Engine Battery Trickle Charging ?

MeRob

Member
I should have checked !
As I understand it, the engine battery in my Sprinter RV is ONLY being charged when the engine is running. Hmmm

Since most RVs are 'stored' (4-months?) between periods of use... one might expect that both the coach and the engine batteries would covered by your shore power during that stored period. I guess not.

Both my engine and diesel generator are run until they and their exhaust systems are well warmed up... at regular intervals during the Winter. So far so good...but...

Is anyone using a Trickle Charger on their engine battery during storage? Rob
 

bcislander

'07 Mercedes-badged Dodge
I do.

The van is connected to shore power to keep house batteries in good shape. The trickle charger is connected to one of the house AC power points. Its DC O/P is connected to the lower, always ON, 12V DC power socket.

BTW, IMO, you are usually better off not starting the engine during storage. The engine & exhaust systems are unlikely to get up to operating temperatures without driving. It's better to make sure that all systems are 'hot' before you store the van, then just leave it. Maybe check under the hood periodically to ensure that no mice have made a nest there.
 

MeRob

Member
Obviously, I too... have been wondering if I really needed a Trickle Charger to maintain my Chassis Engine Battery during it's Winter storage.
After taking the time to carefully re-examine my Fleetwood Owner's Manual... I ran across the following:

"Both sets of batteries will be kept charged by the chassis engine alternator and charging system while you are driving"
" The DC power converter will charge the chassis and house batteries when plugged into 120-volt AC service or by the generator (if equipped)."

Unless I have missed something...(which is entirely possible) ...I would appear that my Engine Battery is indeed being being topped-up along with my House Batteries, by 120V shore power. Maybe worth checking out? Makes sense to me....
 

pfflyer

Well-known member
I don't have a Fleetwood but my starter battery lasts about 3-4 weeks. I use a trickle charger for both batteries. If you leave yours plugged in probable the easiest way to maintain the starter is with a battery tender plugged into a chassis 12v outlet.
 

smiller

2008 View J (2007 NCV3 3500)
Some electrical systems have a lower or higher parasitic draw than others, some battery types have a lower or higher self-discharge rate than others, etc. You can try to assess all that and then take into account how long the vehicle will be idle and determine whether standby charging is needed, or you can just... use a float charger and be done with it.


.
 
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bcislander

'07 Mercedes-badged Dodge
Obviously, I too... have been wondering if I really needed a Trickle Charger to maintain my Chassis Engine Battery during it's Winter storage.
After taking the time to carefully re-examine my Fleetwood Owner's Manual... I ran across the following:

"Both sets of batteries will be kept charged by the chassis engine alternator and charging system while you are driving"
" The DC power converter will charge the chassis and house batteries when plugged into 120-volt AC service or by the generator (if equipped)."

Unless I have missed something...(which is entirely possible) ...I would appear that my Engine Battery is indeed being being topped-up along with my House Batteries, by 120V shore power. Maybe worth checking out? Makes sense to me....
A voltmeter would confirm your Owner's Manual statement. Measure the chassis battery voltage before connecting your van to 120V. It should be ~12.6V or so after sitting for a while. That voltage should rise to over 13V when you connect the van to 120V, or run the generator.

The only other concern might be what type of converter was installed. For long term battery charging/maintaining it should have a three stage charging profile that serves as a battery 'maintainer' after the batteries are fully charged. Your Owner's Manual or equipment list should have a converter Make/Model, then Google should give you the specific charging profile.
 

MeRob

Member
I agree... I'll have to check it out to be certain as to what type of charging is taking place when my RV is 'stored' and on AC power only.
I contacted Fortron Power (my converter manufacturer)... and their reply, as brief and not impressive as it was, stated only that the converter should be connected to the Coach Batteries ONLY. So be it... I'll deal with it. Thank you all! Rob
 

MeRob

Member
Update:
It appears that Fortron Power (RV ) is no longer in business ? No wonder detailed information is scarce.... Ha!
 

Old Crows

Calypso 2014 View Profile
:2cents:

Your Fleetwood's charging system operation sounds like the typical RV. It's sort of industry standard practice. Helps keep you from accidently flattening your starter battery.

If you have a panel with a meter, LCD or led state of charge indicator you can easily verify. Turn on the coach ster and check the SoC. Start the engine. Bot the chassis and coach batteries should start indicating a higher SoC. On shore or genny, only the chassis bank should indicate higher.

