Any innovative solutions for adding more batteries?

[smoline]

My 2014 CS Adventurous has the standard configuration of two 6-volt deep cycle batteries under the hood to supply the coach power, a 1250 watt inverter, and (optional) solar panels. We boondock a lot; almost exclusively. We'd very much like to add more battery power to our rig. Does anyone know a way or have a proven method to do this? I would even sacrifice the spaced used by the generator to replace it with a "battery box" of some kind.

Thanks,

Steve

[gerrym51]

pianotuna-you need more e-trek info




e-trek infolinky

[pianotuna]

Hi Davydd,

I think Alvars recharge numbers are pretty high, particularly the 300 amps per hour from the extra alternator. A V-10 would be a better choice than the Sprinter diesel engine for idle based recharging. I can, in a pinch, use the v-10 with the oem alternator (130 amps) to recharge at up to 70 amps (perhaps higher--but my meter doesn't read above that number). Someday I'll have to try it while idling. So far I have only used it while driving at highway speeds.

I love solar recharging but again their numbers are pretty much "summer time only". The flexible panels seem to have "come of age" now with excellent output per square foot.

Espar heating is a magnificent idea. Do they plan to use it for space heating too?

The outback inverter is one of the ones I was considering--but I wanted hybrid technology. I'm often where I only have 15 amps to play with, so being able to draw from shore power and the battery bank at the same time is useful to me.

Have they considered going to 24 volts DC?

We live in exciting times for new technology and RV's. In 1990 a 5000 watt grid tied inverter was about $50,000.00.

It sure is going to be one nice Class B when they finish it off.

[Davydd]

For what it is worth, I previously posted Advanced RV's going off-grid plans for electrical management earlier in this thread. This is my detailed plan that dovetails with what Advanced RV is doing.

Advancing Alvar's Revised Electrical Requirements

Short description solution - 600 ah lithium-ion battery bank, 450 watts solar, second alternator, 2800 watt inverter/charger, diesel powered hot water and heat, and no propane or Onan generator. This is something I could not cob together on my own and know over a year of development at Advanced RV has gone into making it happen.

More details of similar efforts are here:

Mar Azul DIY Adventures with Lithium-ion Batteries for Marine Applications

Technomadia Lithium Ion Batteries for RVs

[pianotuna]

Hi,

I think I have found the battery of my dreams! 503 amp-hours at the 100 hour rate. 357 amp-hours at the 20 hour rate.

Flooded $1100.00

If AGM then 260 amp-hours @ 20 hours $683.00

Two of these would be quite magnificent.

[pianotuna]

Hi smoline,

With 230 watts of solar I would not increase the battery bank to more than 400 amp-hours, or I would do "bank switching". Two banks of 300 each would allow equalization on each using solar. Lifeline uses the word "conditioning" instead of equalizing.

For heavy inverter use 12 volt jars do have an "edge". I'd consider using two 8 D AGM's if you can find room for a rack to be welded under the Sprinter.

Best bang for the buck still remains flooded cell. Watering when mounted under the RV becomes an issue. There are watering kits available but they cost nearly as much as a battery. Since that is so, you are now in the "price range" of AGM.

If you have deep pockets consider the Edison battery because depth of discharge can be 80% on a regular basis. I don't know if they need equalization or not. There is a firm in Florida which makes them.

230 watts is going to harvest about 1 kwh per day (or 80 amp hours) in June. Parasitic loads will "dine" on about 30 amp-hours. That leaves 50 amp-hours for all other uses.

My coffee pot uses about 5 amp-hours per brew. The toaster about 9 amp hours. The microwave consumes 2 amp-hours per minute. The induction cooker about 1.5 amp-hours per minute of use. A breakfast of bacon, eggs, toast and coffee consumes about 30 amp-hours. So with a harvest of 50 amp-hours net, one can do one meal electrically per day

My guess is that with only 230 watts of solar you won't be able to use the inverter much at all without dipping into the battery reserves.

I chose to have an extra large battery bank (with bank switching) and when I was part time this worked well for trips up to a week. In the time between trips the solar would return the bank to full capacity. Now that I'm full time I have to run the generator, or find a plug in.

I don't attempt to fully recharge with the generator. I use it for opportunity charging when I'm running an electric heater to warm up the bedroom, or using the electrical appliances in the kitchen. I've used just 53 liters of propane since Feb, 2014. (filled up the last week of September). Almost all of that was for running the fridge.

Once it became too cool at night (5 c) I'd run the generator for a total of about one hour. It does have remote start (and stop) so that represents three 20 minute run times.

The solar system works well and has great low light capabilities--but I need to either add to it (say 1200 watts more), or start over and build for 1500 watts.

I'm considering putting solar panels on to replace the awning. There may be a width issue.

