Battery suggestions

[Roger2347]

Good afternoon,
I just purchased a 1991 excella 34’ with duel batteries. The trailer was missing the batteries and I need to buy new. Thanks!

[DKB_SATX]

If you're a Costco or Sam's member that's a good option for batteries.

I'm not 100% sure but I think group27s will just barely fit in your battery boxes, group 24s will be an easy fit. If the Group27s fit, you get a bit more amp-hour capacity from those.

Flooded lead-acid batteries are the cheap choice. Look for actual deep-cycle RV batteries, not the hybrid start-plus-deep cycles if you can. AGM batteries are a bit more tolerant of abuse, but many think they're not worth the price premium.

If the Excella has its original converter-charger, modernizing that might be worth it. I had good luck with a Powermax Boondocker converter-charger from BestConverters. No one ever complains about Progressive Dynamics "Intelli-power" converter-chargers (don't cheap out, get one with the ChargeWizard.)

[batman]

So many threads out there already. check here, http://www.airforums.com/forums/f449/ .

6v or 12v,
Lead Acid,
AGM-Absorbent Glass Mat,
Lithium,

How often will you be using them?
How much do you want to spend?

-Dennis

[Bill M.]

Pair of group 27 deep cycle batteries. Flooded cell if you have the original converter. Walmart or other outlet. Group 27 fits tight but fits. Group 24 is lighter and smaller. As mentioned, an upgraded converter would be a good thing.

[uncle_bob]

Hi

Don't bother with the original converter. Pull it out and replace it. It's well past it's use by date and technology has advanced a lot since then. Avoid the "cheapest thing on Amazon" converters. You want at least one or two steps up from that.

Battery wise - what do you intend to do with the trailer? If you pretty much never run off grid, go for the cheapest deep cycle batteries Costco will sell you in group 24 case size. If and when they die, replace with the same thing. If you are planning to add solar and try to run off grid for weeks, figure that out first. You likely will put in more batteries than originally came stock.

Bob

[Roger2347]

Hey bob I got a converter. It’s a 3000w AIMS POWER
GLOBAL LF Series. You think that will work?

[DKB_SATX]

Originally Posted by Roger2347

Hey bob I got a converter. It’s a 3000w AIMS POWER
GLOBAL LF Series. You think that will work?

Looks like the "Global LF Series" is an inverter-charger handy dandy combo thing. It'll probably do a great job of charging batteries as long as you set it to the correct battery type to match what you buy.

[Roger2347]

Thanks everyone! This is going to be a new learning experience and will be asking a lot more questions lol.

Thanks again for all the help!

[uncle_bob]

Originally Posted by Roger2347

Hey bob I got a converter. It’s a 3000w AIMS POWER
GLOBAL LF Series. You think that will work?

Hi

There's a lot of setup on that unit. Plan on spending a while working out all the various issues with setting this or that. You do *not* want to get it set up to put 15V on your batteries on a regular basis ( ok, it's 14.8, but same thing ....).

Like all inverters, it pulls a lot of power. They go on and on about how low power it is. Eventually they toss out a "0.8 to 1.8% of full power" number.(page 11 in the manual).

Assuming that 3,000W is full power, that's going to be 24 to 54 watts. Put another way, its parasitic drain will be in the 2 to 4A range. Hopefully that drops a lot if you turn off the inverter section ( = make sure you can turn off the inverter section when you install it ....).

At least as far as I got in the manual, they don't mention the parasitic drain with the inverter off. Most of these units do have a drain even with the inverter off. That just comes with the way they build these beasts. The magic "brain" needs power to keep doing its thing.

Bob

[waninae39]

go Lion battery

we have Battle Born Lion, they work very well

longer life than lead acid
can go down to 10% of capacity vs 50% ( with reduce life)
are much lighter
same form factory

we moved our inside the AS and that reduce tongue weight

get a suitable controller
we are happy with the victron Muliplus inverter/converter

[Roger2347]

So now it looks like I need a converter. I had the trailer plugged in shore power. The lights kept getting dimmer and dimmer.. until the batteries died. Any suggestions?? Thanks again!

[uncle_bob]

Originally Posted by Roger2347

So now it looks like I need a converter. I had the trailer plugged in shore power. The lights kept getting dimmer and dimmer.. until the batteries died. Any suggestions?? Thanks again!

Hi

Does your planned use for the trailer include an inverter? If so combined charger / inverters are an option. The Victron Multi-2000 and Multi-3000 are options I would consider:

https://shop.pkys.com/Victron-MultiP...00_p_2554.html

https://shop.pkys.com/Victron-Energy...02_p_2431.html

Unless you just *have* to cram in in someplace (as I did) the 3000 is the obvious bang for the buck winner there.

Size of inverter or size of converter gets you into the size and number of batteries you plan to run. Are you going with "lowest cost from Costco" (which is fine) or a bank of six Battle Born lithium's (which is also fine, and a *lot* more money). A 3,000 W inverter or 100A charger is not what you want for the two group 24's from Costco, but fine with the lithium's.

There are a lot of basic converters out there for a simple setup. Expect to pay about $200 or so for a reasonable one. Even with a "better" one, there's no guarantee it will be 100% perfect. Best Converters has a lot of happy customers on the forum.

Bob

[batman]

Originally Posted by Roger2347

So now it looks like I need a converter. I had the trailer plugged in shore power. The lights kept getting dimmer and dimmer.. until the batteries died. Any suggestions?? Thanks again!

