Chargers, converters, etc.

[tsilb]

I'm planning to have solar, but as a backup, I want to be able to charge the house batteries off a generator or shore power. I'm sure that plugging them directly into the batteries would be dangerous, so something needs to go in between to make sure the batteries are being charged at a safe amperage.

I know there is a device called a Charger, which plugs into a 110/120V outlet (wall, generator, shore power, etc) and I'm pretty sure it does this...
I know there is a device called a Converter, which is what RVs have to take shore power, which usually take 110/120V/30A or 220/240V/50A power.
I may or may not get a continuous-use solenoid / battery isolator. Haven't decided yet. I plan to camp about a week at a time and probably only drive 50-100 miles between campsites most of the time. Longer travels should be pretty rare once I settle down.
I'll need a wifi or cell signal for work, so I may end up in or near campgrounds most of the time. At least at first. So hookups are a very real possibility, at least some of the time.

So my questions:

1. Why are these two different things? 
2. Do they know they need to limit the power being passed through when the solar controller is also charging the batteries? How can I verify this is being done correctly? Do they talk to each other? Do they interfere with each other? Do I need to switch the solar disconnect off when hooking up?
3. Is there an advantage to a converter/inverter or is it better to leave them separate? I assume it wouldn't work off the solar.
4. Is there any danger inherent to "speed" chargers?
5. How can I choose the best charger for me? I don't know anything about brands, types, etc.
6. What else do I need to know about charging from multiple sources?

I plan to have 500W 12V solar, MPPT controller, and probably 400-600Ah or so of sealed AGMs. I want to be able to last through a few days of bad weather.

 

[highdesertranger]

yes there is a difference between a charger and a converter.

a charger is just that, a charger. most chargers are dumb, meaning they need to be babysat. you must constantly watch them so you don't over/under charge your batteries. there are smart chargers but they cost considerably more.

the RV converter is a charger and a power supply, meaning it can power your devices at the same time it charges your batteries. most of the newer converters are smart chargers. stay away form the converters that are dumb.

highdesertranger

 

[John61CT]

AFAIC converter is just a US RV industry term for the more generally used charger.

Within both you get dumb and smart.

The two charger lines I recommend, Sterling ProCharge Ultra and ProMariner Pronautic P, are as smart as can be, very adjustable and robust.

I don't know of advantages any converter may have over these.

> I'm sure that plugging them directly into the batteries would be dangerous, so something needs to go in between to make sure the batteries are being charged at a safe amperage.

What is "them" referring to above?

No problems IRL with multiple charge sources working in parallel.

Ideally they have similar setpoints, but NP in any case

The Combi units require a greater investment, eggs in one basket, if you outgrow one or the other, bigger cost to upgrade both.

 

[tsilb]

What is "them" referring to above?

Between the battery bank and the charger/converter.

 

[John61CT]

"Fast" chargers usually flags cheap garage style designed for automotive starter batts, not deep cycling.

But No, lead chemistry banks are not harmed by too high amperage available, it is battery resistance that controls the acceptance rate.

But big amps requires more robust wiring, connections etc for safety.

FLA bank I recommend minimum .15C, up to .3C for expansion, so 15-30A per 100AH.

AGM .3C is l minimum, really up to
5-.6C is better, so 30A to 60A per 100AH.

Good quality chargers can cost as much as the bank or more, but batteries are a consumable, the adjustable chargers are more future proof for different chemistries, should last longer than your vehicles.

 

[John61CT]

I would advice a higher panel:bank ratio, unless your locations are always sunny.

And why AGM? More expensive, less robust, can't get SoC data with a cheap hydrometer. . .

 

[highdesertranger]

yes, there is a difference between a converter and a charger.

a converter is also a regulated power supply. it will deliver a steady 13.8 volts to your accessories no matter the battery or charger voltage is.

highdesertranger

 

[tsilb]

I would advice a higher panel:bank ratio, unless your locations are always sunny.

And why AGM? More expensive, less robust, can't get SoC data with a cheap hydrometer. . .

I don't want to have to worry about acid gas venting into the living area. Don't they also hold up to deeper cycles (50%)?

 

[tsilb]

Between the battery bank and the charger/converter.

I totally said this wrong. I meant the charger/converter goes between the battery bank and the power source. I've read that some people have run power directly to their batteries from the power source, and that seemed dangerous. No regulation etc.

 

[John61CT]

> it will deliver a steady 13.8 volts to your accessories no matter the battery or charger voltage is.

That happens to be my main charging rate, for LFP.

But if that were set higher for lead, does it have a completely separate output for the load circuit?

If so, is the reason for that approach to protect sensitive load devices when manually equalizing, say at over 15V?

Do converters often have that capability?

 

[John61CT]

> acid gas venting into the living area
AGM offgas too, just less, should still be boxed and vented IMO

> Don't they also hold up to deeper cycles (50%)?
Better phrased "have a longer lifespan, # of cycles, when used for deep cycling". All batteries last relatively longer with more shallow draw-down

That is the case for all true deep cycling batteries, which are available in FLA, AGM, and GEL.

The best value is Duracell GC 6Vx2 from Batteries+ or Sam's Club, $180 per pair for 200+AH.

The main three good AGM mfg in the US are Odyssey, Lifeline and Northstar. They are relatively expensive, but 99% of the rest are not proper deep cycle.

 

[Weight]

There must be a fuse between the charging source and the battery bank. Very close to the battery positive terminal.

 

[heron]

The best value is Duracell GC 6Vx2 from Batteries+ or Sam's Club, $180 per pair for 200+AH.

