New RV'r - Batts + Chargers + Inverters = clueless

[tsweez]

First, I am a newbie in every sense of the word. New RV'r and new to the forum. So if you see any flaws in what I'm trying to do, please let me know.

I recently purchased my first RV. A late model, 91 Mallard Sprinter. Eventually I'd like to have it setup with solar, an inverter, and enough batteries to hold me for several days. But for now, I have a generator and a dead 12v coach battery in the engine compartment.

I thought that rather than replace the existing 12v, I'd build a vented battery enclosure in the basement area adjacent to the generator. The idea is to start with two 6 volt Trojan T105's or similar and have enough room to add two more once my battery needs become a bit clearer.

My first challenge is to better understand what I need to do as it relates to the simple relocation of the exiting battery to the new location. I know the existing coach battery charges via the generator and the engine via some form of isolator, but I'm clueless what I need to do to simply replicate these functions once I move to the new coach battery location. Any feedback is most appreciated.

For reference, the plan is to add a 1500w PSW inverter, battery charger, and transfer switch (All GoPower Products). The goal is to:

- Draw and charge from shore power when plugged in
- Draw and charge from gen when running
- Charge when engine is running
- And eventually, charge from solar

But all that comes once I simply setup the new battery config.

Thanks again, and kudos to all of you for having such a great community here. The information has been absolutely invaluable.

Thanks,

Tim

[tsweez]

Hey MexicoWanderer! For reference, the Mallard is on a Ford Chassis.

Best,

Tim

MEXICOWANDERER wrote:
What chassis does the '91 mallard use? Ford? Chevy?

Keep in mind that 2 pairs of golf car batteries can gulp down 160 amps of charging without a burp. Wouldn't it be nice to have that kind of amperage recharging the battery bank for that hour?

[pianotuna]

Hi,

Don't forget that charging batteries is a frog on a log situation. The closer they get to 100% the slower the acceptance rate. The three brands of converter mentioned (Iota, PD and Powermax) are all going to meet your needs.

I'd not install one that won't work on a 15 amp circuit, for there are times when that is all that may be available.

[mena661]

A 90 amp IOTA requires a 20 amp circuit. So does the 75 I think. The Powermax Boondocker 100 amp only requires a 15 amp circuit.

[MEXICOWANDERER]

What chassis does the '91 mallard use? Ford? Chevy?

Keep in mind that 2 pairs of golf car batteries can gulp down 160 amps of charging without a burp. Wouldn't it be nice to have that kind of amperage recharging the battery bank for that hour?

[tsweez]

I will do just that Jim. Thanks a million!

HiTech wrote:
That's really good news. Most places will load test to confirm the service worked. Run a heater or the AC (depending on local temps) for a few hours and ensure it holds up. Driveway camping works out a lot of bugs.

Jim

[tsweez]

From what I tell, at least at a glance, the IOTA is indeed a preferred solution in addition to the Progressive Dynamics controllers with their Charge Wizard. There appears to also be a good amount of information regarding the upgrade of my existing solution to both the IOTA and PD products. I'm looking at that now.

Your feedback here is most appreciated.

Tim

smkettner wrote:
Go Power converter might be excellent. Just have not read how well they do in various conditions.

Only the 6345 has a separate charging circuit that is now obsolete.

IOTA is a proven solid reliable converter and will charge your batteries great. The IQ controller module changes the converter from a single stage (fixed voltage) converter to a three stage converter. With low battery it steps up voltage for a fast charge and then in two steps drops the voltage for normal use. All multistage converters work this way. I assume Go Power is similar... just have not read much on them.

[tsweez]

Thanks Kiwi_too, thats a good suggestion.

From what I understand, Trojan recommends about 10 to 13% of the 20 hour Ah for longer charges and up to 20% when faster charging is required. As the batts would be about 450 Ah, it looks like the range would be between 45 on the low end (which I have now) and 90 amps on the high end. But yes, apparently with 100 I run the risk of damaging by batts.

I think reaching out to Randy is prudent anyway, so I do thank you for the reference/recommendation.

As for the generator vs. engine charging the batts and which is most economical, I hadn't thought of that. That is definitely worth testing. Ideally, what I'm trying to do here is to have the batts charge either via the engine, shore, solar, etc. And the inverter with a transfer switch so the system acts like a battery backup in the absence of shore power or gen. At least for 110 service.

