Battery Time

dtstanton · 09-28-2014, 10:34 AM

Still running on the 1350's battery that the PO had in 'er, it finally gave up the ghost. Found some low cells, filled with distilled water and did an overnight charge - if you can call it that. It came out with about 9 volts this morning, one cell off the scale below 1100 sg - almost to being freezable at 32 deg., and two others were below marginal. (I use a refractometer, not the float type.) The battery was fairly warm, and most of the cells showed at least some activity. It's an Interstate SRM-24 that's been on her since January of 2009. Yep, probably time to replace it anyway.

I also found a blown fuse going to the BATT terminal of the 7-way that I'll have to replace - after finding out why it blew. Don't want to screw up our Yukon's system, after all. Don't know how long it's been blown. Could it have blown if someone hooked up the 7-way while it was hooked up to shore power? I'm a stickler for not doing that, BTW.

Is there anything I should make it a point to check on the charger/converter before I put it in service with a new battery? I checked when I found the problem and it's putting out about 14.4v - if overnight charging didn't change that. Didn't check this morning. I will be getting some anti-corrosion battery stuff to coat the terminals/connections with when I install it.

I'm open to any tips and suggestions. Now......off to get a battery! Camping next weekend in Caprock Canyons, where the bison are freely roaming throughout now.

Gene · 09-28-2014, 06:08 PM

Quote:

Originally Posted by dtstanton

.... Could it have blown if someone hooked up the 7-way while it was hooked up to shore power? ......

A definate maybe.

Quote:

Originally Posted by dtstanton

.... .. I'm a stickler for not doing that, BTW.....

That makes 2 of us.

Quote:

Originally Posted by dtstanton

.... Is there anything I should make it a point to check on the charger/converter before I put it in service with a new battery? I checked when I found the problem and it's putting out about 14.4v - if overnight charging didn't change that. ...

If the converter is putting out 14.4 while charging a low battery you should be good. However after charging it should drop back to the 13.6 range or even 13.2 so you don't cook the battery.

dtstanton · 09-28-2014, 07:47 PM

Thanks, Gene. When I put the new battery in, it was reading 12.5v. When I plugged it in, it went to about 13.5 and hovered around that and 13.3 - kind of fluctuating by a tenth or two. Looks good to me for a fully charged battery.

Gene · 09-28-2014, 08:01 PM

Those numbers are right where they should be.

Enjoy your trip to Caprock Canyons.

dtstanton · 09-29-2014, 10:48 AM

It'll be tough, but I'll try.

**JohnB** · 09-30-2014, 05:33 AM

Dale,

A quick note to add, your vintage GM has the battery line in the 7 wire plug live all the time even when the ignition is off. When I switched to the Blue Oval from the Bow tie... Ford puts a relay in the charge circuit so you do not drain the battery or back feed it.

My Suburban or prior Tahoe would let you kill the truck battery if left plugged in with the ignigtion off. A good and bad feature.

JerryJ · 09-30-2014, 07:11 AM

Most of us are familiar with the obvious. Batteries are typically good for about 6, or so, years. We have all seen batteries crap out much earlier than that, not to mention those that last longer. I replaced my Explorer battery last year and it was 11 years old. It does happen in all directions.

As we know, batteries have an internal resistance and will "self drain" on their own. One thing I do for long term storage is plug the TT in for an over night, maybe a day or two for shore power.
If lead acid, flooded batteries are allowed to drain too low, to almost dead and if you live in a colder climate, the water/acid/electrolyte can easily freeze. This freezing permits the plates to warp, warping will make the plates touch each other and create internal shorts.

One thing I try to do during the winter is to plug in the TT about every 2 weeks to once a month, pending how cold it is outside.

A decent charging rate is anywhere between 13.8 to 14.3 VDC.

