REV 24 house batteries

[Delco Bobby]

Originally Posted by PanAmMan

I still have not found any real world alternator Idle charging Amp numbers anywhere for the Promaster based REV 24's...

Anyone with a good battery charge state meter, which everyone who boondocks should have, should have that info available...

Any suggestions on where or which thread to look folks?

-PanAmMan

Correct me if I am wrong. It seems you want to run your engine while parked for long periods to charge your batteries.

That will burn up alot more gas than your generator and will be harmful to your engine.

[PanAmMan]

Originally Posted by Delco Bobby

Correct me if I am wrong. It seems you want to run your engine while parked for long periods to charge your batteries.

That will burn up alot more gas than your generator and will be harmful to your engine.

Engine harm is a real issue on private vehicles used in commercial applications where very long idle times are common. Commercial van bodies used for ambulances and refrigerated goods must meet such requirements. Especially those branded as Professional grade like the Promaster.

Closed Loop Fuel injection, oversized radiators, and electric fans are used to overcome heat buildup problems common in private vehicles not accustomed to loitering about on 24 hr shifts.

That said I have no intention of idling my engine for hours on end!

But it is an important need given the REV 24's high overnight parasitic loads which can take more than 50% from the battery even when running the fridge on propane, as so many have reported.

That combination of small battery capacity and high overnight draw makes it hard to make it from 8pm to 10am on the REV 24s batteries alone!

I tend to be a polite neighbor so running the REV 24's mind numbing Genset before 10am to minimize battery damage is a social no no!

My goal is simple:

- Run the vehicle engine for 40 min to hold my batteries over at > 50% charge while I get my coffee and breakfast made without reducing the life of my batteries or making myself the camp pariah.

- Add at least one more 100Ah battery and high idle to encourage the alternator to put 80 to 100Ah back into the 3 batteries in that 40 min.

- Add 500W or more of solar panels to keep the batteries charged in peaceful bliss during the day.

- Run the mind numbing Genset when I need the AC while boondocking or tailgating with the wildbunch.

None of these incremental changes are expensive. Initially, I will just idle the engine longer to make up for low Idle charge rates until I install the high idle kit.

Adding solar is more for my own sanity while boondocking since I did not drive into the wilderness to hear my own or anybody else's mind numbing Genset ;-)

After all some of the best places to camp don't have AC plugs or allow Genset's at any time during the day!

-PanAmMan

[FFred]

"Add at least one more 100Ah battery and high idle to encourage the alternator to put 80 to 100Ah back into the 3 batteries in that 40 min."

Far better to install a marine style 3-4 stage Voltage regulator.

The car brained V regulator does not give a very raoid charge , even to well down batts.

Here is ONE brand , there are many others,
Search Results

Balmar | Marine Charging Systems | Battery Monitors | Multi-Stage ...

Balmar | Marine Charging Systems | Battery Monitors | Multi-Stage Voltage Regulators | High Power Alternators | Serpentine Pulley Conversions

Marine Charging Systems | Battery Monitors | Multi-Stage Voltage Regulators | High Power Alternators | Serpentine Pulley Conversions.‎Alternators · ‎Multi-Stage Regulators · ‎Products · ‎6-Series Alternators

Balmar Voltage Regulation Technology | Balmar

Balmar Voltage Regulation Technology | Balmar

Without proper voltage regulation, battery charging can be a slow process, or even worse, an ideal recipe for early battery failure. ... Balmar’s patented Max Charge and ARS-5 Voltage Regulators

[steve32409]

So glad PanAmMan got on here - because I have a 1st. year model Rev , only one battery ( always had a battery consumption problem ) but never thought about it to much . Now will be adding 2 new 100ah and maybe a 3rd and I am learning much more also about idle charging and my ( kind of loud ) generator charging also . thanks all

[bclemens]

"But it is an important need given the REV 24's high overnight parasitic loads which can take more than 50% from the battery even when running the fridge on propane, as so many have reported. That combination of small battery capacity and high overnight draw makes it hard to make it from 8pm to 10am on the REV 24s batteries alone!"

Be careful with believing what you read on the internet. The first ones went out with only a single group 27 battery. next year it went to (2) group 31's. Also a bad battery will never make it through the night. How many people are assuming the battery just can't handle it, when it was run down to 8v or lower at the dealership time and time again, reducing the capacity. Unless they have run a load test, I find it hard to believe a dual AGM set up would be an issue. I have camped many a night like that with no issues, even with some furnace use. (and not the efficient Truma-Combi that is in there now, a regular suburban furnace)

[PanAmMan]

Everyone's mileage will vary especially since some are starting with a half full tank.

Due in no small part to

1) Poor RV storage habits
2) Charge controllers that do not reliably maintain or protect the house batteries from abuse. Or maintain their charge above 50% when using the RV away from an overnight utility connection.