Best,

Tim

Kiwi_too wrote:
If I were you, I'd list what my batteries are, size of wiring, distance of run and if you are willing to upgrade wiring. Then call Randy at Best Converter. 100 amps may be over kill.

I might disagree with the idea that the generator is a better option than an alternator. This depends on your alternator size and charge line size. It might even be cheaper to run the engine alternator than a generator. Check out the fuel consumption, per hour, on your genny. Genny's are convenient but not always efficient power converters, especially just to plug into the rig for running a converter/charger. You could use a 3 stage battery charger straight from genny to batts.

Now if you are running the genny in the am, while using the micro to cook or the electric coffee maker, than you can charge batts at the same time then combining the two requires the genny. Just charging batts does not.

[HiTech]

That's really good news. Most places will load test to confirm the service worked. Run a heater or the AC (depending on local temps) for a few hours and ensure it holds up. Driveway camping works out a lot of bugs.

Jim

[time2roll]

Go Power converter might be excellent. Just have not read how well they do in various conditions.

Only the 6345 has a separate charging circuit that is now obsolete.

IOTA is a proven solid reliable converter and will charge your batteries great. The IQ controller module changes the converter from a single stage (fixed voltage) converter to a three stage converter. With low battery it steps up voltage for a fast charge and then in two steps drops the voltage for normal use. All multistage converters work this way. I assume Go Power is similar... just have not read much on them.

[tsweez]

Thanks Jim!

Fortunately the generator was just serviced and everything checks out a-okay. But alas, I will run a load on it for a number of hours to see for myself how it holds up.

And thanks for the battery tip. I'll look it up to be sure, but I'm glad you promoted me to do it the right way!

Best,

Tim

HiTech wrote:
If you have alternator charging the chassis battery, and you get anything charging the house batteries how you like, this will let either charging system charge the alternate battery quite nicely.

Unfortunately if your genset only has 13.5 hours on it, it probably has not been properly maintained. Time to change oil and filters and load test it for a number of hours.

Look it up but if I remember right the right procedure on a battery that is very low is fill with distilled water to just cover the plates, fully charge, then top off (don't let the fluid touch the bottom of the fill rings). Then overcharge to reverse what sulphation you can and stir around the acid and new water. A drive is good for stirring up the electrolyte as well

It is worth trying out that existing battery and seeing what it has left after a recovery attempt.

Jim

[AllegroD]

If I were you, I'd list what my batteries are, size of wiring, distance of run and if you are willing to upgrade wiring. Then call Randy at Best Converter. 100 amps may be over kill.

I might disagree with the idea that the generator is a better option than an alternator. This depends on your alternator size and charge line size. It might even be cheaper to run the engine alternator than a generator. Check out the fuel consumption, per hour, on your genny. Genny's are convenient but not always efficient power converters, especially just to plug into the rig for running a converter/charger. You could use a 3 stage battery charger straight from genny to batts.

Now if you are running the genny in the am, while using the micro to cook or the electric coffee maker, than you can charge batts at the same time then combining the two requires the genny. Just charging batts does not.

[HiTech]

If you have alternator charging the chassis battery, and you get anything charging the house batteries how you like, this will let either charging system charge the alternate battery quite nicely.

Unfortunately if your genset only has 13.5 hours on it, it probably has not been properly maintained. Time to change oil and filters and load test it for a number of hours.

Look it up but if I remember right the right procedure on a battery that is very low is fill with distilled water to just cover the plates, fully charge, then top off (don't let the fluid touch the bottom of the fill rings). Then overcharge to reverse what sulphation you can and stir around the acid and new water. A drive is good for stirring up the electrolyte as well

It is worth trying out that existing battery and seeing what it has left after a recovery attempt.

Jim

[tsweez]

Jim,

You are right on both actually. For shorter weekend trips with my daughter, I want to be prepared to get by a couple of days dry camping with increased usage that includes more xbox, TV, etc. When I'm on my own, these trips could be more like a week at a time. But my power requirements should drop as I'm not a big TV or Xbox guy, but I do need my laptop.

