Chinook RV

So, after one more trip in a couple of weeks, I'll likely be parking my camper for most of the summer. Which fills me with dread on account of spending a pile on new batteries during my trip last fall, and having a trip out to Big Bend planned for next fall, which requires batteries in good condition. So far, they seem to still be doing great, but the weather is heating up, which has, historically, meant doom for my house batteries.

I'm not ready to replace the charger yet, but the driving battery has done very well since I put a battery tender on it a couple of years ago. I have an extra lead for that tender, so I'm thinking about disconnecting the house batteries from their circuit and hooking them up to the tender.

(Here's what I'm using on the car battery: https://www.amazon.com/gp/product/B000NCOKV0/)

Are there any reasons you know of that I shouldn't do this? Is it usually a problem to put a tender like this on batteries wired together? (Maybe I'd be better off getting a second battery tender and handling each battery separately...)

If I do this, what happens if I leave the coach plugged in to keep lights and water pump available while I'm working in there?

When you said you have not replace the charger, you meant the parallax charger inside the brown box? It has no effect on your battery unless you are plug in. It will be counter productive to disconnect your batteries run your generator, and use the battery tender to charge your batteries.

you can use the battery tender use one lead for the coach battery under the hood and use the spare one for the dual coach battery. The only caveat is that the two parallel coach battery need to be matched, meaning that they were not different brand, made by different factory, or you use one for a while, and left the other one in storage, etc. If they are matched, the tender will see it as a large battery. You can also have the tender attached to the batteries while you turn on the pump or light.

Now, here is my question. The tender is a good tool to use when you have your rig (i.e., batteries) in storage long term. When you are out camping, how are you going to keep your batteries charged? Typically, you can charge your batteries when you drive around (alternator), under the sun (solar panel), run your gen set (parallax charger) or plug in on camp site (shore power with parallax charger). Depends on your usage scenario, having the tender or no may not make a difference since it is only 1.25 amp and only good for keeping your batteries topping off.

Thanks for the reply. I see that more clarity is needed. I don't know why people can't read my mind yet...

I have covered parking with a couple of 20A outlets available to me. Up to this point, when I park the rig in storage, I just plug it in like I would at a campground, and add a tender to the car battery to keep it happy.

My new, vague, hand-wavy plan is that when I'm camping, I'll hook the batteries up normally - stock configuration - using the vintage charger in the brown box.

Then when I put the camper in storage for weeks or months, disconnect the batteries from the coach circuit and put them on the tender.

Not sure how to make that a fast and easy process, but if I can save my batteries instead of killing them in a season, totally worth the effort.

I'm fuzzy on what to do for indoor power while it's in storage. I believe the tender can keep up with the small parasitic loads and occasional use of lights and water pump, but have doubts that it would be up to the job if I, say, left the fridge plugged in. And I'd want to plug in on occasion so that I can use fans and power tools for my continuing interior deconstruction.

Your setup is fine. Just make sure that nothing is pulling more than 1.25 A for a prolonged amount of time. For fans and power tools, if you are plug-in to shore power, just use the 110V AC receptacles. The fridge is pretty demanding on DC, but if you have it plug in to shore power, you can also switch it to AC, and it should be fine. However, I won't leave anything in the fridge for more than a few days... unless it is just beer and soda, etc. that is not prone to spoilage.

Not sure if I'm reading you correctly, but if I am, you are going to store the Chinook for the summer, have power available, and are hoping your batteries stay healthy until you go out again in the fall.

Well, you are right to be thinking about it, because batteries HATE heat. I think the best thing, if you could, would be to remove them and put them in a climate-controlled space. I had to leave my Chinook once for three months in indoor-but-roasting storage, and that's what I did. They sent me a thank-you card

If you can't do that, then yes, try to keep them charged up but no need to kill them with it either. Batteries want to be charged with less voltage when it is hot (and more when it is cold) so a dumb charger that just blasts on as if it were always room temperature isn't really what you want (better chargers are temperature compensated for that "just right" voltage in all temps).

You can turn off the "charger" breaker on the AC panel and then the charger won't charge the batteries. Unfortunately, I think that means you can't use any of your AC loads either, because the brown box encourages coach builders to use one wire for both (hence goofball "store" buzzer). But then are you really going to be hanging out in your Chinook in storage in the heat? (If so there may be alternatives, but are you?).