The PD controllers look like a big improvement for those that keep their RV plugged in when stored. But the lack of a simple to follow and perform RV storage checklist and basic % remaining battery meter makes it hard for the average RVer to reliably maintain their house batteries above the optimal 50% discharge or 80% storage levels.

Your work to get the PD charger added as standard equipment is admirable and appreciated. But that alone is less than half the battery management problem for the average RVer.

Unfortunately, the other half requires the RVer to follow battery manufacturer's recommendations which are published as % of charge amperage even though most RVs are shipped without such a display from the factory.

That would explain most of the confusion and poor results RV customers are getting including those caused by dealers that know better but don't make the effort to keep the RV's batteries in like new condition. Some do, some don't.

It also dooms many to replace their batteries much more frequently than if they knew when and how to change their behavior to minimize ordinary wear & unnecessary damage. Much of which can be solved by a true % capacity display.

We see this all the time in the marine sailing market where boon-docking without access to AC utilities for a few days at a time and alternator charging are much more common.

Many vendors are now saying that their focus is on Lithium to provide a modern more automatic solutions for future new sale RVs. And their probably right if they work with a very good lithium battery integrator.

A well designed low-cost Lithium pack can solve 90% of the deep cycle problems at twice the purchase price but 2 to 3 times the longevity. But lithium deep cell replacements that meet this capability won't be built using cheap Chinese LiPo cells used in consumer RC cars and UAVs.

So a simple, low cost, deep cycle battery capacity meter seems like a better solution for at least the next few years until the lithium packs come down.

Such meters exist but are typically much more expensive and complicated than what the average RVer needs or will actually use.




-PanAmMan

[bclemens]

We actually run a true voltage meter in our multiplex units...we just haven't get them all converted over. Another 12 months.

[PanAmMan]

All meters are voltage, but they can get amps from an amp shunt in series with the battery(s).

[bclemens]

Sorry, thought you were referring to the standard "full, half, empty" gauges.

[PanAmMan]

Some of these volt based, amp estimating, % capacity meters can be accurate enough but only when you do at least 50% run-down discharge just before each trip.

That's the only way they can recalibrate their amp capacity algorithm to accurately reflect the capacity-robbing damage that may have occurred during the last storage cycle.

Those cycles are not needed during most rV trips unless they last multiple months and or the RV'r NEVER discharges their battery bank below 60% or so.

As a manufacturer, the above is relatively easy for you to test especially if you have a 3 or 4 of sets of batteries that have different levels of remaining capacity laying around on their way for recycling ;-)

Just switch the Capacity meter between the battery banks and then do a 50% calibration run down followed by three 70% capacity accuracy run downs while the bank is also attached to a professional or commercial true Volt-Amp based battery condition monitor.

This will show you the calibrated and uncalibrated accuracy of the amp estimating capacity meters vs a top of the line capacity meter. I think you will be both alarmed with the uncalibrated accuracy and please with the post 50% run down accuracy of even the lowest cost capacity meters.

To save time and cost you can run multiple meters on each bank run to save time. We used to run 10 or more at a time.

By the way the Amp estimating capacity remaining algorithms that work reliably with a 50% run down calibration are not difficult to implement on most Volt only multifunction displays. I have seen it done with less than 50 lines of "C" code or 500 bytes of tight machine code in a PIC processor.

I your really looking for an industry leading solution for your current and existing retrofit RV lines PM me.

[steve32409]

while measuring my battery compartment yesterday I found that my ground cable on my only battery was so loose that I could finger tighten it several turns before I used a wrench ? - don't know how that could happen but now know why I had problems on our last trip . Used the frig for a full 12hr last night and this morning only had one light out of four showing on the in house test and the steps came down also - but slowly.

[PanAmMan]

Congrats on locating your problem, Steve...

Rattling battery cables play havoc on the both the charging and discharge amp capacity of the battery bank.

I use high-quality Nyloc nuts to prevent that ;-)

That and I hate adding yet another item to my already too long pretrip checklist ;-)

You would think that using std nuts, attached to big cables that get bounced around a lot, on low maintenance batteries that you don't have to check so ofter kind of defeats the purpose of not needing to open the battery box ;-)

Shortening my pre trip checklist is a passion of mine. But it will probably never match the very short pre-boondocking checklist of my pinzgauer.

- Charge the two 12V Optima deep cycle batteries after going flat due to being buried in a snow bank all winter long.

- Chk Oil Level & Tire Pressure while Filling gas tank!
- Go safely where no sane Jeepster will follow!

I will probably never own another RV that I will trust while boondocking so completely.

[steve32409]

ready for the road again / 20,000 mi last year . New agm 200 ah battery , new high quality battery charger if I need it ( https://www.vmaxtanks.com/BC1220A-12...er-_p_160.html ) , and wired a accessories / usb port direct to battery to inside of coach to easily see battery shape.