Good morning all,
I emailed Jayco and they said they no longer have have my "prints" in thier system. I guess my 2010 is too old. Darn!
I know it's a long shot, but does anyone have a schematic for this motorhome? Or a simular motor home you could share?
If anyone is interested, I plan to upgrade the old group 27 lead acid battery to a LiFePO4. We plan to do a some brief boon docking this fall, about 2 or 3 night's at a time and would like to run the furnace overnight. Yesterday I ordered a 100 ah SOK which I think will get us through a nite or two with recharging via the generator during the day. However, I'm concerned the battery will not start the generator or will over stress the battery during starting.
It was suggested I keep a Lead Acid Battery for starting the generator and separately use the Lithium battery for DC coach load, hence the need for the schematic...
Sigh, old guys with old motorhomes...
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2010 Jayco Greyhawk 31 FK
My Other RV is a Vans RV-8
This schematic is for a 2013 GreyHawk however it seems to be correct for my 2010 GreyHawk and likely yours as well. While helpful, there isn't as much detail as I prefer.
Also, I have a 100ah lifepo4 in mine now and I plan to do some more upgrades as I have more lifepo4 capacity and solar to install one day, in any case keep in mind that your generator engine isn't all the big, more like a riding lawnmower engine, point being, I haven't had any issues starting the generator with my 100ah lifepo4 and I suspect you will not either. If you did have an issue, you (with a helper) could always push and hold the aux start button on the lower left of the dash and then start the generator (or start the big engine as that will connect the two batteries (coach and chassis)), that way you could get the chassis battery to help with starting the generator. In fact, I have a toggle switch now to replace the push button aux start (emergency start many call it) so I can turn it on without having to be there holding it. ~CA
I haven't had any issues starting the generator with my 100ah lifepo4 and I suspect you will not either. If you did have an issue, you (with a helper) could always push and hold the aux start button on the lower left of the dash and then start the generator (or start the big engine as that will connect the two batteries (coach and chassis)), that way you could get the chassis battery to help with starting the generator. ~CA
Thanks craigav for the schematic and your experience. This is indeed good news. I would much rather install the lithium without serious modification. I suspect I'll install a DC to DC charger between the engine alternator and new battery. Plus a new lithium friendly converter charger. But that is a lot simpler than my prior plans.
Again, Thanks!
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2010 Jayco Greyhawk 31 FK
My Other RV is a Vans RV-8
Thanks craigav for the schematic and your experience. This is indeed good news. I would much rather install the lithium without serious modification. I suspect I'll install a DC to DC charger between the engine alternator and new battery. Plus a new lithium friendly converter charger. But that is a lot simpler than my prior plans.
Again, Thanks!
Here are my thoughts to keep things simple. If you leave the converter as it is, it will still charge the Lifepo4 battery(s) however at a lower voltage which will not harm the battery. My plans are and I have already purchased what I need, just haven't had time, but my plans are to use in addition the following power supply which will charge the lifepo4 quicker (I plan to run about 2~300ah of lifepo4). This power converter comes in lower amperage models, but you need to make sure that the one you order (if you order) has the 2 screw holes in the side as you see on this one. That allows you to adjust the voltage to whatever you choose (14.5).
My plan is to keep the current converter in place as it is best not to keep a lifepo4 battery fully charged when not needed anyway. So my plan is to charge it to 100% whenever I plan to boondock and at other times keep it at the lower voltage charge (13.8v) that my converter already provides.
In addition, I purchased the 40a Renogy dc2dc charger. I have yet to install it though however my plans are to install it next to (or near) the charge relay which is directly in front of the steering wheel, under the hood on the back firewall. What I think I will do is disconnect the output cable of the relay and connect the input of the dc2dc charger to that terminal and the output of the charger to the cable that I removed. I will either use a switch to turn the charger on and off, or use the connection already on the relay to trigger the charger.
I will add, that without doing anything other than replacing the lead acid battery with the lifepo4, that everything works great as that is my current setup. I suspect though that the lifepo4 never gets a full charge though and although that is debatable as from my research it appears that with enough time that a lifepo4 will still come up to 100% charge even at the lower charge voltage of 13.8 volts that my converter already provides. I still connect and charge the battery with the powermax powersupply prior to boondocking though to be sure the lifepo4 is at 100% although it seems to get to 100% very quickly so I suspect it does get fully charged even at the lower voltage, just that it is a bit slower when the battery is low.
With all that in mind, and when time allows, I plan to add ~200ah more lifepo4, solar, dc2dc charger, and the powermax power supply. I already have the items to install. I suppose one reason I haven't done so already is that simply swapping the lead acid battery for the lifepo4 seems to do all I need for now. ~CA
Craigav,
Thanks for your comments. I think I will initially go with the old 45 amp converter / charger and no DC to DC charger for now. The old lead acid battery was in a tray exposed to the elements so I plan to install the SOK lithium battery in the storage compartment adjacent.