If your combiner is working properly, I would think that if you put the maintainer on one bank, the relay should open and charge the other bank too. If the 1315 it will go either way; if the 1314 it will go Ford to Chinook but not the other way.

You can test this if you have a simple voltmeter ($10).

1) Put the meter on DC voltage setting. If you have a choice of scale, 20 volts is fine.

2) Before you put any charging on (and with solar not going), put the red probe on the positive post of the Ford battery and the black on the negative. You should see something like 12.5 volts (best if you have not driven in a few hours to let surface charge bleed off from the alternator).

3) Do the same for the house batts (one batt is fine).

4) Now put your tender on the Ford battery and activate it.

5) Now read the Ford battery voltage again. You'd expect something around 13.2 volts or more. (if you reverse the positive and negative probes nothing bad will happen; you'll just see a negative voltage instead, like -13.2 volts).

6) Now read the house batteries. Are they also showing the charging voltage? If so then your separator is letting the charge through.

7) If you want to for fun you could try it the other way.

I think this would work because the separator (at least the ones I know) are just relays. In other words, it is just a troll at a bridge (If this is too basic, just skip). The troll normally keeps the bridge closed. If the troll senses charging on one of the batteries, it opens the bridge so the two battery banks can share (nice troll!). If the charging voltage stops, then the troll closes the bridge again so that the two kingdoms are separate. They only share when times are good

The troll is doing what a charging relay does.

If there is something wrong with my idea, I bet someone like chin_k will see it. He's crafty that way

Or if I misunderstood your intention, let me know.

I forget that there is a solenoid that connect the coach battery with the chassis.

It is fine for the most case, but if you are picky about getting the most out of the batteries, trickle charge the other bank thru the solenoid may not be the best. This is because when the solenoid open the gate, if the voltage is different from each other, there will be voltage frustration that mess up the charging curve for the charger.

For Kirah's case, if all the batteries are at top off voltage, it may not be that important at that point whether the solenoid connect or not. It is just simpler with solenoid compare to a separate, temperature compensated, multi-parameter charger for each battery. Since Kirah battery tender has two taps, it is better to use the separate taps for the coach and chassis instead of relies on the solenoid. By the way, if you keep the batteries topping off, the solenoid will be active all the time, and you can feel the warmth of the solenoid. Mine is not in the recall list, but I got it removed to stop it from clicking as the voltage goes up and down due to the solar panel charging the battery.

Awesome. We're all on the same page, and it sounds like this should at least be a step up from what I've been doing. And I shouldn't explode anything by plugging it in without batteries in the circuit, so I can use 120v when needed.

I really don't want to move the batteries because A) they're heavy as &!@^@#$& and B) I don't have a lot of climate controlled space (house is small and full of projects already) and C) then I'd have to remember to haul them back over whenever I want to take a last-minute trip. The storage area is about half an hour from my house, so forgetting that detail would put me substantially behind schedule.

I do want to go over there and work when it's hot, because I'm too busy camping and gardening when it's not hot. How much progress did I make on my remodel this winter??? Very little. I took out the dinette and cut through some bolts. Too busy doing other stuff. And hot is, like, 8 months out of the year. I wish the A/C pulled less power so I could use it while the rig is in storage.

Remember that I forget about the solenoid in the previous post? Well, I forget about it again. What you need to consider is that the battery tinder, although has two separate taps, it may not be happy if the solenoid connect. This is beyond what I can figure out from the arm chair, and you may want to call the manufacturer to find out if you need to disconnect the solenoid.

As for the AC, I think you should look into getting a 30 Amp outlet in the storage so that you can plug in your rig. The important thing is that when you remove the heat from inside the rig, the heat need to go somewhere, so it will only work if you have good ventilation outside the rig. It is going to be bad for the rooftop AC if you put it inside a small storage that is totally enclosed, and keep it on for hours.

I hope no one turn on the propane heater to keep warm in the winter in a enclosed space either.

chin_k wrote: March 11th, 2019, 2:02 pmAs for the AC, I think you should look into getting a 30 Amp outlet in the storage so that you can plug in your rig.

That's exactly what I had done in my pole building. Basically "shore power" for the rig when in home storage. Good investment and peace of mind, for sure.

It's a rented space in a storage lot, so 30A power is not likely to happen. I'll ask, though - it's relatively new, so maybe they over-engineered the electrical enough to accommodate it. Not enclosed, though - just a big open-sided structure with a high metal roof.