I do plan on installing a solar solution to help me stay charged on my week long dry camping trips. Before I layer on that investment, I want to better understand my power usage. But regardless, I did plan on using the gen for the Microwave and A/C if a simple fan doesn't cut it. I should have also mentioned, that I do have a CPAP (no humidifier heater) that fits into this equation as well. So there will be a small load throughout the night.

As for the battery, I do not have one laying around. The existing battery does have a small charge, and I did notice the cells appear to be either low, or dry. I'll try adding some distilled water and picking up a hydrometer later today.

I like the idea of the driveway camping test. Sounds like a great idea. I suppose I could get a 12v adapter for my laptop and just connect via WiFi to the house. It's going to be tough to get any feeling for power usage without the inverter though. But still, I foresee more of this as the configuration matures 🙂

Best,

Tim

HiTech wrote:
Tsweez do you have any idea what your camping style will be? How long dry camping at a time? From the mods you are talking about it sounds like either weekend dry camping with pretty heavy battery usage, or longer trips trying to minimize genset time.

Also just to get going do you have any old 12v battery you can toss in to replace the dead one, and/or are you sure the coach battery is unrecoverable? I ask because sometimes trying things out adjusts your requirements vs. what you believe them to be on paper. Driveway camping doing some tests could be handy to try some systems out.

Jim

[tsweez]

This is terrific information. I was planning on replacing with a GoPower 45 amp charger but looks like I need to step it up. For reference, this is what I was planning on purchasing and they do have both 75 and 100 amp models.

http://gpelectric.com/products/smart-battery-chargers

Curious about a few of things if you have another moment:

- Am I correct in assuming that the DLS itself is the converter and the IQ controller is the charger?
- Any thoughts as to how the GoPower might compare to the DLS or am I really in apples/oranges territory?
- The GoPower unit notes it's designed to charge 1 battery bank. Pardon my ignorance, but are 4 batteries wired series/parallel for a total of 12v still considered one bank?

Thanks again. That was great information that likely prevented me from making a configuration mistake.

Best,

Tim

smkettner wrote:

tsweez wrote:
Okay, so I found the charger under my fridge. It's a Magnetek 6300A Model 6345 which I assume is far from what I need.

4x GC2 I recommend a 75 or 90 amp IOTA with built in IQ controller.

http://www.bestconverter.com/-DLS-Series-12-Volt_c_144.html

If you must save money you could get a 45a now and parallel another 45a later next year. Charging is about the same, just takes longer with less amps. Might need the external IQ controller to go parallel.

6345 is only about 6 amps charging 😞

[tsweez]

Hi Almot,

The 6345 has a label which identifies the unit as both a Power Converter and Batter Charger. I assume this is what needs to be replaced anyway, but I think you are correct that there is another piece called an isolator which helps facilitate the charging from the engine to the battery. I think I still need a new charger, but also have to figure out how this isolator functions. But frankly, I can be talked down from the idea of the engine charging the battery as it does now. I just thought it was prudent to do this if possible.

As for requiring a power source for topping the batteries on longer trips without shore power. Yes, I have a gen which works great. In fact, in only had 13.5 hours on it when I purchased the Mallard. I had planned on using this for heavier loads like the AC and Microwave. Before I go the solar route, I wanted to have the batteries in place with a battery monitor so I can better understand my power usage as to scale a solar solution appropriately. As you pointed out, I hear too many stories about underpowered systems and I didn't want to make that mistake.

Best,

Tim

Almot wrote:

tsweez wrote:
Okay, so I found the charger under my fridge. It's a Magnetek 6300A Model 6345 which I assume is far from what I need.

This thing is called converter I think, but what is it that you need? If it's boondocking, then converter model doesn't matter. Converter will be charging the batteries from shore power - when you don't really need batteries. Motorhome engine alternator - probably a separate device from that Magnetec - will be charging them as long as the engine is running, which is usually not long.

For a weekend it doesn't matter, you will charge them at home again.

To survive more than a few days without shore power, you need not just enough batteries but also a power source, and the engine is not a good source. Then you either have to run a generator, or a proper solar system - which would include a charger/controller, or both generator and solar. Some people with solar run generator occasionally. Most people with solar use generators a lot, because their solar is not adequate to their needs (needs too high or solar too small and/or not done properly). Microwave alone will cost you half of your daily energy.