Boondocker converter

[wg4t50]

Jeremy,
Correct on lead acid flooded batteries, but bot on Gel Cell batts.
When you raise the voltage on a 12 volt battery to about 16+ volts, it is referred to "Equalizing", on sone batteries we equilize them about every 6 months for about halh hour on a 8D size that is used on sone standby generators.
FWIW
Dave M

[Iceni John]

Wow: Thanks everyone, it has become apparent to me by all your replies that I know nothing about converters!  What I thought was a simple question now has me scratching my head LOL.

I know what desulfation is but the technical how it works stuff, no.
I have  no idea what this is.

Equalization is one of a charger's four modes.   Good chargers (good being the operative word here) should first Bulk charge batteries at between 5 and 13% of their 20-hour Ah rating, at least for flooded lead-acid such as T-105 golfcart batteries, then they should switch to Absorb mode when the batteries accept a reducing amount of current, then finally to Float when they get a trickle-charge essentially for maintenance.   In order to prevent stratification of the electrolyte, when the acid is stronger at the bottom and the top is weak, an occasional over-voltage charge called Equalization will bubble the electrolyte and mix it all equally, giving longer plate life to the batteries.

I will be buying two Morningstar TS-MPPT-60 charge controllers for my solar panels  -  here is their explanation of this:  http://lib.store.yahoo.net/lib/wind-sun/TSMPPT-manual.pdf   See page 19.

Desulfation is, as others have aluded, an iffy process at best.   Until I see incontrovertible scientific evidence that it works, I'll equalize my batteries every month or two.   Besides, with a good solar system there shouldn't be any need to desulfate at all, because the batteries are always being fully charged every day.   Sulfation mainly occurs when batteries sit for a while in a discharged state  -  that is when the sulfate crystals that grow on the plates will permanently harden.   If you don't discharge FLA batteries less than 50% SOC and if you recharge them promptly and fully every day, they won't sulfate.   Off-gridders with cheapo golfcart batteries and a good solar system are getting up to eight years or more life from them, which is unheard of if they weren't being charged by PV.

For serious boondocking the only question about having solar is when and how much you will eventually buy.   Using a generator to fully-charge batteries is expensive  -  at least use a gen to Bulk charge them, then finish with solar.   PV panels may still be coming down in price  -  a few years ago they were several dollars a watt, but last year I bought some UL-listed made-in-USA Sharp panels for $0.81 a watt, crazy cheap.   PV now is relatively cheaper than batteries, so PV systems are now having more panels and less batteries than ever before.   The days of having lots of batteries but only a few panels are over  -  now there's no excuse to not fully charge one's batteries all the time!   This means that sulfation should be less of a problem than in the bad old days when people expected a few hundred watts of PV to correctly charge lots of batteries (which they never could do).

I'll be totally dependent on solar for all my electrical needs  -  my generator will be for emergency back-up use only.   With 2,040 watts of panels I'll have no problem getting my eight T-105s to Float each day by noon:  I can be pushing up to 120 amps into them in Bulk mode!   After they're fully charged, all the panels' output can then power opportunity loads such as power tools, air-conditioning, even the electric heating element in my Suburban water heater.   Imagine  -  free silent dependable electricity for many decades!   Yeah!   (OK, I know nothing's actually free, but for me it's better than the alternatives.)

John    

[Jeremy]

Jeremy,
Correct on lead acid flooded batteries, but bot on Gel Cell batts.
When you raise the voltage on a 12 volt battery to about 16+ volts, it is referred to "Equalizing", on sone batteries we equilize them about every 6 months for about halh hour on a 8D size that is used on sone standby generators.
FWIW
Dave M

I don't know much about AGM batteries but I've never understood 'equalisation' to be a desulphation process as such. But - certainly - the boiling etc I was referring to is only applicable to batteries with a liquid electrolyte

Jeremy

Edit - Iceni John makes some very good points there, especially that a properly looked-after battery shouldn't need to be desulphated in the first place. The fact that I've read-up on desulphation a bit in the past is because I have an unfortunate history of abusing my batteries (even today I don't own a battery tender, never mind a decent solar panel set-up)

[wg4t50]

This may or may not answer your questions about equilizing batteries, but you can google lots of info.
Dave M

Equalizing Batteries

[eagle19952]

On the subject of equalization charging....I have been taught that proper battery maintenance is a process that demands frequent equalization, in that the more often that it is done, the less likely the battery will sulphate.
If the frequency is 1 time per month the time period that the batteries need to boil is minimized and thus reduces loss of the water.
The Xantrex Freedom Marine 30 that I have uses a temperature sensor attached to the positive cable ( and it's internal ability to read volts and amps etc.) to assess the state of equalization at plus 14.6v.
incidentally you can not access the eq charge without the remote control to initiate it....
The fellow who repairs Xantrex inverters in Bradenton FL  deals with many inverters and battery banks on the yachty crowds big $$ stuff . (and a poor busnut like me   ) He pushes the monthly method.
the people who listen to him get the longest battery bank life.
I just removed two 8D wet cells that were not equalized monthly ( I don't listen well) but they were done an average every 90 days.
Yes topping off the batteries to insure that liquid stay above the plates before equalizing is a major pain in the @$# but those batteries were dated Feb 2008. 6years is pretty darn good.
Did the frequent equalizing extend there life ? I like to think so...

now I need to relearn what to do cuz I replaced all of my batteries with AGM's....essentially If I understand correctly...AGM batteries are NOT to be equalization charged....Anyone know if this is correct ?

