New Guy saying Hello...

Topic: New Guy saying Hello... (Read 1242 times) previous topic - next topic

New Guy saying Hello...

December 12, 2012, 05:35:13 pm

New guy checking in.

Just brought home a 99 U320. 62K miles on the chassis. 1450 hrs on the 450 Cummins and 450 hours on the genset. Interior of the coach is nearly perfect, exterior needs a buff and some decals removed or replaced. New tires/batteries.

This is not our first motorhome but it is our first pusher. I rebuilt my last one (A Provan Tiger on a 4x4 diesel chassis) to be all diesel/electric lots of battery and solar... Used all marine spec components, a 12V compressor fridge, etc etc.

I have some ideas about upgrades to the U320 but want to know specifics about battery charging when on the generator. I am assuming that the genset powers the inverter charger and is not using a 12V alternator directly. Is this correct?

Re: New Guy saying Hello...

Reply #1 – December 12, 2012, 06:31:11 pm

Yes. The gennie provides 110v for the inverter which includes a 3 stage charger.

Re: New Guy saying Hello...

Reply #2 – December 12, 2012, 07:30:22 pm

Welcome to the forum, hope you stick around. There seem to be a lot of 320 owners and others that can answer your questions as they are sure to arise.

Re: New Guy saying Hello...

Reply #3 – December 12, 2012, 07:43:10 pm

Welcome, I doubt you could pose a question here that someone won't have the answer to or direct you to the answer.
Richard B.

Re: New Guy saying Hello...

Reply #4 – December 12, 2012, 08:02:43 pm

One of our SUPER Members, Barry Brideau has a web site that will have at least 90% of the answers you need, FORETRAVEL Motorhomes service and Repair Information, the other 10% you can get here.

Welcome aboard!!!

Re: New Guy saying Hello...

Reply #5 – December 12, 2012, 09:22:02 pm

Thanks for the welcome...

The best upgrade we made to our last motorhome was to replace the ammonia fridge with a freon based system. This was easy in the last one as a small Norcold (12V Danfoss) was all we had room for anyway... I have read here on the household fridges some people are using and like the idea of it but I am not sure about what power upgrades would be complimentary. First thing to note is we have the ice-maker so that implies there is an inverter driven A/C plug behind the current fridge (Check). Plugged in is taken care of of course and running under the genset is also taken care of... Where my question comes in is driving. Are the house batteries charged with a combiner (other than the "boost" switch) while going down the road? If they are is there a provision that deals with the different charge profile of the AGM house batteries vs the lead acid starting batteries?

I used a Balmar external regulator (programmable charge profile and temperature sensing...) with success in the past and would consider adding this to the engine alternator. Another option is mounting a 2nd dedicated alternator to the engine with the Balmar isolated to the coach batteries...

Thoughts Comments Questions...

Re: New Guy saying Hello...

Reply #6 – December 12, 2012, 09:28:00 pm

You might be over thinking the problem. Several members travel all day and don't worry about the refer not having power. Other members have added a small, but big enough inverter just for the refer. The alternator is charging house and engine batteries when going down the road.

But there are lots of options to spend money, and great systems to be built. I am going to opt for the small inverter if I ever replace the old gas refer.

Re: New Guy saying Hello...

Reply #7 – December 12, 2012, 10:45:43 pm

Quote from: squeezer – December 12, 2012, 09:22:02 pm

Are the house batteries charged with a combiner (other than the "boost" switch) while going down the road? If they are is there a provision that deals with the different charge profile of the AGM house batteries vs the lead acid starting batteries?

Original/normal installation charges house and chassis batteries from the alternator through an isolator while the engine is running. The isolator is a pair of diodes with sufficient current and heat dissipation capacity to handle the requirements. The house and chassis batteries receive the same voltage from the alternator.

While parked and connected to shore power, the house batteries are charged from the inverter/converter according to the profile selected in the converter settings. The chassis batteries are not normally charged while parked. The "Boost" switch combines the batteries via a solenoid. Many folk use relays, switches, Trik-L-Start, etc., to charge/maintain the chassis batteries while parked. There can be some charging problems if the chassis and house batteries have different charging/maintenance characteristics.

We use AGM batteries for the house and the chassis. I added a Battery Tender Plus to maintain the charge on the chassis batteries while parked. The house batteries are maintained by the Freedom 25 inverter/converter.

If you search the forum, you will find many discussions of battery issues. There are many preferences about details and a lot of useful information that may guide your choices.

Re: New Guy saying Hello...