Batteries, and controller, good. Ok Here is a place to start. http://www.airforums.com/forums/f449/

Progressive Dynamics make a very good quality units.
https://www.amazon.com/dp/B0039T059U..._t2_B000GASX9O

I have a Blue Sky 3024i with pro remote that works flawlessly.
https://www.amazon.com/dp/B0039T059U..._t2_B000GASX9O

What about solar as well? You might want to plan for that at this time even though you may not POP for it now. Figure out a design, plan for wiring and components. Sorry getting ahead of you hear.

-Dennis

[DKB_SATX]

Originally Posted by Roger2347

So now it looks like I need a converter. I had the trailer plugged in shore power. The lights kept getting dimmer and dimmer.. until the batteries died. Any suggestions?? Thanks again!

I thought you had a huge (3kw) inverter-charger? AIMS Power Global LF?

If you have that and it's wired in properly it should charge your batteries when you're on shore power.

[Roger2347]

Maybe I’m confused then. I do have a 3000w inverter that I have not hooked up yet. But I thought the converter in the trailer would convert the 120v ac to 12v dc? So I could run the lights indefinitely as long as I was plugged into shore power. Is that not the case? Or is it just charge the batteries? If that’s the case I may have to look into a bigger battery bank. Thanks again!

[DKB_SATX]

Originally Posted by Roger2347

Maybe I’m confused then. I do have a 3000w inverter that I have not hooked up yet. But I thought the converter in the trailer would convert the 120v ac to 12v dc? So I could run the lights indefinitely as long as I was plugged into shore power. Is that not the case? Or is it just charge the batteries? If that’s the case I may have to look into a bigger battery bank. Thanks again!

The AIMS Global LF series are inverter-chargers combinations. A single unit that does both. I don't know how efficient it is for standby, but you can probably turn the inverter section off when you don't need 120v power off the batteries and just use the charger section.

If the converter in your trailer was properly hooked up and working, it would provide 12v power for house systems in addition to charging the batteries, yes. Just like the AIMS will do, but the AIMS will go it one better with its inverter abilities.

[uncle_bob]

Hi

The other advantage of an inverter / charger is that you only run one set of cables. With a converter / charger plus an inverter in another box, you run cables to each of them. With a 3KW inverter, those cables are going to be pretty massive, what used to run to your charger is not going to be anywhere near big enough.

Next layer is how much battery you have. A pair of typical group 27's (you may have smaller group 24's) get rated at about 180 amp hours or so. Normal charge rate is capacity / 5. That would be about 35A in this case. Anything over capacity /2 is not a real good idea at all. A charger in the 30 to 70A range is what you normally would use.

The same thing applies to discharge. 3KW at 80% efficiency and 12V comes out to about 312A. Lead acid batteries don't like discharge at 2X their capacity rating. The normal batteries would likely hold out for no more than 10 minutes.

Normally this size inverter / charger gets put on something like 300AH of lithium's or 600AH of lead acid's. (both have the same usable capacity).

Indeed you can run the device at lower power levels. The gotcha there is that it's designed to run best at higher loads. Running it at very low power is going to waste a lot of energy. You also have the "risk" of somebody turning on a hair dryer .... A 1KW inverter is a better match for the stock batteries.

You can put in more batteries. Lithium's are the "cool new" approach. They are (to say the least) a bit expensive. The more conservative (and cheaper) alternative is to stack up Trojan T-105's. A set of six of them would be a good match for the inverter / charger mentioned earlier.

Bob

[pteck]

Roger, I would recommend you spend money where it matters and makes the most difference.

1) Get 2x group 27s normal flooded lead acids and toss them in the box.
2) Keep your converter if it's still working. It does all it really needs to do. There's no point in having a fancy converter when you invest in #3
3) Spend your money on solar. It's commodity priced today and likely cheaper than batteries. Batteries don't make power. Solar actually produces it and can keep your battery stores going indefinitely. The solar charge controller becomes the defacto charger and maintainer in this situation, relieving any needed smarts from the charge converter. I recommend 400W for all you will likely use.
4) If you need an inverter and 120V power on tap throughout your trailer, do this.

You'll have an easy to install and easy to maintain system, more flexibility, more tolerance to extreme weather, invested way less, and have a high performance with deep reserves. Which is what matters in the end.

[uncle_bob]

Hi

In the land of perpetual sun, pure solar may be fine

Up here around the Great Lakes, you need battery backup. There most certainly will be days (.... weeks ....) where the combination of weather and available sites does not allow much solar production.

First work out what you will be doing. Will you ever operate off grid? If so, will you do it for days at a time or weeks at a time?

Next up, add up what you will be using for power. The fridge at (likely) 24AH a day is on the list for just about everybody. It's a good bet that some days the fan(s) or the furnace (depending on season) will chew thru another 25 to 40 AH. Past that there are a lot of things that might be on the list.

If your "budget" is 70 AH a day (maybe it is ... maybe it isn't), then you need 140 AH of lead acid to get through that day. Two days would be 280 AH. With lithium two days would be 150 AH. For me, 3 to 4 days worth of "backup" is about right.

If indeed the *furnace* is the main power hog, you may well need almost all of your power budget from the end of the solar day to the start of the next one. There are a lot of posts about that each fall ....

Bob

[DKB_SATX]

@pteck Roger already owns a high-end inverter-charger, so that's sunk cost. Solar costs less than it used to, but it's not free... and sunk cost is essentially free.