Community Forums

mytime · 01-10-2017, 07:02 PM

I learned when I was having the problem, that some folks had switched the generator from the house batteries to the coach batteries.

**CountryFit** · 01-10-2017, 07:48 PM

Quote:

Originally Posted by mytime

I learned when I was having the problem, that some folks had switched the generator from the house batteries to the coach batteries.

hmmm... "from...house batteries to the coach batteries..." aren't the two the same?

Smitty77 · 01-10-2017, 10:14 PM

Might be worth the effort to try adding a stand alone battery and temporally adding it's power to the starter. (Along with he existing power supply.) Then if the generator still turns over slowly, you know you should be double checking that the starter is healthy.

What throws me, is the same wire and route of power from the battery to the generator starter - seems to carrie enough juice to allow the generator to kick over faster, when the engine is running. (If I read what you said correctly?)

So that seems to point at two conditions that I can think of:

1) Butch is right (And yes, I agree he is very knowledgeable on CC's!), and the cable was undersized on some models.

2) As mentioned by others, you have a ground problem somewhere in the power flow path.

Either condition, with the stepped up juice of the engine generator in the mix, gooses enough power thru to the generator starter.

A cleaning of the ground points along the path, for sure would not hurt. And heck, many solve the problem.

If the grounds all check out OK. Then adding a second battery up front for sure would not hurt. I'd probably go with an AGM, and suspect a Grp 27 would cover you, and for sure a Grp 31. AGM due to install and forget.

You could also go KISS on the charging of this battery maybe adding a Solar power charger. Something like the 15W (Probably overkill) Battery Tender.

021-1165

And as mentioned, adding in a charge when the generator is running, sure would not hurt either.

I know you always come back and share your final outcome - please do so on this one, as it sounds like a few others have had generator starting problems too.

Best,
Smitty

BrianGlenn · 01-11-2017, 04:10 AM

Smitty, I have the similar problem in my 2007 Allure. Gen starts off the house (coach) batteries.

Off course the gen gets started when I am boon docking and the house batteries are lower than full state of charge (12.8ish). Long run of undersized starter wire from back of coach to front with starter current has voltage drop to even lower (I never have measured) preventing the QD10kW from turning over fast enough to fire or heat to the glow plugs to ignite (not sure which is the primary cause of no start condition). Using boost when my chassis batteries are full state helps, however starting the coach raises voltage to 14ish from the engine alternator and the increased voltage starts the gen.

I have cleaned the terminals on the back of the gen and added electrical conducting grease and it helped a bit. Upsizing wires to reduce voltage drop at starting current or adding a higher voltage source near the generator are two solutions. Another one that I was considering was to add another parallel starter wire(s) from rear batteries to front generator lug(s). I have not finished my research to know if I could get away with just a positive wire run and connect a single ground wire at front, or I need a parallel ground wire all the way back to the existing ground.

Somehow I have a feeling I would only need a single parallel positive wire and could rely on the existing ground wire size. It is a voltage drop issue and not an over current issue.

Can't sleep tonight so was probably a little more verbose in this posting, apologies in advance.

Brian

mytime · 01-11-2017, 05:04 AM

I spent numerous hours dealing with this issue, I talked to the local Kubota dealer (tech), I made numerous post on here and other forums, back in 2012,3013.. I used a jumper battery to my starter, even removed the wires from the starter, but at the end of the day the issue was the same, long, too small a cable (around 50 feet, with the slack needed for the slide out.), coupled with batteries that need to be charged. (Reason for starting the generator in the first place). By far the best solution was to install a stand alone battery , now how are you gonna keep it charged, same as CC did with your chassis batteries, trickle charger, when your chassis batteries are charging, your generator battery is charging. I have had in this way since 2013, not one time has it not fired right up. Fix cost less than 300 bucks., about the same as a good steak dinner.!!

mytime · 01-11-2017, 05:24 AM

CC, had some good technical people, but this issue was not one of their best brain storms.
50 feet of #2 cable, (that's my thought ).
Maybe it was over sight when they used the 10kw generator, in the place where some had the 8kw (residential fridge ). The Kubota engine in the 10kw needs super amps to start that bugger., dead house batteries will not do the job!!

YC1 · 01-11-2017, 06:32 AM

Quote:

Originally Posted by CountryFit

i think just a single diode cost less than $10 will do the job. look at #3 post.
i am using a big diode with 250a pass-through on one of my mods, no problem.

A single diode would work of course but using a diode isolator gives you posts to connect to and a handy way to mount it. They are relatively inexpensive too.

smlranger · 01-11-2017, 06:53 AM

Quote:

Originally Posted by mytime

CC, had some good technical people, but this issue was not one of their best brain storms.
50 feet of #2 cable, (that's my thought ).
Maybe it was over sight when they used the 10kw generator, in the place where some had the 8kw (residential fridge ). The Kubota engine in the 10kw needs super amps to start that bugger., dead house batteries will not do the job!!

Butch told me that if the house batteries are below 12.5 V, it will likely not start. It was a known issue.

Do you by chance have a pic of battery placement? I am thinking it would best fit behind the clip right next to the front of the generator. However, there is a steel cross member that may create a clearance issue if the battery box is too tall.

I believe that Optima battery you used is not very tall.

lonfu · 01-11-2017, 08:15 AM

Quote:

Originally Posted by mytime

Several issues with adding batteries together in a bank, they. All should be the exact age, mfg, and series, purchased at the same time, there are few exceptions., plus you draw from one you draw from all, your issue would not change, the additional battery would be at the same state of charge as your existing batteries. You cannot use the existing cable in no way to connect the new battery. The new battery will be a stand alone battery, it does not know the other batteries. The trickle charger is the bridge between the separated batteries.
Works exactly the same as your house batteries and coach batteries, you have a trickle charger there.
I think I used a 5amp, 3 wire.
Clear as mud right.

I disagree with you on the combining of batteries. Yes, you have to be careful not to put an atv battery in with an 8 d battery. As far as age goes, as I have said many times, buy a stupid "battery load tester" it is the only way to find out the try condition of your battery. It is why the shops all over the world use them..... If you have a couple of batts that test about the same condition as far as load go, you can put them in the same charging circuit and it won't hurt them. but if you try to put a 100 amp batt with a 800 batt you are just asking for troubles. I would call this common sense. Since I've done it when I was young and poor, I know it can be done. When I was young I would test a batt and give some smuck $5 for it, more than a shop would and use the thing until it wouldn't hold a charge. The trick is not the amps, but the physical dimension and will it fit in your coach. They all charge by measuring voltage, you can over charge if you get a one dead batt in a set of say 4. Seen this happen most often in 6 volt systems, one 6 volt goes bad and then the batt in the series circuit with it gets over charged. the trick is catch it in time......One of the problems with 6 volt systems is that the "following" batt doesn't seem to charge the same as the "lead" batt. when you load test a set of 6 v's in series, the following batt, (fartherest away from the charger) always show slightly lower load rating. That is why if you can fit them, I always recommend 12v's instead the WW1 tech of 6v's.

Yes, it is true, if you use a brand new batt with a really old batt that the new batt will ratchet down in capacity to the lessor battery, but..... then there is the $$$$$.... and how long you need it to last for.....some times it is worth it.....

mytime · 01-11-2017, 03:58 PM

Ok, I'll agree that you can use batteries of different origin and mix match a bank, but in the motorhome ownership manual it is understood that high tech equipment is very delicate, so when I have a problem , I try hard to fix it the first time, not so much for myself, but maybe the poor sole that gonna want this monster when I'm tired of it!!