Reply #8 – December 12, 2012, 10:53:24 pm

Just to clarify Dave's reply, there is a diode-based isolator that the alternator feeds, which charges both house and engine batteries when the engine is running.

I installed a Whirlpool residential fridge in place of the old absorption unit and it has a dedicated 1 KW pure sine inverter. When we travel, we run with both the fridge and also with our separate compressor-based ice maker running. Steady-state load on the alternator during daytime driving is typically about 40 amps DC , running both fridge inverter and main inverter (powering the ice maker, computers, etc.). The solar panels are usually contributing another 15-20 amps.

Re: New Guy saying Hello...

Reply #9 – December 12, 2012, 11:14:12 pm

Quote from: Dave Katsuki – December 12, 2012, 10:53:24 pm

Just to clarify Dave's reply, there is a diode-based isolator that the alternator feeds, which charges both house and engine batteries when the engine is running.

I had not picked up on the isolator...

Where is it at?

Re: New Guy saying Hello...

Reply #10 – December 12, 2012, 11:20:18 pm

On ours (U270), it's on the back wall of the engine compartment. Blue, with 3 terminals and fins. I'm not sure about U320s, (but someone else will answer for sure.)

Re: New Guy saying Hello...

Reply #11 – December 12, 2012, 11:56:31 pm

Hi,
On my 1997 U320 the isolator is mounted on the frame rail, driver's side, just behind the drive wheels. It is with the boost solenoid. All exposed to the elements. Not good. Newer U320s have the isolator/electrics under the bed, on the engine box front wall. Here they are enclosed in a box with a thin, removeable plywood cover. The isolator/electrics are out of the elements on the newer coaches.
Welcome to the Foretravel club!
Raymond

Re: New Guy saying Hello...

Reply #12 – December 13, 2012, 06:59:19 am

Your 1999 320 sounds like mine. Approx. same hours and miles. We have had ours about 18 months and still learning. We changed out the ref-ridge with a residential unit and love the room and steady temps it provides.

Welcome to the Forforums, Phil

Re: New Guy saying Hello...

Reply #13 – January 15, 2013, 05:08:13 pm

My experience with running the refer (Dometic 7832, absorption) from the alternator (providing power to the inverter) was that unless the coach and start batteries were ganged together with the boost switch, the coach batteries were never fully charged at the end of the day.
This is because (with the boost switch off) the sense voltage for the alternator comes from the start batteries, which become fully charged quickly and in turn reduce the available amperage going to the coach batteries. This is in spite of having 850 watts of solar helping the alternator to charge the coach batteries, when the sun was shining.

I have taken a radical approach and currently have three 8D sealed batteries which do both coach power and engine start. This involved an extensive project of designing, testing and moving batteries and changing the location of inverter, converter, solar controller, amp hour shunt and wiring. I am releaved and overwhelmed by how successful this project has been, based on how well it works. This cannot be done without a lot of solar panels and strict power management.

I ran my previous P30 based, gas, motorhome the same way (no isolated start battery) for seven years.

Re: New Guy saying Hello...

Reply #14 – January 15, 2013, 06:03:52 pm

Welcome and congrats on the 320
Terry

Re: New Guy saying Hello...

Reply #15 – January 15, 2013, 07:17:49 pm

In my experience, Isolators drop about .5vdc through their internal diode. You will then get .5vdc less to your batteries than the alternators regulator is set to produce.

Combiners will do a good job of equalizing voltages between sets of batteries.

Better to have both banks, engine and house using the same technology...gells, AGM or wet cells.

External regulators are 'excellent'. Balmar products are my choice too as they are easy to program to whatever scenario you wish..., making it simple to to tweak in just what you want the alternator to do. Your batteries will love you for the effort!

Re: New Guy saying Hello...

Reply #16 – January 15, 2013, 07:30:32 pm

Slight correction:

DIODE-based isolators (not other kinds like solenoid-based isolators) cause a voltage drop of more than .5 VDC. It is turned into HEAT-- that's why all the fins. They dissipate the heat generated.

BUT, with an alternator voltage sense wire on the OUT side (chassis battery bank) of the diode-based isolator as Foretravel wired you system, your batteries see proper charge voltage. It is just that the alternator works a little harder and that "extra work" is turned into heat.

That said, I would not have a coach (and have not) with a diode-based isolator.

Completely agree on the smart regulators. Started with them on our sailboats 15 years ago.

Re: New Guy saying Hello...

Reply #17 – January 15, 2013, 10:29:04 pm

RE: **External regulators **are 'excellent'. Balmar products are my choice

Can Balmar external voltage regulators be used with non-Balmar alternators, like Prestolite Leece Neville?

