House-Chassis Battery Arrangement

[rpasetto]

I think that there a lot of Monacos out there of the '04 to '07 vintage which have a double set of house batteries.  That is there are two sets of four golf-cart type 6v batteries in a series parallel set up.   One of the four 6v-golf-cart  setups is in a tray in the big, (standard) battery compartment and the other tray contains the chassis batteries.  The second set of four is in a smaller compartment, aft of the mani battery compartment with an identical set of  four 6v-golf-cart  batts.

(1) The first question which came to my mind is:  why did they do it that way?  It would seem that putting the chassis batteries in the aft compartment and putting all eight of the  four 6v-golf-cart batteries in the big compartment would have made more sense.  It might have even shortened some of the Chassis Battery cables going to the starter.

(2) Secondly, with the big compartment dedicated to House batteries, why have eight of the golf cart types?  Could one of the trays be eliminated, installing four bigger 6v batteries, L16's for example.  That second option would reduce the number of cables/connections, although I do not know if there are larger batteries available which would match the capacity of the two golfcart batteries being replaced.

Has anyone done, or considered doing (1) or (2)?  Are  reasons not to do either?  I'd appreciate advice.

 

.. Rick P  05 Sig

[K9 Exec]

Hi Rick,

I am new to this forum, just joined a week or so ago but I feel obligated to reply. I am replacing my coach batts (4) 6V golf cart batts which are only 2.5/3 years old with But shot already, with a new technology called Battleborn Lithuim Ion Phosphate  100ah. They are not cheap but will last us 10+ years vs replacing these 3-4 times in the same period, with a built in battery management system to prevent shorts and also has a 10 yr warranty. This type of batt can be discharged to 10% vs only 50% without damaging and shortening the overall life. The Battleborns have  3,000-5,000 charge/discharge cycles vs the standard agm/flooded batts. I will be installing a total of 6 in a parallel configuration, but they are only 30lbs~each, roughly half the weight of the 6v batts.
 

I am also adding a 2400watt solar array and Magnum Energy hybrid inverter as well. If you would like to DM me or ask questions, I would be glad to reply! This is my wheelhouse. 
 

Thanks,

Nic

Edited June 5, 2020 by K9 Exec
Addition info

[trailmug]

Maybe height, since group 31s are 2+ inches taller than GC2s? GC2s are a little bit of a squeeze in both of those upper shelves. Also I believe the second set was sold as a package with the residential refrigerator, so it perhaps helped to standardize the cable lengths, etc, to add the aft set if specified. Within the same battery tech, it seems batteries of a similar physical volume have a similar capacity. Our house set lasted 4 years, and I just replaced it with another round of GC2s, because $720 for 860Ah was vastly more economical than anything else I could think of. It is a valid point, however, that with lead batteries, only about half of that capacity is actually usable if you want to avoid prematurely aging the batteries.. and if you want to be able to start the genset. 🙂 I think the latter would be helped by a larger gauge cable, though.. maybe 1/0 vs 2ga. On float charge the generator terminals drop to 9V during cranking, and the computer will abort start if it sags to 6V. As soon as I can figure out where the other end is, I will upsize it and post results.

Has anybody done anything with venting the battery bays? I would think with flooded or even VRLA, you would end up with H2S in the bay eating the steel.. which maybe is why those slide trays have aged so poorly.

Edited June 5, 2020 by trailmug

[Pduggs]

I’ve seen the configuration in higher end Monacos where all eight House batteries are in the big battery compartment and the two chassis batteries in aft compartment. 

My plan is to switch house to lithium rather than add four more flooded batteries, but my flooded house batteries are only 1.5 years old. 

[Chargerman]

My coach came with the 8 house batteries with 4 of them being in the rear compartment. The reason that the second set of 4 are in the rear compartment is because they were an option. When not ordered this allowed this rear compartment to be used for storage. The extra 4 batteries were provided when a residential fridge was chosen as an option. From my experience with my setup is that they last a lot longer than 4 years if maintained and charged properly. Regarding the longevity of the steel trays I coated mine with 2 coats of POR-15 and this has made them stay like new for years. A key to this is also setting the charge rates properly. When I got the coach the settings were too high and it boiled the batteries when charging. With the correct settings this is eliminated 

[Pduggs]

15 minutes ago, Chargerman said:

My coach came with the 8 house batteries with 4 of them being in the rear compartment. The reason that the second set of 4 are in the rear compartment is because they were an option. When not ordered this allowed this rear compartment to be used for storage. The extra 4 batteries were provided when a residential fridge was chosen as an option. From my experience with my setup is that they last a lot longer than 4 years if maintained and charged properly. Regarding the longevity of the steel trays I coated mine with 2 coats of POR-15 and this has made them stay like new for years. A key to this is also setting the charge rates properly. When I got the coach the settings were too high and it boiled the batteries when charging. With the correct settings this is eliminated 

Good points. Thanks  

Are you setting the Charge Rate at 80%?  I had some battery acid on mine, but I suspect it was caused by my overfilling.