If hour batteries are in good condition and nearly, or near, fully charged they should not need 24/7 charging while laid up. They should be able to go 6 - 8 weeks and need only a short boost to bring them up to near full. Absolutely no need to have it on shore power 24/7, especially if you don't know if your charger is a multi stage/maintainer to avoid cooking your batteries.

Does your Sprinter have an always hot cigar lighter on the dash? Yes? If you have shore power, you can charge the coach and chassis battery at the same time by using a maintainer/ charger and plugging into the cig ligher with a cig adapter. Plug the 110v line into a receptical while on shore power.

http://www.batterychargers.com/sp3-ca/

Easy peezy. Simple.
 
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eightyeightkeys

New member
I was advised by Fleetwood that the chassis battery gets charged after the house batteries reach a certain voltage. I forget what the exact voltage was but basically "full."

However, the unusual "step" ? that I have to make is to make sure "AUX" is ON before plugging in to shore power OR to press the AUX toggle ON after plugging into shore power to make sure that the charging system is ON. I can then hear the fan of the Invertor/Charger engage and all is good.

I guess I find this "unusual" because when we're plugged into shore power the AUX light is already ON, glowing red, and then only way to make sure your charging is to listen for the fan under the fridge when you toggle the AUX one more time.
 

MeRob

Member
Right! ! My Coach Batteries (two 6-volts) show 13.65 V with AC connected. Probably a steady converter charge rate? I've been trying to figure out if my existing Converter is single or 3-stage...without having to pull the whole assembly apart (in the cold and in the dark!).
Regardless of what my Fleetwood manual says... I doubt that the chassis battery in a RV, is maintained by the coach converter. Therefore a Trickle Charger makes sense. And considering the cost of having to replace two 6V Coach Batteries, I may also invest in a new 'smart' Converter while I'm at it.
As always, Thanks for the help!... Rob
 

MeRob

Member
You are indeed WISE Old Crows !
Coach Batteries Question solved ! I was advised (on the web) that the World Friendship Company had dropped out of the RV Power business. Hmmm...I guess not. Ha! Maybe new converter... and definitely a Trickle Charger for the engine battery. Whew! Even when it's parked, it costs money! Thanks again! Rob
 

ryangruhn

New member
Is there anywhere under the hood of a 2010 Mercedes Sprinter to connect a trickle charger?
 

Boxster1971

2012 Sprinter 3500 Ext
Is there anywhere under the hood of a 2010 Mercedes Sprinter to connect a trickle charger?

Yes - there is a positive (+) jump-start connection under the red circular cover in upper left side of engine compartment. Also a negative (-) ground stud on left hand sidewall in engine compartment.




Sent from my iPad using Tapatalk
 

Old Crows

Calypso 2014 View Profile
The under hood connections may be one way. On our 2010, that worked. Didn't work on our 2013/4. I think the + and - are not connected to the battery in the 2013. You have to engage the starter or turn the ignition on. Just a guess. Much easier to use the 'always hot' cigar lighter socket' at the in the lower part of the center console.
 
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MeRob

Member
So much for the 'rumour' that my Fleetwood coach battery will keep my chassis battery topped up. I don't think so...
Tested the chassis battery voltage today. It's 11.8 V ... that's with or without the coach being connected to shore power. ( Coach Battery Monitor still indicates Coach and Chassis Batteries as being "Fully Charged")
However, now I'm wondering what charging amp rate would be suitable to trickle charge a 100 amp 12 V battery? ... Rob
 

MeRob

Member
An interesting observation... My coach has a Monitor Board that amongst other things, displays the existing 'charge' state of the MAIN and AUX Batteries.
I guess it's a question of interpretation... I thought MAIN meant the Chassis Battery... and AUX meant my Coach 6V-pack. WRONG!
That's the trouble with first impressions...right or wrong, they have a tendency to stick in your mind like poop on a blanket. This issue now solved.
My Trik-L Charger is on it's way. Thank you all! Rob
 

MeRob

Member
The plot thickens... After examining Fleetwood's battery schematics... I noticed a relay connecting AC powered converter charging circuit between both the Chassis and Coach batteries.
I contacted Fleetwood and was advised... that after the Coach batteries are fully charged (13.1 Volts) ...the relay WILL THEN, if necessary, begin charging the Chassis battery.

A great concept that isn't working in my rig.(my Chassis battery was at 11.7 Vots and falling before I intervened.

If this relay is in fact functioning, it might very well interfere with a Smart Converter's output. Just one more puzzle to work on over Winter.
 

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