The charging voltage is called dynamic charge (the actual charging voltage)
The float voltage is called static charge when the battery is at rest, no charge and no draw.
They recommend that after you finish charging you battery to disconnect cable, wait 30 minutes for the voltage to stabilize and then check the static charge. this will show you the battery's actual health. RV House Battery: How to keep it charged
In this article they also suggest to never let a deep cycle battery not to go below its 50% charge. I rigged up a simple automotive volt-meter seen on after market applications for dash mounts. I have it wired up to a cigarette lighter plug-in and only plug it after any extended use.
I could easily mount it but it was not a factory install and in the spirit of keep my T-1350 factory original, it remains a plug-in.
I also have a second deep cycle battery hooked up in parallel and because I can hide it under a bed, it's none permanent. NOTE placing any battery inside a TT is not the greatest idea but it's also in one of those marine battery boxes. It's still not safe but I do keep an eye on it.

BTW the use of a hydrometer allows to check the SG of individual cells, another excellent test. Another test you can do is to perform a load test on the battery. So, there are several ways to check and keep your battery(s) in tip-top shape

Wannabes · 09-30-2014, 03:52 PM

Quote:

Originally Posted by JerryJ

BTW the use of a hydrometer allows to check the SG of individual cells, another excellent test. Another test you can do is to perform a load test on the battery. So, there are several ways to check and keep your battery(s) in tip-top shape

We're assuming that 'SG,' also mentioned by Dale, stands for 'specific gravity'?

Thanks, JohnB, for your informative tip-in. We were going to ask, Why is it not good to connect the 7-pin to the TV whilst connected to shore power, but your reply explains the reason.

dtstanton · 09-30-2014, 04:34 PM

Quote:

Originally Posted by JohnB

Dale,

A quick note to add, your vintage GM has the battery line in the 7 wire plug live all the time even when the ignition is off. When I switched to the Blue Oval from the Bow tie... Ford puts a relay in the charge circuit so you do not drain the battery or back feed it.

My Suburban or prior Tahoe would let you kill the truck battery if left plugged in with the ignigtion off. A good and bad feature.

That's good to know. Thanks, John!

dtstanton · 09-30-2014, 04:40 PM

Jerry, I would never charge a lead acid battery inside a TT. Trust me. They create one helluvan explosion with a very small spark/arc.

I only use a properly calibrated refractometer instead of a hydrometer. I've seen too many errors with hydros.

Freezing will also split the case.

dtstanton · 09-30-2014, 04:43 PM

BTW, you can't see or smell the hydrogen. Don't turn your TT into the Hindenburg.

**JohnB** · 09-30-2014, 06:00 PM

Quote:

Originally Posted by Wannabes

Thanks, JohnB, for your informative tip-in. We were going to ask, Why is it not good to connect the 7-pin to the TV whilst connected to shore power, but your reply explains the reason.

GM's use to, may still do, have a direct connection from the 7 wire to the battery with only a fuse in line.

Ford and I think Toyota have a relay in most cases.

So yes, if you do not have a relay in the truck circuit that cuts off the power to the 7 wire, using the camper with no shore line power hooked up can drain both the camper battery and the truck battery. This is not a 5 minute or 10 minutes issue, but more hours worth pulling a lot of current like running the furnace in cold weather.

Gene · 09-30-2014, 06:09 PM

Quote:

Originally Posted by JohnB

..Ford and I think Toyota have a relay in most cases. ...

Just to add to the list, my 2008 4Runner has a relay as did my 2000 Jeep GC.

JerryJ · 09-30-2014, 06:49 PM

Another thing to consider, depending how creative you feel.
I have a Koolatron and it has an in-line Battery Saver, so that when you're traveling and decided to stop at a restaurant or Walmart run or a sight-seeing venture you can leave your Koolatron running with engine off. The Battery Saver (TM) will shut down at 11VDC before it kills your battery.
My new 2,000 watt AC inverter has the same feature.

Maybe, just maybe you can grab an after market Battery Saver and hook it up in series from the tow vehicle to your TT. What ever current you think you might require during towing would determine what size unit you need.

Because this is hooked up in series you could either hard-wire in the TT or at the TV (tow vehicle).. The other concept would be to use a battery isolator, however that could a deeper hook-up arrangement and not so practical for your set up.

Dtstanton> I thought about that many a time and considering moving it outside on the tongue. With an AGM it would not be an issue but flooded can allow kaboomkies.

dtstanton · 09-30-2014, 07:21 PM

We have it easy. We don't use the T-1350's 12v while traveling - just the exterior vehicle lights.