What do the letters mean?

Dumb question--what do the letters mean on the battery indicator? I am guessing C is charging, and L is low, what are F? and G?

I cannot tell if the battery is charging. We have only camped one night each of the two times out with the new 3124KB. Should the battery normally charge overnight when hooked to shore power? (The battery was installed at the dealer --there was not one on the TM when it arrived from the factory.) This morning when plugged in to shore power, all four of the lights on the battery indicator on the panel were lit up. When I unplugged from power, three lights were lit up. Does that mean it is fully charged? I wanted to test the battery so I turned the refrigerator on DC (it was already cold). After thirty minutes only the L light was on. After reading some more here I see that I shouldn't have run the refrigerator on DC unless towing. (I'll never forget and do that again! -example of learning from your mistakes. ) Would this have drained the battery that fast? I hope next time with just a few lights and water pump it will last at least a day or two!

We're about to leave on a two week trip to Big Bend National Park and I understand most of the sites have no hookups. I would hate to leave Alabama with a battery that isn't working correctly. (I did look in the box and they installed a deep cycle marine battery--the positive connector has the black wire with another added red wire that has "30 amp" written on it and the white wire goes to the negative connector.) Is this the fuse that could possibly be blown (read about it elsewhere on this board)? Is it the same type fuse that is in the fuse box inside the TM? I have some extras like those that are 30 amp. Or is this one a totally different kind?

One more question and I'll definitely be over my limit--some of the other posts talked about the breakaway switch affecting battery usage? I could not understand whether having it unplugged caused battery drain or having it plugged in causes battery drain. Could someone clarify? I'm a total novice and know nothing about batteries (among other things) except what I have read here. Thank goodness I had this as a reference! No telling how many costly errors I would have already made. My husband is in poor health and I am trying to take care of everything. The learning curve has been steep, to say the least!


Thanks for your help.

Kat

Kat

I'll tackle the questions I can answer and leave the others for the pros.

The charging system reads C for charging as you suspected. I don't find this device to be described in the owners manual. I get the highest light on (F) when charging. The next light when well charged without 110V hooked up or operating from battery. The two lower lights are for lower states of charge. (I would like to have a voltmeter on this line myself).

Frankly, the charging system is pretty wimpy. It can take 40 hours or even more to charge a dead battery to 90%. Your refrig draws 10 or 12Amps and for half hour that would be 5 or 6 Amp Hours. My battery (factory) is 75 Amp Hour, so a charged battery should run 5 or 6 hours with no other loads. I suspect your battery didn't get charged fully on the way to the campground. There is so much voltage drop in the TM and TV that the TM battery actually supplies part of the current the refrig draws while on the road.... that means the battery is discharging rather than charging while towing. Your refrig (as you stated) should be run from either 110V or propane whenever possible. My plan is to get the refrig cold and turn it off while on the road. That is the only way I can figure to keep my battery charged. Put some blue ice in it. By the way, it is unsafe to run the refrig on propane on the road. It would be really bad to have a fuel spill at a gas stop while operating on propane.

No, your fuse isn't blown. If it were, you wouldn't get any lights, pump or other power in camp (110V assumed disconnected). The fuse back near the battery passes both charging and discharging current, so if you get lights from the battery (no 110V plugin or operating TV), you are also ready to charge when on shore power (or hooked to the TV with the refrig not running on 12V).

The breakaway switch is meant to apply your trailer brakes should the trailer become unhooked from the tow vehicle on the road. It uses power from the trailer battery to do that. So you can think of it this way, if the tow vehicle pulls away from the trailer, it pulls out the plastic plug from the breakaway connector and that runs current into the brakes (discharging the battery). Put the plastic plug in and no current flows (can't drain the battery). So the plug should be installed at all times except possibly a short time to connect the breakaway cable to the tow vehicle.

Don't feel bad about not having a "warm fuzzy feeling" about the electrical system. It is wimpy and needs to be nursed along, especially if dry camping to stretch the amount of time it can be used. It is not very close to ideal and I believe it is not likely to get to camp with a full battery. Several owners advocate the use of two batteries. I think a great deal of this reasoning has to do with the refrig draining the battery while on the road and the very long time needed to recharge it. I am planning to install an IntelliPower converter from Progressive Dynamics or possibly another at some point. This will replace the converter now in the TM. A lot of talk has focused on replacing the 6300 series with the 7500 series converter. I don't think that is sufficiently better (only supplies a little more current). The IntelliPower will quick-charge the battery and avoid overcharging the battery as well.

Hope this helped.

Bob

Big Bend is great and this time of year the snowbirds are heading north so getting a full hookup campsite should not be out of the question. The only thing you do have to worry about are the flash floods, as in all hilly arid regions.

While you are in the BB area make sure you spend a little time on the river road west of the park. And stop by Ft. Davis north of Alpine. In fact if BB is full and you really want full hook ups you might try Davis Mts. State park, they have 30+ full hook up sites at around 6000 feet if DH can go that high. Don't forget to check out the art shops in Alpine for a little different slant on art, I think you'll like it. If you are into star gazing you have to go to Ft. Davis, nice tour at just a little over 8000 feet.