[eagle19952]

PS @ John....you are likely going to be disappointed on cloudy days....right ?

[Seangie]

Mike - here is some feedback for you from my real world experience compared to what I thought I'd need before we started fulltiming 8 months ago -

Before it all began I thought I'd need a minimum of 400 amp hours and a minimum 2000 watts of inverter to change the power from our DC batteries (and alternator while running down the road) to AC power for our adventures.  I was planning on using it to run our induction cooktops, power our laptops, charge our phones and additional lighting and possibly the fridge.  

Realistically I got the aforementioned inverter (previous post) and still haven't hooked up the inverter part of it.  What changed is that I mostly have everything we need to boondock running on 12v power.  All our lights,  fans, refrigerator, phones, laptops are setup to run on 12v power.  I have 2 deep cycle marine batteries with 115 amp hours each from Costco that will get us through 24 hours.  If we need heavy power (for AC or heat) we run the generator.  Sometimes we will run the generator to cook breakfast when we boondock and that typically is when we are charging the batteries.  Lunch when boondocking is usually sandwiches, salad or fruit and we will typically grill out for dinner or go out to eat.  We spend a good bit of time in libraries, coffee shops and McDonald's to do school work (with the kids) and my real work so our laptops are charged when we get back to the bus and all 3 laptops will run for 2-3 hours on battery or we swap batteries with a single laptop.

So as you see our power needs are a lot less than what I thought they  would be when I first started out with the conversion.  If you have a TV and watch a lot of it and you need the house style 5.1 sound system or want to run heat or AC or microwave/oven on batteries while boondocking then you need a beefy inverter system with batteries to go with it.  We do not have a TV in the bus.

As a side note - I've got our TV in the conversion van on 12v power (using a regulator) and it works great. I plan on installing a sound system in the bus at some point but that will be 12v as well.  I will be spending money in the future for more batteries before I spend more on an inverter.  We also use a cheapo 50$ 400w cigarette lighter inverter to charge the laptops in the cigarette lighter when going down the road and boondocking.

Sean (odessey) has mentioned a bunch of good stuff on electrical in many posts of the past.  One of the best suggestions he has made is to create a spreadsheet listing the devices you will have(inverted and 12v), how much power(in amps) each device will use (convert all your 120v devices to 12v and add 10%) and then how many hours a day you will use each device.  Take that total number of amp hours and multiply by 1.5.  That should be a good place to start for your battery purchase.  After that - think about how you are going to use your inverter - many ways to tie one into an electrical system.  It can get a little intimidating when you start putting it all together.

Best of luck!

-Sean

Ps - The biggest challenge that we have continually had in the 8 months isnt power but rather getting good internet.  Plumbing is second.




Fulltiming somewhere in the USA
1984 Eagle 10S
www.herdofturtles.org

[luvrbus]

Mike, a good place for help in designing your system for your use is Northern Az Wind and Sun they have the load sheets,books,any information needed even down to the wire size, they have a forum there also to answer any questions

[Scott & Heather]

Ouch. My head hurts. Someday I'm paying one of you to install my inverter system. I have a headache just reading this thread.


Sent from my iPhone using Tapatalk. Clumsy fingers may contribute to mistakes.

[mike802]

Thank you everyone for all your knowledge and input, I have learned a lot.

Mike - here is some feedback for you from my real world experience compared to what I thought I'd need before we started fulltiming 8 months ago -

Sean: I looked into the ProCombi series and it sounds like it would serve my needs just fine.  It looks like I would also have to buy a breaker box also.  The 2500 watt Quasi wave is listed for 799.00 has the price gone up that much, or did you get a deal on yours?

[Seangie]

Mike - looks like the price went up.  I got the 2500w pro-combi S pure sine from baymarinesupply.com  for about 600 new.  It looks like he only has the 2500 modified sine now.  He does have a pretty good price on some of the magnum inverters.

Sterling makes a good solid inverter and battery charger.  Keep in mind that the 2500 is Max spike wattage and 2000w is about all its rated for on the constant output.  The Magnums aare solid as well.

-Sean





Fulltiming somewhere in the USA
1984 Eagle 10S
www.herdofturtles.org

[georgemci102a2]

The parallax model 555 converter charger works well for me....George

[Seangie]

Ouch. My head hurts. Someday I'm paying one of you to install my inverter system. I have a headache just reading this thread.


Sent from my iPhone using Tapatalk. Clumsy fingers may contribute to mistakes.

Scott - Ill do it for free.  Just not in Michigan in the middle of January! I love doing electrical.  Some pics coming soon!

-Sean

Fulltiming somewhere in the USA
1984 Eagle 10S
www.herdofturtles.org

[Iceni John]

PS @ John....you are likely going to be disappointed on cloudy days....right ?

Clouds, what's them, here in always-sunny SoCal?   Seriously though, I plan on having three days of battery capacity with careful usage, plus there's my emergency standby generator for when the sun don't shine.   2,000 W of panels should still give a few hundred watts of usable power on overcast days, enough to at least part-charge batteries.   As I plan to stay in the sunny desert Southwest most of the time, I'm thinking that solar will work for me.   If I were somewhere else, no, it probably wouldn't be enough by itself.   We'll see!

John   

[luvrbus]

They make a voltage regulator for the alternators that will do equalization and desulfation as you drive that's all that is used in the marine fwiw