Newbie: Dry camping battery issues

[OldRock]

Hi - my first post after buying a new Flagstaff MicroLite 23FB last week. There are some questions at the end but first some background.

We picked up the new TT and took it to the nearest state park, 20 minutes from the dealer, last weekend. The dealer had installed a 100 RC battery and claimed it was fully charged. We were careful about minimal use of lights, pump, etc. - used a Coleman lamp and flashlights. In the middle of the second night the fridge started flashing a check light and activating a solenoid - trying to restart it? I switched it from Auto to Gas and it seemed to run for about 30 seconds, then went into flashing check light again. Turned it off and went back to sleep. Then the CO alarm started an intermittent beep, until it ran out. I then pulled the battery disconnect. With the disconnect pulled the battery level showed 2 lights out of 4. With the disconnect off the whole test panel went dark when I pushed the test button.

Next morning I hooked the cable up to the car and ran the motor for 2 hours. Tried the power tongue jack and it ran for about 3 seconds before dying.

Questions: 1. The dealer says it was all just the result of the battery running flat. Any reason to question that?

2. I just bought a 220 RC group 29M battery to add to the dealer-supplied 100 RC battery. Any issues with connecting two unequal batteries in parallel without an isolator?

Thanks.

PS - I love the trailer. Looking forward to a full hookup on my next trip, but I also plan to do more dry camping from time to time.

[TURBS]

whats the model of battery you have now ?

dont hook two dislike batteries together as they discharge at different rates .

you always want 2 of the same group size.

your co alarm going off was actually its low battery alert .

your fridge would have only been running on gas anyway since no shore power.

but if your fridge has a defrost switch and it was on that will kill a battery fast .






btw welcome to the forum!

[Glenn5995]

Welcome to the forum!

Like f1100turbo said, you will have problems with two mis-matched batteries in parallel. They will try to equalize and the larger capacity battery will not fully charge and it will want to over charge the smaller.

As far as the battery level indicator, the top light with the "C" next to it is to indicate when the battery is being charged. To check the battery condition only three lights are used, the top "F" light indicates the battery is fully charged. The center "G" light indicates the battery is in good condition and the lowest level "E" for empty means you are done.

If you were showing two lights, you should have still been able to power everything. Hooking up to the tow vehicle while it is running will supply some power, but at a trickle rate. It would take days to recharge a battery with the tow vehicle.

You need to have the battery checked. It may show the proper voltage, which is what the indicator checks, but fail under load. Every one of my trailers had to have the original battery replaced shortly after purchase. If they install them in the trailer before purchase, the parasitic power demands will drain them and if they are allowed to go completely dead, in my experience they are on borrowed time.

[TURBS]

to add to glenn's post charge the battery away from the camper with a low amp trickle charger for at least 12 hrs then have it load tested .

[OldRock]

Thanks everyone for the quick response. I don't know the model of the original battery (the trailer is still at the dealer's, 90 minutes away, so I can't check), but it only has a Reserve Capacity rating of 100.

So my choices are to match the original 100 RC battery, or replace it with two that match each other. I'm not sure I want to add the weight of two of the Group 29s so I might downgrade a little to two Group 24s or 27s (still 40% or 80% more capacity each than the original), if I can exchange the one I bought. I'll also see if the dealer will give me a credit to take back the one he supplied.

I'm glad I asked!

[TURBS]

Originally Posted by OldRock

Thanks everyone for the quick response. I don't know the model of the original battery (the trailer is still at the dealer's, 90 minutes away, so I can't check), but it only has a Reserve Capacity rating of 100.

So my choices are to match the original 100 RC battery, or replace it with two that match each other. I'm not sure I want to add the weight of two of the Group 29s so I might downgrade a little to two Group 26s, if I can exchange the one I bought. I'll also see if the dealer will give me a credit to take back the one he supplied.

I'm glad I asked!

Yes 100 rc is not much battery.

[lswartz]

A group 24 12 volt battery lasts 2+ days for me. If you are going to dry camp for longer periods of time, then add the same battery to extend your time. I use two matched group 24 6 volt golf cart batteries in series & they are good for 8+ days.

[TURBS]

Originally Posted by lswartz

A group 24 12 volt battery lasts 2+ days for me. If you are going to dry camp for longer periods of time, then add the same battery to extend your time. I use two matched group 24 6 volt golf cart batteries in series & they are good for 8+ days.

I also use two group 24 batteries.

[Glenn5995]

Correction: The lowest light for the battery level is "L" for low. The "E" is for the holding tanks, but you probably got the idea.

I am using two group 31s in parallel. Trojan SCS225s.

[Herk7769]

To convert RC to AH How can I convert 25 amp Reserve Capacity to Amp Hours at a 25 amp discharge rate? | Discover Energy you multiply the RC by 0.4167.

So, a 100RC battery is a 41.67AH battery.
There are motorcycle batteries with this capacity.

It is, uh, not a great battery. Free is sometimes worth every penny.

The OEM battery I got was 75AH and needs to be replaced with a PAIR of 225AH batteries (total capacity 450AH) for serious boondocking.

