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Topic: Chassis batteries needed charging.

Posted By: draboo on 12/30/14 10:49pm

I noticed that the chassis batteries were down to around 12.0 volts. The coach batteries are maintained well thanks to the inverter/charger system. I connected the chassis and coach batteries with a jumper to charge the chassis batteries for two days. I took off the jumper and the chassis batteries were at 13 volts. Now, a day later, they are down to 12.5 V.

Is this a normal voltage drop? Might they need replacing? I thought the inverter charged all the batteries, not just the coach.

Thanks for any info.

Brad
02 Holiday Rambler Neptune 34ft DP


Posted By: MrWizard on 12/30/14 11:11pm

maybe..maybe not

some RVs have the "BIRD" system which will charge both sets from what ever source is available, giving priority to primary set of that source

BIRD = Bi-Directional Relay system

when charging from shore or generator it charges the house first then includes the chassis, after the house reaches 13.2

when charging from alternator it charges the chassis first, then the house

you may have a BIRD that has malfunctioned
or you might not have a dual control system BIRD at all

not ALL RVs have this system, mine does not


Radiate The Happy
....

Connected using Verizon and AT&T
1997 F53 Bounder 36s



Posted By: tahiti16 on 12/30/14 11:38pm

Couple things make sure you check the water in the chassis battery, low water will cause faster discharge. 2 make sure and check voltage 10-30 minutes after you disconnect the charger as the battery will show an artificial level right after disconnecting.
3rd if you are really drawing it down that fast either you are using something you don't realize is attached to chassis not the house batteries or something could be miswired causing the extra draw.

As Mr. Wizard stated some have an interconnect some don't and some are just broke.


Ray, Cheryl & of course Miss Molly the four-legged child

2006 Dolphin 36' F53 V10 5 speed auto 2 slides 7.5 KW genset



Posted By: draboo on 12/31/14 12:52am

The batteries are the "maintenance free" type. I will try charging them again and check after a half hour. They do look rather old. I replaced the coach batteries when I bought it 3 months ago.

Thanks for the info,eh?

Brad


Posted By: accsys on 12/31/14 03:30am

We have found the Trik-L-Start to be a very good solution to this problem. It connects between the house and starting batteries to provide a charging current to the starting batteries anytime their voltage is less than the house batteries. It will supply up to five amps charging current. It's big brother, the Amp-L-Start, works similarly but supplies up to 15 amps charging current. What's nice is they are install and forget about them. They work as advertised.


John & Doris
Doris and Robbies Blogs
2007 Tiffin Phaeton QDH 40 w/Cat 7 350 (Mothership)
2004 Liberty Renegade 4x4 Toad (Libby)
Roadmaster Falcon 2 tow bar
Air Force One toad braking system
FMCA F380583, PA, Good Sams




Posted By: ksg5000 on 12/31/14 04:40am

Have you battery load tested - most tire/auto places with test for free. If you don't have Bird system then consider purchasing a Trik L Start - they are inexpensive, easy to install, and will maintain your coach battery.


Kevin


Posted By: Ivylog on 12/31/14 05:43am

Most Monaco's do not charge the engine batteries on shore power. How big/long of a jumper did you use? Many maintenance free batteries have caps, but they are under the hard plastic top and with some pressing with a screw driver they can be found... usually as a set of three.
If you clean the tops you may find some indication of how old they are and if they are Interstate they could be original.
I would disconnect one battery at a time and see if the other by itself will start your rig. I did that is past summer at a rally before the Interstate battery guys came to check my 03 batteries and had decided to not replace them BUT they let me keep my old ones so I replaced them.
PS: they are still going strong in a 24V machine at home.


This post is my opinion (free advice). It is not intended to influence anyone's judgment nor do I advocate anyone do what I propose.

08 HR Navigator 45'
Sold 04 Dynasty after 14 great years.
[url=https://i.


Posted By: Pass42 on 12/31/14 06:16am

In my coach, the carbon monoxide & propane detectors as well as the steps are wired to the chassis batteries.....as is the engine computer....left alone, my chassis batteries will go flat in 2 -3 weeks from these parasitic loads...


2017 Montana High Country 375FL
2015 Ram 2500 Heavy Duty, Cummins 6.7, factory tow package, factory snow plow prep package


Posted By: mike brez on 12/31/14 08:17am

I wired this in.

[image]


1998 36 foot Country Coach Magna #5499 Single slide
Gillig chassis with a series 40
02 Ford F250 7.3 with a few mods
2015 Wrangler JKU


Posted By: Coyote74 on 12/31/14 08:24am

If u leave antenna booster on it will pull bat down over time.


