ONAN/ Cummins EVP 5500 generator trickle charge question

[MatthewS]

Hi All,

I have a Voltage toy hauler with an ONAN 5500 evp generator. Does this generator run only off the house battery, or does it have a battery of its own for starting? My unit was getting service done and the house battery is flat, and I am wondering if the generator has a battery that needs some charge or does simply charging up the house battery solve this? Thanks for any feedback

Additionally, do you all charge up you house battery all the way before a trip or is it better to let the truck charge it while towing?

we have been out a lot the last couple years and had a bad converter all along so our way of doing things was to let the battery fill up while charging due to constant battery issues the first couple years, but I think we are ok now.

Thanks for any feedback

[lcv800]

No separate battery. Charge up all the way. From what I've been told, the amount of charge due to wiring, etc. that tow vehicle puts out is pretty small.
Rusty

[dsol]

I would say topping off your batteries frequently is a good idea but you don’t want to leave a constant charge on them for too long as that can reduce capacity by essentially boiling out water. Obviously, you don’t want them to go flat either as that can cause sulfates to form that reduce capacity.

If I will be dry camping I always charge the batteries for 12-24 hours before going out then don’t worry. If camping with shore power I don’t worry because after a few days of constant power they are topped off anyway.

And like the post above says there is no generator battery so if the house batteries go dead you will not be able to start the generator, which by the way should be ran monthly with a load on it to make sure it stays in good shape too.

[MatthewS]

Thank you for the replies. I have had my trailer out on 20+ trips over the last couple years but now I am fine tuning. We fall into the category of those who bought at the beginning of covid but we are hooked now. Thanks for all your patience and support. This forum is a good thing.

When I took the 5th wheel in for service the dealer was trying to buy it back for more than we paid. Can you believe how expensive they are in 2022?

[franktafl]

not sure I would venture anywhere without my battery fully charged. Too many things depend on 12 volts, landing gear in case you need to unhook, slides in case you need them, heater,etc. Your truck will, at best, only give the battery a partial charge since the wire is mostly 12 - 14 AWG and not fully dependent on charging a battery without it being hooked up for many hours (trickly charge at best).

I previously placed a solar panel on the top of my RV and a solar charger regulator on the system so I could maintain a fully charged battery since the vampire loads will deplete a battery in just a few days, even if the battery switch is in the off position. 100 watts should be enough to maintain those loads and keep your battery topped off.

[MatthewS]

I agree on the battery being fully charged or close to it prior to departure. I am just a little cautious now due to the fact that our converter was bad, so it blew up two batteries. I am very careful to make sure the battery has appropriate amounts of distilled water and charge going forward and carry a backup new battery.

I will say the dealer I purchased it from, Richardsons RV in Ca., was great resolving all warranty stuff

[franktafl]

Wouldn't you rather find out your converter is bad BEFORE you start you trip?

[MatthewS]

Good point.

I simply thought the fact that it was losing charge was somewhat normal. We camp mostly at 5O amp sites and plug in to the site power before lowering the landing gear.

The battery/converter issue was progressive I believe. We shall see if its resolved, on the battery tender now charging.

I am not pretending to know everything and I feel even in two years of many camping trips its good to be teachable so I appreciate the feedback.

[persistent]

Lead acid batteries need to be stored fully charged. Fully charged means 14 to 18 hours on a high quality charger. Driving rarely provides 14 hours of charging.

As posted above, starting out fully charged is the best for long battery service life.

Also, the quality of connections between tow vehicle and TT vary a lot. Often they don't charge as fast as you might expect.

[MatthewS]

I have two lead acid sealed Interstate batteries now. Previously I was on 1 Die Hard battery, which is how I took delivery and I believe it was running low on water and I wasn't storing it on a maintainer. This is what likely caused my problems, now I have two sealed interstates on maintainer run in parallel.

[MatthewS]

I thought I had my problems with my electrical system restored to normal. Unfortunately, this is not the case.

I was previously having trouble with my batteries holding charge overnight when unplugged and burning out because they are lead acid and running flat.

My Voltage is under warranty, so the service advisor replaced a couple 12v batteries and had dutchmen send out a new convertor. I believe the converter was replaced because the batteries were not holding charge overnight and were not getting a proper charge.

So, I get the trailer back a couple days ago and put in 1 new battery (tested it with a voltage meter before install) to see what happens once it is installed correctly overnight with a battery tender on it. Power switch to the unit is off, trailer not plugged in to any outlets via extension cord. I didn't install the second battery in parallel yet because I didn't want to burn out 2 batteries, although I had it ready to connect in parallel but at the last minute thought against it.

I went out this morning to wire up the second 12V and checked the first battery that had been on the battery tender wired to the trailer, and it was flat.

I am thinking something is wrong with my disconnect switch on the trailer causing every battery to drain every night even when in the off position and my service advisor is not being proactive at this point to inspect my entire system.


Does anyone have any ideas as to what my problem is?


thanks in advance

[dsol]

There are a few items that bypass the disconnect. I know my landing gear and entire 6 point leveling system work regardless of the disconnect switch.

Clearly, you have something putting a heavy drain on your batteries.

You can put a multimeter in line with your positive terminal and the cable and measure the current draw to see what is going on.

[persistent]

Clearly your "battery disconnect" is not working to disconnect the battery. A true disconnect will act the same as a battery cable not being attached. Owners sometimes install them after market near the battery bank.

Battery disconnects typically supplied by battery manufacturers do not disconnect everything. Why is a matter of speculation. It may be safety devices remain connected. It may be computer controlled energy management systems remain connected.

Battery disconnect systems can fail.

Battery disconnects systems can be inadvertently bypassed when various custom changes are made by dealers and owners. Adding a power tongue jack or an entertainment system or anything can do it. All can fail and continue to draw power.

Power wires run helter skelter through the underbelly can have abraded wire that begins to short power to ground and ends by blowing fuses or making smoke.

Measure and trace. Don't wait over night to see if it works. If it runs down in 8 hours, you can measure significant voltage drop at the battery terminals in 2 hours.

Fully charge batteries measure 12.7 volts or above.
Half discharged batteries measure 12.1 volts or below.
Flooded cell batteries should maintain a full 12.7 volts for months if disconnected.

[MatthewS]

Thank you Persistant.

I haven't performed any "after-market" modifications but the wiring to my disconnect and the disconnect itself is now suspicious.

[Ovalvw]

I have Found our voltage has a lot of vampires
Sucking juice even with switch off
If I know it’s going to be sitting more than
2 weeks I disconnect the battery cable
At the battery. I’ve searched for the vampires!
No luck That’s my cure. Not to
Complex but effective
All our best central Florida

[MatthewS]

Yeah, I guess our solution the last couple years was to be constantly camping, and at 50 amp sites. I'm interested in dry camping more as the campsites and fuel costs are getting pretty high. Gotta fix this battery issue.

If I learn anything this week I will report back.

[jjrider]

I acquired a Battery Tender solar charger that I set out in the sun, it keeps both rv and motorcycle batteries charged. I made a stand for it out of pvc tubing.

[MatthewS]

Good afternoon,

just an update. It looks like we fixed our trailers electrical issue. Apparently, there was a minor wiring mishap on the disconnect switch that occurred during production. I believe we found and resolved the problem, and in the meantime also found a decent mobile rv service tech. if he fixed it the fee was a bargain.

I will report back in a week, thanks again for all input.

_ Matthew

[MatthewS]

Our problem was definitely the disconnect switch. Had it rewired by a professional and our trailer functioned perfectly on our last trip.