The camp grounds in BB are down by the river, the spring rains mostly come from lower clouds so if you get up in the morning and see rain or fog, make a running trip up to the basin turn around and drive down slowly, you'll most often be above the clouds and that sure is cool. Makes for good photos also.

Great !--my fuse is okay and I now understand the relationship of the breakaway switch to the battery and the way the battery indicator lights work.

Some good places to check out when we get to Big Bend, too. Just reminds why I like the board so much!

Thanks a bunch to both of you!

[RockyMtnRay]

Originally Posted by BobRederick

I'll tackle the questions I can answer and leave the others for the pros.

You did pretty well...you're on your way to being one of the "pros"

A few amplifications follow:

The charging system reads C for charging as you suspected. I don't find this device to be described in the owners manual. I get the highest light on (F) when charging. The next light when well charged without 110V hooked up or operating from battery. The two lower lights are for lower states of charge. (I would like to have a voltmeter on this line myself).

A very important factor about these lights is they should be checked only after the battery has had a chance to stabilize without load and without charging (other than the C light). That stabilization needs at least 15 minutes to occur. If battery state is measured under load (e.g. refer on), it's normal to see only the L and F lights...even with a fully charged battery. Similarly, if you check the lights immediately after disconnecting from a recharging source (shore power, Tow vehicle), there will be a misleading "surface charge" that often will cause even the green "G" light to illuminate when in reality the battery's true state of charge is still down in the "Fair" range.

From my comparisons of the lights versus voltmeter readings with the battery voltage stabilized...
"C" does indeed mean Charging...comes on when voltage gets over about 12.9
"G" means Good. Basically the battery is above about a 35% state of charge.
"F" means Fair. Battery between 15% and 35% of charge.
"L" does indeed mean Low (under about 15% of charge). If you are down to the L level, the battery should be considered depleted...further usage will harm the battery and cause a significant reduction in the battery's amp-hour capacity even when it is recharged. The Grp 27 RV/Marine battery provided by most dealers is not a true deep cycle battery...if you routinely take it below about 30% charge it will have a loss in total capacity.

Frankly, the charging system is pretty wimpy. It can take 40 hours or even more to charge a dead battery to 90%.

True.

Your refrig draws 10 or 12Amps and for half hour that would be 5 or 6 Amp Hours. My battery (factory) is 75 Amp Hour, so a charged battery should run 5 or 6 hours with no other loads.

Most of the Grp 27 batteries are nominally rated at 115 Amp hours...when new and properly charged. However, that's at about a 5 amp rate of drain. At a 12 amp drain rate, they're really about 80 amp hour batteries and you can/should only drain them to 30%....that means about 55 amp hours available or about 5 hours of refrigerator operation.

I suspect your battery didn't get charged fully on the way to the campground. There is so much voltage drop in the TM and TV that the TM battery actually supplies part of the current the refrig draws while on the road.... that means the battery is discharging rather than charging while towing.

Unlike your experience, my conclusion from hundreds of posts here is that most Tow Vehicle/TM combinations do recharge the TM battery while enroute even if the refer is on DC. With both of the TVs I've used (Jeep and Tundra), I've measured a charging current of about 5 to 6 amps into the mostly discharged battery of my TM (which is way in the back of the TM at the end of a very long charge wire)...even when the refer is on DC. There is no reason whatsoever to put up with a situation where the TM battery discharges while enroute when the refer is on DC. Such discharge is not normal and can/should be fixed.

That being said, I'll re-emphasize that the current at the battery is only about 6 amps...and that was with a mostly discharged TM battery. As the TM's battery charge slowly rises from enroute charging, the charging current will slowly drop. There should always be some recharge but it may drop as low as 1 or 2 amps. Hence, a not fully charged battery will recharge some...but not a great amount in a given 4 to 8 hour towing day...and that presumes that there is no period during the day when the charge from the tow vehicle is shut off for more than a few minutes (e.g. an extended stop for lunch). Even a short 15 minute shutoff for refueling will result in about 4 amp hours loss from the TM battery...and it will take nearly an hour of driving to make up for that loss.

Several owners advocate the use of two batteries. I think a great deal of this reasoning has to do with the refrig draining the battery while on the road and the very long time needed to recharge it.

Not really. As one of those with dual T-105 Golf Cart batteries, enroute discharge was not the reason. Rather, most of us do it to be able to have extended (5 to 6 day) boondocking stays without having to worry about battery charge levels. Because the T-105s are true deep-cycle batteries, they can be safely discharged to about 20% of capacity numerous times with no loss of total capacity. Second, the dual batteries provide roughly twice as much rated capacity as the single Grp 27 RV/Marine battery. The combination of twice as much rated capacity and being able to discharge the dual batteries to a lower level of charge means the total amp hours available is roughly tripled over the single battery. That in turn enables a much longer boondocking stay.