AGM batteries purchased too soon

[earthling]

Hi all,  I purchased 2 AGM 200AH batteries in March (yes, 2018) and have yet to get my solar installed...they were sitting in my (HOT) garage in the foam insulated & double cardboard delivery box (in AZ) until last week which was not the original plan...at any rate, I do have them in my A/C'd trailer now but don't have solar installed as of yet and it may be another couple of months...(((heavy sigh))). 

Question is, how do I test them and what do I need to do to keep them from completely draining.  They are hooked up to no-thing.

Links to what I need to purchase (reasonably) to do this would truly be helpful

Thank you <3

 

[DanoT]

If your batteries are in an air conditioned trailer than you must have electricity, so why not hook up your batteries to a battery charger?

 

[John61CT]

Just give them a good charge to 100% Full as measured by endAmps, about every 2-3 weeks.

Only leave on a Float charge if you really trust tge charger.

Talking mains power, you need one anyway.

 

[earthling]

If your batteries are in an air conditioned trailer than you must have electricity, so why not hook up your batteries to a battery charger?

Thank you, do you recommend a certain type?  I haven't a clue what to get.

 

[John61CT]

What model batteries, how many, what voltage.

Float means lower voltage than charging, after Full, to prevent self-discharge.

Cheap garage style chargers can ruin an expensive House bank.

A good charger usually cost more than the bank, but the latter are a consumable, former should last decades.

 

[earthling]

There are two - Renogy 12 Volt 200Ah Deep Cycle Pure GEL Battery

Oh boy, I feel like this is a money pit...thank you for your help

 

[John61CT]

You left out voltage, serial 24V or parallel 12V?

Did you think solar-only would be enough?

For detailed charging profile info, see if you can find links to post for the tech manual, or at least detailed spec sheets.

Do you know who actually manufactures these?

I'm sure you paid a lot more than $1 / AH for them, will want to make them last.

Good news is that good GEL properly cared for can go 5-8 years or longer, more than AGM.

Just not as robust as FLA, GEL batts are very specialized, fussy in their care requirements, life easily shortened and only a couple makers in the world make good ones.

 

[earthling]

My bad, I was calling them AGM instead of GEL.    I bought 2, 12 V that will be in parallel (I was thinking) and honestly am green at this and was watching a lot of videos on YT so got these to go with the 400W Renogy kit...  I also read somewhere in the forum that you should buy 1 watt per solar panel watt (excuse me if I don't have terminology clear "YET", that's what I'm here for, to learn...).    These are RENOGY brand so assuming they mfg them(?) I thought I was answering all your questions(?)  guess not...but thanks for your help.  I'll contact Renogy for charging info. 
Blessings to you brother.

 

[John61CT]

There are very few actual manufacturers, a **huge** capital investment.

99% of brands just put a label on, and can change the outsourced manufacturer anytime. Most of those use JCI, but I doubt JCI do GEL.

Likely Deka, who have good documentation and tech support.

Contact them to get the detailed charge profile specs, google and learn about taking proper care.

Meantime while stored just keep them isolated, charged at 100%, cool as possible.

 

[John61CT]

So for GEL 400AH @12V

ProNauticP is my reco for a mains charger.

60A is a good size.

Sterling ProCharge Ultra, Victron, Magnum are also great.

Avoid Xantrex.

 

[earthling]

So for GEL 400AH @12V

ProNauticP is my reco for a mains charger.

60A is a good size.

Sterling ProCharge Ultra, Victron, Magnum are also great.

Avoid Xantrex.

Thank you for the advice, it is greatly appreciated

 

[Trebor English]

Copy / paste from the Renogy web page:

Cycle charging Voltage: 14.2V(-24mV/°C) at 25°C
Recommended Maximum Charging Current: 40A  

Gel batteries can be very good.  They used to be sold as drop in replacements for flooded lead acid batteries and got bad reviews.  The difference is that gel batteries have the electrolyte immobilized so it won't spill.  When flooded batteries are charged hard they make bubbles and the bubbles float to the top.  Gel batteries with immobilized electrolyte have the bubbles immobilized too.  That makes the plate area covered by bubble no longer functional with no electrolyte contact.  