Do you know where I can buy a battery slide tray for my aft compartment?  

[rpasetto]

6 minutes ago, Chargerman said:

My coach came with the 8 house batteries with 4 of them being in the rear compartment. The reason that the second set of 4 are in the rear compartment is because they were an option. When not ordered this allowed this rear compartment to be used for storage. The extra 4 batteries were provided when a residential fridge was chosen as an option. From my experience with my setup is that they last a lot longer than 4 years if maintained and charged properly. Regarding the longevity of the steel trays I coated mine with 2 coats of POR-15 and this has made them stay like new for years. A key to this is also setting the charge rates properly. When I got the coach the settings were too high and it boiled the batteries when charging. With the correct settings this is eliminated 

What are the settings you recommend?

[Chargerman]

Mine was boiling at the 90% rating that the previous owner had it set at. A fellow Monaco techie recommended 80%. Went to that rate and all is well. 

[rpasetto]

Thanks,  I'll check settings on mine

Rick P 05 Sig

[Chargerman]

Regarding the need for a new battery tray, I don’t know where you could find one but I think I would locate a local metal fabrication shop and have them make one out of stainless. Will cost more but you won’t have to worry about it again

[Tom Cherry]

I am of the Buggy Whip school.  Flooded 225 Amp Hour Trojan T-105's are my choice.  SOME of the Monaco's came with the TALL batteries... if you do the math on them the  GC-2's are way more economical.  The additional 20 - 25% that you get from the taller one's costs you 3 times (memory) the $/Amp Hr for the incremental difference.  Plus the backache of installing or removing them.  May have changed....but finding the GC-2

Now, many of our older members actually talked to the design engineers (or perhaps the Pillow Arrangers as out dear Colonel called them).  The reason, I believe that the batteries are all in one area is two fold.  One is the rear axles are easier to carry the load.  If you added in the weight of the cranking batteries to the front axle....that would probably be an additonal 150 pounds.  On the Camelots and some similar ones, we run at 95% of the weight due to the fuel cell size and placement.

Second....there would be a very long run of cabling to charge the batteries and you would also have the potential voltage drop (cable length loss) from the front to the rear....where the Charger/Inverter is located.  If you snoop around and look at the Rear Run Bay, it is very compact and your Big Boy solenoid or Battery Boost and BIRD Charging device is there.  That would be a monster to install and have BIRD charging if they were up front.

As to Charging Rates....Magnum's Default settings (via the remote or from the defaults built into the Inverter itself..)..80% Charging.  I have a busted Remote and had to do a factory reset of my inverter until I could get a replacement.  The rest includes the basics.  80% Recharge Rate and 450 Amp Hours Size (capacity) and FLOODED for the type.  If you read the Magnum inverter manual or the Remote manual, the programming sequence calls out the "Default Values" for every programmable parameter.  Obviously the Remote has MORE options and the ARC vs the RC-50 has different levels of settings.

One SHOULD check the program on a NEW (to them?) MH and verify what is set and where.  Typically, Magnum will over the phone walk you through the settings.  MOST choose NOT to enable the SEARCH WATTS function of 5Watts.  SOME disable and some set higher.  Magnum can explain as "recommend".

As to LIFE....no one has mentioned the basics.  Unless you do a lot of boondocking, then once a year or maybe 2X per year, you need to DRAW down the batteries or exercise them.  That keeps them TUNED UP and they will last longer.  Trojan goes into detail when you call.

Also maintaining the Electrolyte level is critical.  It should be about 1/2 to 2/3's of the distance between the TOP of the plates and the bottom of the well.  Trojan ships theirs at 75% to make sure that they don't evaporate.  

The easy way...  Use a 350 watt load (small heater or a work light) and charge up the batteries.  Test the Electrolyte with a Hydrometer with a SCALE....Floating balls don't get it.  record the values and the individual or the Series connected pair.  Make sure the level is ok.

