Battery life boondocking

Belgique · 05-10-2006, 06:47 AM

We're doing our first boondocking with the 35U at a COE park and are surprised at battery life. These are new, honker sized, deep cycle batteries yet they seem to drain faster than expected.

The first night they were gone in hours. I am thinking that the culprit was leaving the rectifier on with the laptop on? We used almost nothing else except some lites (2).

Yesterday, we did not run the genset after 8AM. We used some water and a light or 2 and the XM radio. By 7PM the batteries were very low.

Also, I was surprised that the genset starts using the house batteries...almost didn't get it started. The manual says that this is the correct hookup.

What are we doing wrong, if anything?

Thanks! Steve

kenbt · 05-10-2006, 07:59 AM

Battery life seems to be a real problem in the last couple of years especially I find with Winnebago coaches. They are installing so many appliances that have a constant draw on the batteries. Make sure you don't have the Interstate Workaholic series 31 batteries...they are a problem and Interstate is aware of it. They swap them out for their series 29 battery, which is close in AH rating with less problems

bflem · 05-10-2006, 09:37 AM

If your coach batteries are too low to start the generator you can start your engine and it will put some charge in the coach batteries to assist the starting of the gen.

RVingnuts · 05-10-2006, 11:01 AM

As Kenbt stated, check if you have Group 31s. If you do, please call Interstate and they will exchange under warranty to Group 29s. However, if your tray allows the size, change to 4 6Volts Golf Carts at 225AH. I did it and have never had a problem after it. Connect in series and then in parallel and you will have 450AH instead of the current 345AH (3 X 115AH) you have. The golf cars cost exactly the same as the Group 29s and then you buy a additional battery.
I would also recommend you check the solution in the batteries as well as the elements. Check if you have traces of losing solution on the batteries (potential boiling of the plates) as you might have some defectve batteries also. If you don't, complete the solution if necessary and give them a good equalize charge. If you don't know, please PM me and I will explain what you need to do. If you do not have a good 3 stage external charger (not the one on the motorhome) then you will have to do this in a good battery shop.
Here are the pictures of my installation:
Journey 6Volts Golf Cart Batteries

bobpie · 05-10-2006, 12:32 PM

Thats odd, we use the front tv, stereo, fridge,heater,lights,convertor for the front tv, satelite KVH ant., and can go all night in the colder weather. Then we start the gen up and make coffee and charge up. Just my luck.

AFChap · 05-10-2006, 06:51 PM

1 - You should have a "battery boost" switch, maybe on the dash, that will link your chassis and house batteries together to start the genny when the house batteries are too low. It also works to start the coach when the chassis batteries are low. The genny starts off the house batteries for exactly that reason ...whichever battery bank is low, you have another bank of batteries that should get you going.

2 - If your batteries are not lasting as long as they used to, they may need to be equalized ...the process de-sulfates the battery plates and restores their charging capacity. Many inverters can be put into an equalizing cycle ...you'll need to check your manuals to find about about yours. Equalizing is recommended 2-3 times a year in my manual.