I'm a bit concerned about stressing my alternator without a dc to dc charger. I'll avoid charging the lithium battery with the alternator when it's in a low charge state.
Thanks again for sharing your experience. I feel much better about this change now.
JP
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2010 Jayco Greyhawk 31 FK
My Other RV is a Vans RV-8
Craigav,
Thanks for your comments. I think I will initially go with the old 45 amp converter / charger and no DC to DC charger for now. The old lead acid battery was in a tray exposed to the elements so I plan to install the SOK lithium battery in the storage compartment adjacent.
I'm a bit concerned about stressing my alternator without a dc to dc charger. I'll avoid charging the lithium battery with the alternator when it's in a low charge state.
Thanks again for sharing your experience. I feel much better about this change now.
JP
I agree with going with the DC2DC charger when you can. That is my plan as well. If you look at the schematic there is an 80a breaker in the circuit so that would limit the alternator to an 80a charge rate. I purchased the Renogy 40 amp DC2DC charger and just need to install it. I have attached a schematical drawing of how I plan to wire it. I plan to use a single pole / double throw / center off, switch on the dash, likely where the 12v power outlet is below the radio. This will allow me to engage the existing relay and bypass the dc2dc charger, or the opposite engaging the dc2dc charger bypassing (leaving turned off) the existing relay, or doing neither with the center off position. That way, I can wait a few minutes after getting on the road before turning on the dc2dc charger, and connecting the input of the spdt switch to the existing relay trigger allows me to keep the existing emergency start switch operative if\when needed.
This is my current thought and I am not sure of where I will physically install the dc2dc charger yet. All subject to change if I came up with a reason to do it differently (such as I will add fuses for the input\output of the charger not shown in the drawing). ~CA
I never installed the DC to DC charger. We have taken a couple long trips and the alternator has performed well. The LiFePo charge/discharge gauge has never indicated high amps from my alternator when charging the 100 ampHr SOK LiFePo. It starts my 4000 watt generator just fine also. So far so good!
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2010 Jayco Greyhawk 31 FK
My Other RV is a Vans RV-8
Interested Craigav, did you ever install dc2dc and switch?
Never have, although I have everything I need to do this, just that I haven't had the time to do this and I haven't gone boondocking this year.
However, looking at what I posted earlier, the diagram still looks to me to be the very best way to go with a Class C. The only thing I would change perhaps looking at it now, is that an 8awg cable for the output of the dc2dc charger would be fine. I likely will move forward sometime later this year, seeing how I have everything I need purchased already. ~CA
I never installed the DC to DC charger. We have taken a couple long trips and the alternator has performed well. The LiFePo charge/discharge gauge has never indicated high amps from my alternator when charging the 100 ampHr SOK LiFePo. It starts my 4000 watt generator just fine also. So far so good!
I am just running a single 100a LifePo4 as well at this time and w/o the dc2dc charger as you are and I also can start the generator just fine.
While you most often hear about needing a dc2dc charger to save the alternator, that really isn't a huge concern on our Class C's. The reason I say this is that if you look at the schematic I shared, you will also see that there are 2 x 80a breakers (self resetting) inline with the charge circuit, which will prevent the alternator from being too overwhelmed (>80a) with charging the coach batteries and especially in the daytime with little other 12v loads running. (fyi: I am not sure all Class C's, in particular newer models, use 80a breakers, 100a would be more concerning for me).
Keep in mind though that these self-resetting breakers could trip back and forth many times with a very low coach LifePo4 battery(s) which is ok, but doing so will shorten the life of the breakers (maybe carry a couple spares).
The other reason for the dc2dc charger though, and perhaps more of value for when boondocking is with the higher charge voltage the dc2dc charger provides which will fully charge the LifePo4 battery(s) where without it, the charge voltage is a little less and the alternator will likely never fully charge a LifePo4, at least not without a lot of time. In any case, not fully charging a LifePo4 causes no harm, in fact reports are that Lifepo4 batteries will last longer when not fully charged, especially if the battery remains fully charged for long periods of time (as in storage perhaps). ~CA
Craig, did you finish the install? Any issues with the schematic and expected working results? I like the idea of keeping both the old charging method and adding new for redundancy as well as allowing proper charging voltages on lifep04.
Craig, did you finish the install? Any issues with the schematic and expected working results? I like the idea of keeping both the old charging method and adding new for redundancy as well as allowing proper charging voltages on lifep04.
It will likely be this spring before I have an opportunity to move forward on this and a few other projects\updates on my RV. I looked over the schematic again and I don't see any concerns. One thing I have to check out further is to determine where to mount the charger and the switch I plan to use. There is a spot on the dash next to the 12v outlet I may use for the switch and hopefully there is enough room near the solenoid to mount the charger. ~CA
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