Joe Taylor , Good Sam Life Member
FMCA #285032
2004 Winnebago Adventurer 38R

Life's a trip, RVing makes it an incredible journey.


Posted By: pianotuna on 12/31/14 08:54am

Hi,

I would add a trik-l-start or amp-l-start. (my personal choice was the trik-l-start).


Regards, Don
My ride is a 28 foot Class C, 256 watts solar, 556 amp hours of AGM in two battery banks 12 volt batteries, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.


Posted By: MrWizard on 12/31/14 10:36am

30 min is not enough charge time
Try six hours with the charger, then let them rest over night and then check them


Posted By: lanerd on 12/31/14 11:17am

I had a Safari that was probably the same as your Neptune. It did NOT charge the chassis batteries when on shore power. I installed a Trik-l-start and never had another problem with the chassis batteries.

FWIW, 12.5 to 12.6 volts is indication of a full charge. You will only read higher when the batteries are being charged. So going from 13v down to 12.5 is normal when the charger has been turned off. When measuring a battery, turn off the battery disconnect and wait for about a 1/2 hour before measuring.

Purchase and install the Trik-l-start....it will solve your problem.

Ron


Ron & Sandie
2013 Tiffin Phaeton 42LH Cummins ISL 400hp
Toad: 2011 GMC Terrain SLT2
Tow Bar: Sterling AT
Toad Brakes: Unified by U.S. Gear
TPMS: Pressure Pro
Member of: GS, FMCA, Allegro


RETIRED!! How sweet it is....


Posted By: Motor7 on 12/31/14 12:09pm

Thanks for the info on the Trik L Start....I just ordered one from rvupgradestore for $35.75 shipped.......[emoticon]


Posted By: Gjac on 12/31/14 01:08pm

draboo wrote:

I noticed that the chassis batteries were down to around 12.0 volts. The coach batteries are maintained well thanks to the inverter/charger system. I connected the chassis and coach batteries with a jumper to charge the chassis batteries for two days. I took off the jumper and the chassis batteries were at 13 volts. Now, a day later, they are down to 12.5 V.

Is this a normal voltage drop? Might they need replacing? I thought the inverter charged all the batteries, not just the coach.

Thanks for any info.

Brad
02 Holiday Rambler Neptune 34ft DP
I have a maintenance free chassis battery also from Walmart. I put a battery disconnect on it and it dropped from 12.6v on Nov 4th to 12.5 v on Dec 31st. House batteries were 12.6 to 12.4v for the same time frame. So no that is not a normal voltage drop for one day. All the batteries are 8 years old. The easiest way to tell if your chassis battery is being charged along with your house batteries when you are plugged in is to check the voltage at the pos and neg terminals and if you see around 14 v it is charging.


Posted By: lanerd on 12/31/14 03:06pm

Yes, with all due respect, a drop from 13v (meaning the batteries had just been on a charge cycle and is dropping back down to their normal full charge) to 12.5 is most definitely normal, especially if the batteries) are several years old. The OP's mh is an 02 and he just got the mh 3 months ago, so we really don't know how old his chassis batteries really are.

If the batteries have been charging, then it's important to let the batteries set for 2 to 3 hours without a load or charger connected to stabilize before testing. Otherwise, the reading will be high, caused by a phenomenon called "surface charge"; hence, the reading of 13v.

He measured the voltage immediately after charging to get the 13v then the next day he only had 12.5. So depending upon how old the batteries are and the amount of parasitic load that was present, the drop is definitely normal.

Ron


Posted By: mike brez on 12/31/14 03:12pm

pianotuna wrote:

Hi,

I would add a trik-l-start or amp-l-start. (my personal choice was the trik-l-start).


Just curious why the trik over the amp? I thought through reading the amp is a upgraded trik.


Posted By: pianotuna on 12/31/14 04:45pm

Hi,

Seeing as 5 amps is enough to maintain a chassis battery, there really is not much point in doing the amp-l-start. The two devices do work a bit differently. The trik-l-start doesn't do an over voltage protection and the amp-l-start does. Where I live, I want the extra voltage because of extreme low temperature.

The whole idea of both units is to act as a maintainer, not a charger.

I also did not want a beeper going off.

mike brez wrote:

pianotuna wrote:

Hi,

I would add a trik-l-start or amp-l-start. (my personal choice was the trik-l-start).


Just curious why the trik over the amp? I thought through reading the amp is a upgraded trik.



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