I have a Freedom Model 15 (1,500 watt) inverter with Heart interface & Xantrex control panel. Below is the equalizing procedure I developed from my manuals and from a talk with a Coachnet tech.
1. Never equalize gel batteries or maintenance free batteries.
2. The batteries should be fully charged (charger in "float" mode) and near ambient temperature before beginning an equalize charging cycle.
3. There should be a sufficient amount of electrolyte in each cell to cover the plates, but do not top-off each cell until after equalizing. Full cells may "spit" electrolyte during the process.
4. Leave the caps on each cell. It is a good idea to lay a paper towel over the caps. This makes it easy to spot a cell that may start spitting electrolyte, and will soak up the liquid if this does happen.
5. Open compartment doors and pull out house battery tray to ensure sufficient ventilation for batteries. Avoid smoking or generating sparks or flame near the batteries during equalizing.
6. All DC loads on the batteries should be turned OFF (this includes heating and cooling as thermostats and igniters require DC power) and disconnected. The easiest way to disconnect DC powered items is to use the battery disconnect switch. Since the battery voltage will be higher than normal during the charge cycle, some DC equipment could be damaged if left ON. While the battery disconnect switch is tripped, you will not have lights, power to refrigerator control board, or power to thermostats (therefore refrigerator, a/c, heat pumps, and furnaces will not operate ...not even on LP).
7. Begin equalizing by first turning ON the charger and waiting until it goes into the float mode.
- Then press the SETUP button and hold it until the SETUP LED begins to flash.
- Release the SETUP button and immediately press both the SETUP and CHARGE buttons simultaneously and hold apx five seconds until the 3 battery LEDs begin to flash in sequence
- To terminate the equalizing cycle and force the charger into float mode, press the CHARGER button.
8. The cycle will automatically terminate after 8 hours or if AC input power to the charger is interrupted.
9. After the equalizing cycle has completed, check fluid levels in each battery, topping off as necessary.

The Godfather · 05-11-2006, 05:29 AM

Steve, our first time out dry camping in our brand new 35A the batteries went after a couple of hours. Next day I drove the unit to an auto repair shop and found the batteries were defective. replaced with new ones and Winnebago reimbursed me. kenbt is right about the new MHs drawing more juice at rest than our grandfathers did. Consider adding solar panels if you plan to continue to dry camp. I would suggest 200 watts worth. We use the state parks in CA as much as we can so we really rely on solar. good luck,

Dick

Hikerdogs · 05-11-2006, 05:46 AM

Belgique: When you say the batteries are the "the new honkier sized ones" do you mean they are no longer the original batteries, or that they are larger than ones in previous models?

If they're the originals they have long exceeded their life expectancy. We had to replace ours last year and found out that most deep cycle batteries last less than the expected 4 years because they have been discharged below the minimum recovery level to often.

AF Chap I would agree with your charging & equalization method except for the following:

Quote:

Leave the caps on each cell. It is a good idea to lay a paper towel over the caps. This makes it easy to spot a cell that may start spitting electrolyte, and will soak up the liquid if this does happen.

It is not recommended to leave the caps on the battery cells when charging. The vent holes in the caps are less than 1/16" in diameter. If they become plugged there is no way for the hydrogen being generated to escape. The resulting accumulation could cause the cap to blow off or worse. You wouldn't want a nasty surprise when you tried to remove the cap to check the water level. At the very least I would pull the caps off and let them gently rest over the cell openings. It's best to remove them all together.

5. Open compartment doors and pull out house battery tray to ensure sufficient ventilation for batteries. Avoid smoking or generating sparks or flame near the batteries during equalizing.

I believe the Sunflyer has 2 house batteries (ours are the maintenance free variety) under the entry stairs. There is no slideable tray, so the only way to assure proper ventelation is to remove the top stair tread, open some windows, and leave the entry door open.

JamesOne · 05-14-2006, 09:26 AM

Quote:

You should have a "battery boost" switch, maybe on the dash, that will link your chassis and house batteries together to start the genny when the house batteries are too low.

Can someone direct me to a manual or wiring diagram that shows this to be true? I know it works the other way in that the house batteries can be used to start the main engine but I didn't know the chasis batteries could be used to start the genset.

AFChap · 05-14-2006, 05:28 PM

Quote:

Can someone direct me to a manual or wiring diagram that shows this to be true?

I can't point you to a manual or diagram, but I know it to be true because I have done it both ways ...the voice of experience

And the reason I tried it "backwards" when I needed it is that it just seems reasonable to me that if you tie the battery banks together, they are in fact tied together either direction you need the current to flow!