THEN....drain them down and monitor the actual Voltage (assuming that you test each).  When you get 6.0 VDC, then stop.  That is about 50%.  NOW....when you stop, the batteries will have to stabilize for an hour or so....or you have to disconnect the load.  The 6 VDC is the OPEN (no load) Voltage.  When fully charged, the voltage will be (memory) 6.36 VDC and the Specific Gravity will be 1.278.  

Each time you drain them, assuming they are not shorted or have not been abused, they will improve.  After 3 cycles.....what you read and see...freshly charged....is the BEST you will get.  typically, a set of well maintained Trojans will delivery 90% of the SOC when they are about 5 - 6 years old.  May drop to 80% at 9 or so.  

That is WAY more poser than is needed to safely operate a Res Refer for 24 hours....assuming you do a 3 Hr Genny Run (or shore) every 24 hours.  SO, unless you are a boon docker....then a properly maintained set of Trojans will last a long time.

UNFORTUNATELY....not so, or so says many experienced techs.  LazyDays techs said that when a customer brings in a set of Interstates that were run down and had low electrolyte level, there was maybe a 20% chance of salvaging (refilling, recharging, load drain, etc).  However, there was an 80% chance with the Trojans.

Trojan T-105's sell in the $100 - $120 range....which is usually price competitive with the UPPER END 225 AMP HOUR Interstates.  NOW....some will say that Costco or others sell them way cheaper.  I bought one for a golf cart.  YES...cheaper.  But, if you looked at the plate data....it was about 190 Amp Hours and the weight was less than the specs (from the Interstate website) of the REAL TOP END 225 amp hour ones.  SO....compare before you buy....make certain that you are getting the original Interstate OEM battery or the best one.  Monaco, I THINK used them...

My understanding.....others might differ....

A word of caution....and some may have evidence to the contrary.  if you abuse or have a charging issue with an AGM, then you likelihood of toasting it is HIGHER....  Don't know about the Lithiums.  SO....if your constantly monitor and full understand (like having the Magnum BMK installed and KNOW what you are reading and WHAT it is telling you and FULLY understand HOW the 3 stage Charging works and such...THEN you are probably "Battery Smart ENOUGH" to purchase AGM's .  If all the above is Greek and you don't know a BMK from a BLT, then read....otherwise....Flooded may be the best for you.

ONE FINAL thought.  Several members here, including me, use the Water Miser Caps.  They will prevent electrolyte loss.  They are cheaper than the self filling system.  SO....adding them is a wise and cost effective choice... I barely add water to mine....

[Pduggs]

4 hours ago, Tom Cherry said:

I am of the Buggy Whip school.  Flooded 225 Amp Hour Trojan T-105's are my choice.  SOME of the Monaco's came with the TALL batteries... if you do the math on them the  GC-2's are way more economical.  The additional 20 - 25% that you get from the taller one's costs you 3 times (memory) the $/Amp Hr for the incremental difference.  Plus the backache of installing or removing them.  May have changed....but finding the GC-2

Now, many of our older members actually talked to the design engineers (or perhaps the Pillow Arrangers as out dear Colonel called them).  The reason, I believe that the batteries are all in one area is two fold.  One is the rear axles are easier to carry the load.  If you added in the weight of the cranking batteries to the front axle....that would probably be an additonal 150 pounds.  On the Camelots and some similar ones, we run at 95% of the weight due to the fuel cell size and placement.

Second....there would be a very long run of cabling to charge the batteries and you would also have the potential voltage drop (cable length loss) from the front to the rear....where the Charger/Inverter is located.  If you snoop around and look at the Rear Run Bay, it is very compact and your Big Boy solenoid or Battery Boost and BIRD Charging device is there.  That would be a monster to install and have BIRD charging if they were up front.

As to Charging Rates....Magnum's Default settings (via the remote or from the defaults built into the Inverter itself..)..80% Charging.  I have a busted Remote and had to do a factory reset of my inverter until I could get a replacement.  The rest includes the basics.  80% Recharge Rate and 450 Amp Hours Size (capacity) and FLOODED for the type.  If you read the Magnum inverter manual or the Remote manual, the programming sequence calls out the "Default Values" for every programmable parameter.  Obviously the Remote has MORE options and the ARC vs the RC-50 has different levels of settings.