FYI

[OldRock]

Thanks again for all the comments. It sounds like two group 24s should be adequate. Two group 29s would weigh 123 lb, versus around 90 lb for the 24s. The trailer is already pretty tongue-heavy, right at 15% of dry weight according to mfr specs. Not to mention the fact that I can barely carry the 29 and I'll take it out for charging between trips (the trailer is going to a storage facility).

[Rod Johnson]

I couldn't make it through a whole night with my single 12V battery either, you'll be much happier with a pair of good batteries. I think I ended up with 2 Group 27s.

Your fridge should have been running on propane the whole time, but there is that safety shutoff valve in the regulator. Mine always kicks off when two things try to run at the same time, like the fridge and heater, or fridge and water heater. Could also be if the trailer hasn't been used for a while, there was a big air bubble in the propane line.

[Glenn5995]

Originally Posted by herk7769

...to be replaced with a PAIR of 225AH batteries (total capacity 450AH) for serious boondocking. FYI

Noooow....that's what I'm talkin' 'bout!

[OldRock]

Originally Posted by lswartz

A group 24 12 volt battery lasts 2+ days for me. If you are going to dry camp for longer periods of time, then add the same battery to extend your time. I use two matched group 24 6 volt golf cart batteries in series & they are good for 8+ days.

Can you tell me a little more about the golf-cart batteries? 8+ days sounds attractive! What brand, size, and where to buy? How does the weight compare to a couple of marine batteries? Thanks.

[Triguy]

OldRock, because of differences with trailers and your needs, you are best to do an energy audit of your actual usage; not someone else's. That inventory is critical because it will be personalized to you. The goal is to understand how much electrical energy you'll need for your situation

Make a list of your 12-volt items and their listed needs in amps or watts. You can actually measure the current draw, or you can use the rated current on the appliance label. Convert watts to amps with this formula: amps = watts/volts. So, if you know the watts divide by 12 and you've got amps.

Estimate how much time you’ll use each device in 24 hours. Obviously most items don't run continuously, but some do. Do your best to be accurate with your usage.

Multiply each item's DC amps by its hours of use for the day and you'll get the amp hours (Ah). Total the list.

Remember that batteries should never be drained lower than 50% of full charge because that greatly shortens their life. So, if your total is 50Ah per day, for example, you'll need a minimum of a 100Ah battery bank to last one day. 200Ah for two days. 400Ah for four days. You get the picture.

Personally, my two Trojan 6-volt batteries (T-145s) wired in series provide 260Ah (20-hour rate). This lasts us about 4-5 days when we are judicious in our power consumption, which doesn't always happen with our three kids. 3-4 days is more like it. But, again, that's us.

YMMV.

[Herk7769]

Once again Triguy has the best answer.

[lswartz]

Originally Posted by OldRock

Can you tell me a little more about the golf-cart batteries? 8+ days sounds attractive! What brand, size, and where to buy? How does the weight compare to a couple of marine batteries? Thanks.

I must differ to Triguy & Herk, they both know more about this than I do. I bought 2 6 volt golf cart batteries from Sam's Club in 2001. I was able to get 8+ days with them. One started to fail this Spring so I replaced it with one from Advanced Auto (I was leaving the next day & they had one in stock). Since then, Herk was nice enough to explain that they needed to be replaced in pairs so now I have two from Advanced Auto parts, 216 AH. They are not nearly as good as Triguy's Trogan T-145's but they were only $85 (use the $35 online coupon). I am hoping that I can get 10+ years out of these batteries too.

I forgot, they are 64 lbs. each.

[crasher]

Originally Posted by Glenn5995

Correction: The lowest light for the battery level is "L" for low. The "E" is for the holding tanks, but you probably got the idea.

I am using two group 31s in parallel. Trojan SCS225s.

These batteries are awesome. BTW, they fit in a Group 27 box. Love mine.

[Herk7769]

On the subject of the battery "idiot" lights.

The "LOW" (bottom) light will stay on until the battery hits 6 volts. A this point your battery is pretty much shot and will most likely not ever again accept a full charge.

When the "FAIR" light goes out, the battery volatge just dropped below 11.60 - 11.65 volts. This is an almost totally dead battery with less than 20% capacity remaining. Permanent reduction of total capacity has occurred.

When the "GOOD" light JUST goes out, the battery voltage just dropped below 12.10 - 12.15 volts. This means you are at the 50% depleted state where every source that deals with deep cycle batteries say you should recharge in order to avoid PERMANENT battery capacity reduction.

The top light is "CHARGING" it is on REGARDLESS of battery charge condition as long as there is charging voltage (above 12.70 VOLTS) on the buss. Your battery can be disconnected and as long as your converter is working all 4 lights will be on.

Once you go OFF shore power, the battery voltage will drop even with minimal use to the "GOOD" state. When the GOOD light goes out, you must recharge to prevent permanent battery impairment.

Discharging below "GOOD" will result in early battery replacement.

[OldRock]

Once again, thanks to all for the very helpful information. A lot to think about and some homework to do. Much appreciated!