JamesOne · 05-15-2006, 01:55 AM

1. Let me assure you I am not trolling.

2. I completely forgot I had called Winnebago on the question of using the Aux Start switch to start the generator.

3. My knowledge on this matter is limited to my coach, a 2005 Journey.

4. In this thread Lessons Learned, my post of Nov 2, 2005 clarifies it for my coach.

Belgique · 05-16-2006, 12:19 PM

Thanks for the counsel! Sorry did not answer sooner but we kept extending our stay at North Bend COE Park on Kerr Lake, VA. Just having too much fun.

We were more careful and managed but still surprised especially with the experience one of you posted about how much you run.

The batteries are brand new Interstate Boat/RV deep cycles. The data plate says "24M-HD, 500CA, 625 MCA". Don't know if is one of the series you mentioned?

Thanks again for the help! Steve

JD Allen · 05-16-2006, 12:29 PM

Quote:

Originally posted by kenbt:
Make sure you don't have the Interstate Workaholic series 31 batteries...they are a problem and Interstate is aware of it.

How can I tell if I have the series 31 battery? Mine are marked: SRM-24 550 CCA 690 MCA SPR

cbeierl · 05-16-2006, 03:38 PM

Quote:

SRM-24 550 CCA 690 MCA SPR

The 'SRM-24' indicates it's a size '24' battery, not a '31'.

vicsryd · 05-16-2006, 09:00 PM

SRM-24's are pretty small/low capacity for a class A motorhome. SRM-29's would be much more appropriate and is what most folks seem to have who have Interstate batteries (especially after the group 31 recall).

If you consider replacing your batteries and don't want to mess with converting to 6v golf batteries then you should consider upgrading to a AGM (absorbed glass mat) type battery. You can get more amp hours in the same size package, maintain voltage longer before dropping off, are more forgiving to exceeding 50% discharge and recharge to full more quickly. However, AGM do weigh more than lead acid batteries and cost about 30% more too.

Interstate has a group 31 AGM batteries (SCM31DM) whose physical dimensions will fit in less than a group 29 lead-acid space.

You can see for yourself at Interstate Marine/RV Batteries

This is on my list as soon as the current Interstate batteries need replacing..which so far doesn't appear to be anytime soon.

Tweke · 05-17-2006, 07:14 PM

So if I replace my Interstate 29's with four 6-volt batts, will I need to change/update/modify anything else in the electric system (charger, trik-l-start, etc.)?

Sounds like a good thing to do as soon as the warranty's up!

shastaron · 05-17-2006, 08:19 PM

6 Volts are the way to go. My local battery shop built me a special set of jumpers for $20.00. They gave me the directions for proper wiring. It was incredible the difference.

I then added two solar panels. Is great for keeping everything charge and makes the battery life longer because of no storage draw downs. When dry camping it lets us go for a couple of days without any charging.

ajbjrvers · 05-18-2006, 01:28 AM

To, Tweke and others re; change from 12 volt to 6 volt batteries.

Space is a factor in considering change; you need 2 6 volt batts to replace 1 12 volt batt.
If not enough room in current location try to find space some place else.

6 volters are stronger and last longer for many reasons, but I'll let the more knowledgable tell you why.
There is more wiring involved but taking time to do it right is worth it.
The more amp hours you have, the longer the dry camping.

Look at my signature to see my situation, it took awhile to get things up and started but it was worth it.

Thanks=== Aime===== AJBJRVERS=======

Tweke · 05-18-2006, 04:50 AM

It appears that I have the room - I'll measure carefully before I start!

So I take it that I don't need to change out anything else in the elec. system if/when I move to the 6-volt batts?

And ajbjrvers, you have a sweet system!

shastaron · 05-18-2006, 07:45 AM

In my Sightseer the fit was tight. Move the engine battery forward a little. Then place the four batteries in sideways. It was kind of like a puzzle.

Then make sure you wire correctly the two six volts act as one twelve, the other two six volts act as one twelve. Much larger storage, much slower draw down. Maybe somebody can post the wiring diagram or I will try and find mine and post it for you.