One SHOULD check the program on a NEW (to them?) MH and verify what is set and where.  Typically, Magnum will over the phone walk you through the settings.  MOST choose NOT to enable the SEARCH WATTS function of 5Watts.  SOME disable and some set higher.  Magnum can explain as "recommend".

As to LIFE....no one has mentioned the basics.  Unless you do a lot of boondocking, then once a year or maybe 2X per year, you need to DRAW down the batteries or exercise them.  That keeps them TUNED UP and they will last longer.  Trojan goes into detail when you call.

Also maintaining the Electrolyte level is critical.  It should be about 1/2 to 2/3's of the distance between the TOP of the plates and the bottom of the well.  Trojan ships theirs at 75% to make sure that they don't evaporate.  

The easy way...  Use a 350 watt load (small heater or a work light) and charge up the batteries.  Test the Electrolyte with a Hydrometer with a SCALE....Floating balls don't get it.  record the values and the individual or the Series connected pair.  Make sure the level is ok.

THEN....drain them down and monitor the actual Voltage (assuming that you test each).  When you get 6.0 VDC, then stop.  That is about 50%.  NOW....when you stop, the batteries will have to stabilize for an hour or so....or you have to disconnect the load.  The 6 VDC is the OPEN (no load) Voltage.  When fully charged, the voltage will be (memory) 6.36 VDC and the Specific Gravity will be 1.278.  

Each time you drain them, assuming they are not shorted or have not been abused, they will improve.  After 3 cycles.....what you read and see...freshly charged....is the BEST you will get.  typically, a set of well maintained Trojans will delivery 90% of the SOC when they are about 5 - 6 years old.  May drop to 80% at 9 or so.  

That is WAY more poser than is needed to safely operate a Res Refer for 24 hours....assuming you do a 3 Hr Genny Run (or shore) every 24 hours.  SO, unless you are a boon docker....then a properly maintained set of Trojans will last a long time.

UNFORTUNATELY....not so, or so says many experienced techs.  LazyDays techs said that when a customer brings in a set of Interstates that were run down and had low electrolyte level, there was maybe a 20% chance of salvaging (refilling, recharging, load drain, etc).  However, there was an 80% chance with the Trojans.

Trojan T-105's sell in the $100 - $120 range....which is usually price competitive with the UPPER END 225 AMP HOUR Interstates.  NOW....some will say that Costco or others sell them way cheaper.  I bought one for a golf cart.  YES...cheaper.  But, if you looked at the plate data....it was about 190 Amp Hours and the weight was less than the specs (from the Interstate website) of the REAL TOP END 225 amp hour ones.  SO....compare before you buy....make certain that you are getting the original Interstate OEM battery or the best one.  Monaco, I THINK used them...

My understanding.....others might differ....

A word of caution....and some may have evidence to the contrary.  if you abuse or have a charging issue with an AGM, then you likelihood of toasting it is HIGHER....  Don't know about the Lithiums.  SO....if your constantly monitor and full understand (like having the Magnum BMK installed and KNOW what you are reading and WHAT it is telling you and FULLY understand HOW the 3 stage Charging works and such...THEN you are probably "Battery Smart ENOUGH" to purchase AGM's .  If all the above is Greek and you don't know a BMK from a BLT, then read....otherwise....Flooded may be the best for you.

ONE FINAL thought.  Several members here, including me, use the Water Miser Caps.  They will prevent electrolyte loss.  They are cheaper than the self filling system.  SO....adding them is a wise and cost effective choice... I barely add water to mine....

Lots of good points there. I’ve been debating whether to replace my 1.5 year old flooded Duracell batteries with lithium. We plan to boondock some next winter in the desert, but generally we don’t boondock much. So I hate to spend so much money, when flooded are so cheap relatively speaking and so reliable. 

[Chargerman]

Thanks very much Tom. Great info and detail!

[slvfox1954]

On my '05 Windsor, I removed the chassis batteries and moved them into the engine compartment with a custom battery bracket. I then put four more house batteries into the battery compartment. I normally use Interstate batteries directly from Interstate and they last about 5-6 years. This time I replaced them with Trojans. Hopefully I can get longer life out of these.

We almost always boondock with a residential fridge and never had a problem. I do use a small 2000W generator which I start about 7-8  so the wife can watch TV and cook. I will run it until about 10  pm to charge the house batteries for the night.

Tim

05 Winsor PDQ