My house battery banks are getting old in the teeth--four of the batteries are nine years young, and three are now five years old. Because I'm in a class C, I chose to use marine batteries for all places--so my starter battery is also marine. I'll keep on using them until I have a failure. Because of the cold, LI is probably not an option for me, so I have to decide between trolling batteries or AGM.

I don't expect to replace the batteries again for the remainder of the time I wish to RV.

My big purchase this year was a hybrid inverter. BFL13 has found a 2000 watt hybrid that might suit you as an upgrade.

[smoline]

pianotuna wrote:
Hi smoline,

Exactly what do you want to run with the larger battery bank? Is it to extend boondocking in "grey day" situations?

Will you be upgrading the inverter to a larger size?

How many watts of solar do you have? Is it possible to beef up the solar by adding more panels?

LI is quite expensive and at least for RV's is the "new kid on the block". You may want to look at Edison batteries instead, which are a mature technology.

LI appears to not do well in cold temperatures. Not only can you not charge them, you can't draw from them either.

Don:
1. More days of autonomy. Ability to power items that have higher load demand (e.g., coffee pot, toaster, etc.)
2. Perhaps. Let's see if the current 1250W inverter will suffice.
3. 230W of solar. No room left on the Sprinter rooftop.
4. Agree with both the LI and NiFe assessments
Thanks,
Steve

[gerrym51]

Pianotuna-you rv at minus- 34F. amazing - I try to never be less than 50f.


however i doubt the OP will be building heat controlled battery boxes.

[pianotuna]

Hi Davydd,

I have not seen a rating for lower than 20 F on LI. I RV at -34 F. LI are not suited to that sort of temperature. If I'm wrong that's great.

Davydd wrote:

pianotuna wrote:

LI appears to not do well in cold temperatures. Not only can you not charge them, you can't draw from them either.

Wrong. They do better in cold weather than lead-acid batteries. What you cannot do is bulk charge them in below freezing weather. Solution. Insulated heated battery box. Besides, few Bs are designed for use in sustained over 24 hours below freezing temperatures and I doubt many use their Bs in sustained below freezing temperatures.

[Davydd]

pianotuna wrote:

LI appears to not do well in cold temperatures. Not only can you not charge them, you can't draw from them either.

Wrong. They do better in cold weather than lead-acid batteries. What you cannot do is bulk charge them in below freezing weather. Solution. Insulated heated battery box. Besides, few Bs are designed for use in sustained over 24 hours below freezing temperatures and I doubt many use their Bs in sustained below freezing temperatures.

[pianotuna]

Hi smoline,

Exactly what do you want to run with the larger battery bank? Is it to extend boondocking in "grey day" situations?

Will you be upgrading the inverter to a larger size?

How many watts of solar do you have? Is it possible to beef up the solar by adding more panels?

LI is quite expensive and at least for RV's is the "new kid on the block". You may want to look at Edison batteries instead, which are a mature technology.

LI appears to not do well in cold temperatures. Not only can you not charge them, you can't draw from them either.

[Davydd]

Now that you have read the combined wisdom of all of us, have you given any thought of just asking Roadtrek? 😉

[gerrym51]

Steve,

2 things.

1. you might consult pianotuna on this board(i think that's his moniker)-i've found that he's the most knowledgeable on this board about batteries and solar-he'runs practically everything with this.

2. even if you get 2 more batteries-your other charging methods won't be changing. the solar you have helps of course but you'll still be using the standard roadtrek alternator-you' wont have the 'engine generator super alternator' whatever.

your only bulk charging options will be plug in,generator,or standard
alternator.

if you won't(or can't) use the generator what do you have left.

you can plug in before you leave on a trip and be full. driving will help-but if you wan't to do extensive boondocking i see no option not to use the generator.

[smoline]

gerrym51 wrote:

I would trade in your CS for a new CS with full E-trek or 1/2 e-trek package. that would solve your battery/inverter problem and get rid of your onan loudness problem. you might be able to do it without taking a large financial bath.
gerry

Gerry:

I examined doing exactly that. And even now with the 2015 models out, trading in my 2014 is still a crazy expensive proposition, incurring an enormous loss. I continue to look around for a good deal, but so far no luck. Seems like finding a way to add more batteries is less expensive.

Steve

[smoline]

Admin wrote:
Back on topic please

Admin
RV.net

THANK YOU!!

Signed,

A grateful OP

[smoline]

Arizona Kid wrote:
To the OP have you installed the Onan resonator, it really does help quiet the gen-set.

I have not (yet). Had one on my Chevy Roadtrek with a gasoline generator. The propane generator in the CS Adventurous seems a "little" quieter. If the Onan resonator will help quiet it down, I'm all for it. Thanks.