge. These days the only time our generator come on is when we want the a/C

Thanks Tom, I've been looking at Windynation or Renology for the panels. Whatever we buy it has to be expandable. I like the idea that the Windynation 100 & 200 watt kits come with a 30 amp controller included so we can add on panels as needed. They also give the same warrantee for their lightweight flexible monocrystaline panels as for their standard polycrystalline panels. As our dealer has informed us that drilling into our roof will void the warranty we're looking at a portable system at least for now. The light weight would be a plus but they have drawbacks; pricier, less durable and if mounted on the roof problems with heat build up.

Since money's an issue and our original battery is pretty new and we had concerns about the weight carrying capacity of the bracket, we decided to add a matching group 24 battery to double our amp hours. So far so good. We hope to get a year or two out of them. At that point we'll upgrade to 6 volt, have someone weld another support onto the bracket and will hopefully be in battery heaven.

[Blackhat6mike]

Originally Posted by Mountndream

Alot of people here use 2 6v Trojan t105's. they have 225 amp hours and if you look around can be had for relatively little more than standard 6 volts batteries. if you compare the amp hours, you get ALOT more with the T105s

Might want to try this site for high amp hr batteries. I've tried to argue with some that these batteries exist, but to no avail. Yes they do make a 175 amp hr AGM battery and even larger in 12vdc units.
Vmax Solar Batteries | Renogy Solar

[Blackhat6mike]

Originally Posted by boondocking

I could be wrong, but I have never heard of a Group 31 battery having a 200 ah rating, usually they are around 100-120 ah.

Vmax Solar Batteries | Renogy Solar

[boondocking]

There is no such thing as a Group 31 AGM rated at 200ah, the average AH rating for a Group 31 AGM is around 100 - 110 AH.
There are 200ah AGM, they are Group 921 and weigh about 120 lbs compared to a Group 31 at 70 lbs.

[camaraderie]

Ditto Boondocking...
....now show me a VMax group 31 with the specs you are challenging BlackhatMike.
The only one close is about twice the size of a G31. You are talking about & recommending things you don't understand and this misleads others. The 20 hour capacity of a group 3 deep cycle is between 105 & 115 amp hours. Some mfr's may exaggerate a little for marketing purposes...but none comes close to the numbers you are suggesting exist.
DIMENSIONS IN INCHES*: 12.9" 6.75" 9.27" LxWxH

[CharlieS3]

I have a pretty massive solar system on my Coachmen 380DS. For Batteries, I modified the battery holddowns to install 4 L16 Sun-Extender AGM batteries at 125 pounds each. I have added 6 of the Kyocera 140 Watt panels on the roof (2 more since the pic) giving me a whopping 840 Watts of power. This produces about 40 amps an hour in full sunlight. Per my Victron (highly recommended) we use about 125 amps a day. That includes making coffee in the morning, running the microwave at night, watching TV, and also running my CPAP. LED lights make a difference. For wet batteries, Trojans have a great reputation. Whether you go 6 volt in series or 12 in parallel, or some combination thereof, is not really relevant and will produce pretty much the same storage capacity either way. Just stuff the biggest batteries that you can into the available space and get the best you can afford. Deep Cycle of course.

While you can go portable, its a pretty big pain to setup every time. We look for sites that give minimal tree coverage, but you can't always avoid it. Its just the way it is. Larger capacity means I can go with less sunlight. If going solar, go with paralleling your panels rather than series connection, along with an MMPT controller. In series, if one panel gets shaded, all panels go down. In parallel, only the shade panel is lost. The MPPT controller will max your output. Less voltage may mean that you need bigger cables. Its all a tradeoff, but shading is almost always an issue and I went with the approach that minimizes that effect.

The Victron is a great unit. It tells you your current draw, lets you cut things on and off to see what is drawing heavily, lets you know your state of charge and your rate of re-charge. Lots of fun for a numbers oriented guy like me.

Good Luck with whatever you decide!

Charlie

[NorSnrub]

Wow Big. Wish I had room and money for something like that. BIG

[camaraderie]

Nice post Charlie...should be helpful to both big & small systems. Now for a couple of questions.
You are capable of 840 watts out of the panels which should average 200-225amp hours per day in a reasonable sunny place.
Your batteries are 740 amp hours at 12V...or 370 usable to 50%.
Your daily needs are described as 125 amp hours....so your batteries will give you 3 days in full darkness.
Why so much overkill in both batts and panels? Looks like you're ready for the grid to go down and the volcano to blow.

Glad you like your Victron... Trimetric gets good reviews here too but I'm a Victron fan.

[CharlieS3]

Good Questions. When I first designed and installed the system, I was pulling about 225 amps a day on average. Then I realized that I could knock off just under 100 amps a day by cutting off the inverter whenever I really didn't need it. The only downside is that I keep having to reset the microwave clock. I've also replaced most of my lighting with LED, reducing the load. The Victron really helps your general awareness of your load.

I also found that on overcast days, or in medium to heavy trees, I really didn't make much power. Since we prefer national and state parks, avoiding commercial parks whenever possible, the big system just lets us get more time. Plus, I don't run down the system as low as I might otherwise, saving battery longevity. I can really be pretty much as piggish as I want. While I also have a 7.5K genset, I almost never use it.

Adding the last two panels was really a no-brainer. I had the space, and other than some mounts, the two panels, and a little wire there was minimal marginal cost, relatively speaking, to increasing my output by 50%.

I'll admit that I like to tinker, often just because I can. I've had this thing for 3 years, but have replaced the TVs, the radio, the satellite antenna (so I get HD), the water pump (better pressure), fixed most everything that bugged me, the lighting with LEDs, added the solar, redone the lines to the LP tank to resolve a leak, replaced the camera system with a 3 camera color, added a CB radio (I really wonder why I did that), replaced the useless fog lamps with driving lamps, heck that's just what I remember. I drive my wife a bit crazy, not that its a long drive.

Next, I'm adding an installed brake system to the wrangler toad and adding the blue ox steering stabilization. I'm thinking about the comfort ride control valves for the airbags, but need a bit more research.

No, I'm not retired. I run four different businesses and volunteer as a paramedic 14 hours a week. I just like to tinker when I can.

So really, I made it that big just because I wanted it that way.

[camaraderie]

Thanks for the explanation... makes good sense. Sounds like it's all relaxing for you. Some people like to fish...others like to play with their tool bag...others like to watch and give advice. Heheh.