I looked at their web site and product list, but I could not determine the answer.

Thanks

Re: New Guy saying Hello...

Reply #18 – January 15, 2013, 10:42:47 pm

Welcome, Squeezer.
From your posts it appears that you have enough experience to probably answer a few questions yourself. Glad to have you.

Re: New Guy saying Hello...

Reply #19 – January 16, 2013, 03:38:55 am

Quote from: BamaFan – January 15, 2013, 10:42:47 pm

Welcome, Squeezer.
From your posts it appears that you have enough experience to probably answer a few questions yourself. Glad to have you.

Thanks BamaFan... I am cursed with being a farm kid with an Engineering degree. Not an expert at anything but willing to learn.

Re: New Guy saying Hello...

Reply #20 – January 16, 2013, 07:22:49 am

Barry, I installed Balmar's best external regulator with their battery temperature sensor on my boat around 2000(not near the boat now, so cannnot confirm model #) but it has worked flawlessly ever since. The boat's house bank is (4) 8D Gells and since gells are both voltage and heat sensitive, regulation is extremely important. Sailing offshore and out of country, for safety and reliability, I felt Balmar was the best choice. I use a small case alternator(with a spare and spare parts), quite standard on boats and available everywhere, but most other brands are on many boats too, so my gut reaction is the Balmar regulators(now upgraded with extra features) will work with any alternator. However, I'd check with their tech support and that of the alternator manufacturer before any purchace.

Re: New Guy saying Hello...

Reply #21 – January 17, 2013, 10:55:45 am

Quote from: wolfe10 – January 15, 2013, 07:30:32 pm

Slight correction:

DIODE-based isolators (not other kinds like solenoid-based isolators) cause a voltage drop of more than .5 VDC. It is turned into HEAT-- that's why all the fins. They dissipate the heat generated.

BUT, with an alternator voltage sense wire on the OUT side (chassis battery bank) of the diode-based isolator as Foretravel wired you system, your batteries see proper charge voltage. It is just that the alternator works a little harder and that "extra work" is turned into heat.

That said, I would not have a coach (and have not) with a diode-based isolator.

Completely agree on the smart regulators. Started with them on our sailboats 15 years ago.

This is good to hear... Sensing on the battery side of the isolator takes that voltage drop out of the equation.

Taking this a step further. With the number of voltage sensing relays out there it probably would not be all that hard to have priority switching of not only the (high current) charge line but also the sense line...

Would look something like this:

Engine start-> Sense and charge chassis batteries.

(Chassis Batteries reach selected voltage)

Solenoid switches charge line to house batteries. (will switch back by default to chassis battery when necessary)

The above is easy with an off the shelf VSR.

(Pause for an hour of web searching....)

I like this one... HOW TO CHARGE AN AGM OR GELL BATTERY ALONG WITH A LEAD-ACID BATTERY

The REALLY cool feature is that there is a 2nd sense line that can be connected to the AGM house bank. Did not know this existed until just now as I have used the Blue Sea version in the past.

(Another pause...more research...)

OK this is a really really cool VSR. Wired in place of the isolator with the current voltage sensing line left on the (lead acid) chassis battery. It will combine the with the house battery when the chassis battery is charged. (Exactly what a VSR is designed to do...) The cool part about the Yandina model is it has a "Hi Voltage" sensing option that lets you connect a sense line to the house battery as well. I believe this provides an off the shelf solution for what I was trying to accomplish... (Just ordered the 160AMP model).

Cheers

Chris

Disclaimer: No affiliation with Yandina and everything up to this point is based on web research and not field testing... YMMV

Re: New Guy saying Hello...

Reply #22 – January 18, 2013, 10:24:27 am

Wyatt,

I had the impression from one of your previous postings that the alternator sensing voltage was from the starting batteries only.

Your comment I quote below suggests this is not the case when the boost switch is on. I'm thinking that means the sensing voltage is the voltage when the boost switch is on, which could be some average, or ?

Please clarify.

best, paul

PS> We expect to arrive at the Lemon rally Monday Jan 21st

"My experience with running the refer (Dometic 7832, absorption) from the alternator (providing power to the inverter) was that unless the coach and start batteries were ganged together with the boost switch, the coach batteries were never fully charged at the end of the day.
This is because (with the boost switch off) the sense voltage for the alternator comes from the start batteries, which become fully charged quickly and in turn reduce the available amperage going to the coach batteries. This is in spite of having 850 watts of solar helping the alternator to charge the coach batteries, when the sun was shining."

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