Battery charge

Alan · 08-18-2012, 08:37 AM

Just recently purchased a 1989 Sunline T1700. When I went to pick it up it was missing the battery. So I bought a deep cycle battery and everything seemed to work okay.....the jack, lights and etc. Plugged in the camper and all the outlets and fridge and ac worked. So, off to the lake we go. Plugged into the electric at the campsite and everything is good. After a few days the lights and the jack got dim and slow and by the time getting ready to go home, none of the 12 volts items worked, battery dead! When I am plugged into electric, should this not keep the battery charged? Is there a switch somewhere I don't know about? What am I missing?

Gene · 08-18-2012, 10:38 AM

Hi Alan, welcome to the forum.

When you are connected to shore power your converter should keep the battery charged. The converter in your 1989 Sunline is not the same as mine but most converters will have a fuse, about 30 amp, located on the converter someplace. Probably near the other smaller fuses that feed lights and stuff. That would be a place to start. If you charge the battery you can then use a cheap meter or test light to see if the 12 volts does in fact make it back to the converter. Many units have a fuse or self resetting breaker hidden up front near the battery so following the wiring back from the battery may locate that fuse/breaker.

**JohnB** · 08-18-2012, 08:48 PM

Hi Alan,

Welcome to Sunline Owners Club and congrats on your new camper.

Now to the battery, in addition to what Gene stated here is a quick way to tell if your power converter is doign anything, which it sounds like it is not.

Hopefully you have a digital volt meter or can have a buddy who has one do this.

Plug the camper into shore power. The converter should be on and creating power. Make sure your battery is hooked up. When the converter is actaully doing something, the voltage at the battery posts should be 13.25 volts DC or higher creating a float charge or higher an actual charge of 13.65 volts. If it is 12.7 volts or lower, the converter is not charging the battery at all and you are truley just running off the battery. A 100% state of charge is 12.7 VDC on a lead acid deep cycle battery.

Since all the lights and everything inside worked off a fresh charged battery, then the wiring and fuses from the battery to the inside fuse panel must be intact. However a fuse may be blown on the connecting between the converter and the 12 volt fuses buss bar.

It is also very possible your converter is just plain dead. If 120 VAC is going into it and 13.2 volts or higher is not coming out, then a fuse in the converter is blown if it has one or the circuit board is shot. Many of us, myself included have had to replace the converter. If you find you get to this stage of needing a new one, ask away as we have several post with the conversion.

Hope this helps

John

Alan · 08-19-2012, 11:42 AM

Wow! First of all thanks to all for the quick reply's!
Okay, I checked the battery voltage with out the camper plugged in. Read 12.6 VDC. So then, plugged the camper in and read again on the battery and guess what? 12.6 VDC. So I am guessing the battery is not charging when the camper is plugged in. Next went back to the converter box and opened up the lid on the front of it. Whole bunch of 15 amp fuses in there. So, I just checked them all and all were okay....darn! Got to probing around and reading voltages on the converter and read 12.6VDC. On the battery itself are two wires on the positive lead, one to the camper and the other to the jack, and one wire on the ground side. Said something about a fuse between the converter and the buss bar? Any ideas on this? Is it further inside the converter box? Right by the battery are a couple of inline fuses and also they check good. Kinda gott me puzzled. Is the converter itself maybe bad? Would think that those would last a long time.
Well, let me know if you have anymore ideas and again thanks for all your help!

1982 21RB · 08-19-2012, 01:45 PM

To check the converter I suggest that you unhook the battery with the AC Power plugged in and see if your interior lights work.

My 1982 Converter Manual states that the Battery Charger was an optional feature so I think it may be possible for the "charger module" to fail and the converter still work. That would not however explain why your battery died during your trip.. The interior lights in my trailer work without the battery installed.

mainah · 08-19-2012, 03:24 PM

The outlet above the fridge is where the converter picks up power (I have a T1700) so you might try a lamp or some in that outlet to see if it works while you are plugged in. There are two power outputs in the converter one to charge the battery the other to provide power for your 12 volt stuff lights, water pump etc. so it sounds like you either have no power to the converter or it's toes up if you have lost both.

**JohnB** · 08-19-2012, 04:59 PM

Alan,

Your 12.6 volts confirms there is no charge going back into the battery. And the reason your light on the camping trip went dim is, you drained the battery.

This now points to the converter system itself. And as far as age, if the unit is original and it is an 89 unit, 22 to 23 years is an amount of time.... Mine was replaced after 4 years of use due to bad fan controls and the lack of new parts.

And I'm sure some are still working 30 year later. In my case the fan controls where notorious for going bad on my brand. Yours may be just convection heat dissipation.

I do not know your brand converter, if there is any kind of wiring schematic we can figure it out or if someone else has that same model can help. What brand and model is it? Pic help too. On some converters they are fused on the converter itself. Sometime on the 120 VAC input and sometimes on the 12 VDC output. That was the fuse I was referring to.

At this stage your going to need to figure out if 120 VAC is going to the converter and if 12 VDC is coming out. And "some" of the older converters needed a battery in the system to work properly. Not all of them but some brand did.

Hope this helps, good luck.

John

Alan · 08-26-2012, 04:59 AM

Hello everyone,
Thanks to all for all your help and answers. I finally fixed it! The hardest part was getting the converter out and back in. Turns out there is a 6.5 slow blow fuse inside the converter. So I drilled a hole in the top of the box and installed a circuit breaker instead. Connected the battery and plugged her in and got 13.2 VDC on the battery and then disconnected the battery and the lights still stayed on....yippee!
Put her all back together and ready to roll out.
See ya all soon and again thank for all your help.

**JohnB** · 08-29-2012, 07:20 PM

Alan,

Glad you have it going now. Great!! and thanks for reporting back. This helps others finding your post on the fix that may help them.

Happy camping

John