Just looked online at batteries+, and the least expensive is 149.99/ea. Is $180/2 sale price, perchance? In the event that the $149 figure is what there is, these days, is the Trojan T-105, at 10 bucks more, a better deal? I have been reading and reading about batteries (in which I have previously had no interest whatsoever) until my eyes bleed, and feel as though I don't know much more than I did when I started. Also, do I understand correctly that a smart converter/charger isn't the best idea? Our recently acquired 1988 Dodge Roadtrek has all original equipment (including the deadest battery ever), and from what I gather, the converter thingy isn't too bright. I'm about to hit the road with my very frail husband (Parkinson's+), and would like to think that this is all going to work out, and we'll be able to stay on the road for a good long while, so am thinking of solar, at some point, assuming it'll fit properly on our roof, so would like to gear up with that in mind. We want to hit the road, asap, so will be planning on using the batteries , and we have a little 300W Honda generator that's older than the RV, to charge things up, if that's possible. Honestly, I haven't even tried to figure that out, yet. I surely would appreciate your thoughts on this, and apologize if I'm asking the most ignorant questions, ever. I can weld, and I can build things, and I've done a fair amount of wiring in the house(with advice from my electrician son-in-law), but electricity generally baffles the hell out of me.

 

[John61CT]

That sounds wrong, are you sure? Link?

No Sam's nearby?

Cosco? Not as good but cheaper.

But the Trojans are great.

A converter is basically a powerful charger, Progressive Dynamics are good.

Look for 30-80A if you can afford it.

Promariner pronautic chargers are my top choice, very adjustable.

300w gennie? Is very small, make sure the charger can derate, not overload the gennie.

 

[heron]

That sounds wrong, are you sure? Link?

No Sam's nearby?

Cosco? Not as good but cheaper.

But the Trojans are great.

A converter is basically a powerful charger, Progressive Dynamics are good.

Look for 30-80A if you can afford it.

Promariner pronautic chargers are my top choice, very adjustable.

300w gennie? Is very small, make sure the charger can derate, not overload the gennie.

Was looking online at the Batteries+site. Could have missed it. Maybe the search page took me to retail prices, though that would be odd. Also, I had been reading what, to me, is a foreign language, for a few hours before I read your post, so I swear to nothing. Just noticed that tab was still up: https://www.batteriesplus.com/search?q=duracell+gc+6v Aaaand just went to the Sam's Club site, where they have them for 84.52/ea. So have to join there, and it's closer. Heading off shortly.
Progressive Dynamics (30A) is what I have, but it's 30 years old, so I figured what I'd read about older ones not being smart enough, probably applied. It's a 720(1,2,or 3)Q. Doesn't say on it, and I've rarely seen less forthcoming documentation than is on on this entire vehicle. Maybe when it was new, it cost enough that only those who could afford to take it to be fixed, bought it, but that was then, and this is now. I'm still not sure if you're saying two separate things, one to charge the batteries, and one to convert from AC to DC?
From what I read after I posted my questions, the 300W probably will not do the trick. I think. Think there's a 1000W Honda I can get my hands on for a reasonable price. Might that do it?
Thanks so much for your help. Never been on a forum before, so if I'm hijacking someone's thread, I apologize, and can move it to its own.

 

[Jmel]

I like the idea of the 2x 6v batteries for 180, great price. Problem is that a vented box has to be built and all this other stuff comes with having a flooded battery inside the vehicle.

I went with AGM SLA because it seemed safer. I only have 2x 35ah batteries now, but was looking at a 12v 200ah battery to replace them.

The cost is pretty much double that of the 6v flooded batteries, but you don't have the risk of gassing the interior either.

 

[Jmel]

> acid gas venting into the living area
AGM offgas too, just less, should still be boxed and vented IMO

> Don't they also hold up to deeper cycles (50%)?
Better phrased "have a longer lifespan, # of cycles, when used for deep cycling". All batteries last relatively longer with more shallow draw-down

That is the case for all true deep cycling batteries, which are available in FLA, AGM, and GEL.

The best value is Duracell GC 6Vx2 from Batteries+ or Sam's Club, $180 per pair for 200+AH.

The main three good AGM mfg in the US are Odyssey, Lifeline and Northstar. They are relatively expensive, but 99% of the rest are not proper deep cycle.

I wasn't thinking AGM had to be boxed and vented - they are used in tiny enclosed spaces all the time.

 

[John61CT]

No battery "has to" be.

If you aren't sensitive to the smell and aren't willing to ventilate the living space once in a while, then do it.

Can start out without, do it later.

Yes AGM gasses much less.

Only safety issue afaic is never enclose in a sealed box without venting, boom bad!

 

[Jmel]

No battery "has to" be.

If you aren't sensitive to the smell and aren't willing to ventilate the living space once in a while, then do it.

Can start out without, do it later.

Yes AGM gasses much less.

Only safety issue afaic is never enclose in a sealed box without venting, boom bad!

Understood... I took SLA to mean "sealed" as in... nothing gets out. My 1990 G20 conversion van is not a sealed box by any means, so it would certainly get some ventilation even when the van is just parked with no windows or doors open.

I just do not want to have a dangerous situation because I go with a flooded battery instead of the SLA.

 

[John61CT]

Common misconception, false advertising.

No, no danger of explosion if FLA left open, and IMO wrt health, the smell will bother you long before any real issues, just increase ventilation while they're bubbling.

But to me a vented box is hardly any trouble compared to the rest of the build, so that's what I usually recommend for any lead bank.