The valve regulated pressure in the battery causes oxygen and hydrogen recombine.  Before the bubble actually forms the oxygen and hydrogen recombine and there is no problem.  That only works until the charging is too much for the pressure available.

Key point: Don't charge more than specified to avoid bubbles.  The recommended 60 amps will be ok with two batteries parallel connected.  Just one battery rated at 40 amps might not do well with 60 amps.  Accidental or unintentional charging of only one battery at 60 amps counts the same.  

The ProNauticP pdf file uses the words charging and conditioning the way others use the words bulk and absorb.  They do also use the word equalize as distinct from conditioning and typical of the use of that word.  They have two gel charging profiles with conditioning/absorb voltages of 14.0 and 14.4.  Be careful with the set up choices.  There are bad choices available.

 

[John61CT]

But they also give completely custom setpoints as an option, just like sister unit Sterling Ultra

 

[MrNoodly]

Does anyone know the typical time a deep cycle battery spends between manufacture and purchase?

 

[John61CT]

Varies very widely by geography and distribution.

I've seen well over a year, and less than a month.

Doesn't matter much if the outlet is conscientious about topping them up, but the big shops generally don't.

 

[tripper]

If you are not actually using them, just get a cheap 1 amp trickle charger. Plug them in for 24 hrs once a week and they will be fine, Like $15 for some decent ones on Amazon, read the reviews.

 

[earthling]

If you are not actually using them, just get a cheap 1 amp trickle charger. Plug them in for 24 hrs once a week and they will be fine, Like $15 for some decent ones on Amazon, read the reviews.

Hi, I'm just getting back to this...awe, life happens, doesn't it

Thank you for your post.  I need to clarify that these are Gel batteries (not AGM that had posted the wrong info in the thread subject title).    I'm still in sticks and bricks (in HOT AZ) and have these two batteries in the trailer, just sitting (as you gathered already) with the A/C going (the trailer is using shore power).  I have not been able to contact the actual mfg (Renogy will not give me that info, they say they are not allowed to...hmmm?)   I have not gotten solar installed yet because I was doing some mods on the trailer interior first...hired ppl to help, prepaid one person (she needed tires really badly for her Van/Home to get to me from So AZ), she did half the (interior paint) job with the promise of returning to finish and ...guess what?  2 months later, I've not heard from her and the guy that was doing the carpentry (who is friend) also lives in So AZ and needs $ to travel back and forth and I'm just getting burnt out on this money pit (i'm a bit discouraged).  So!  Long story short, I  don't want to make anymore costly mistakes if I can help it (no doublt).  What I  really need is a solar installer/carpenter in the PHX local area soon (before the end of Sept when my lease ends....I  will start a new thread)...I have asked before on this forum and have received some responses but it just never "Gel-d" lol.    I also want to seal the roof before I get the solar up there bc there were previous leaks that the prior owner says was repaired (he was an RV repair guy)...Since it's been storming almost nightly recently, it's held up (thank goodness!)  but the humidity is over 60% inside now due to the storms and I'm just hoping that that doesn't cause an issue anywhere.  I can't just open a window or door because the batteries are in there ...talk about a catch 22.  I have cracked a roof vent very slightly and that will bring down the humidity about 8 degrees, then have to make sure I close it before the next hell rainstorm hits (not complaining about rain in AZ, honestly)...  Just a sidenote (and excuse I guess),  I am in my 60's and have no skills...I worked at a desk my whole life.  Thanks for your advice and lagain sorry about venting here.  Be well

 

[earthling]

Copy / paste from the Renogy web page:

Cycle charging Voltage: 14.2V(-24mV/°C) at 25°C
Recommended Maximum Charging Current: 40A  

Gel batteries can be very good.  They used to be sold as drop in replacements for flooded lead acid batteries and got bad reviews.  The difference is that gel batteries have the electrolyte immobilized so it won't spill.  When flooded batteries are charged hard they make bubbles and the bubbles float to the top.  Gel batteries with immobilized electrolyte have the bubbles immobilized too.  That makes the plate area covered by bubble no longer functional with no electrolyte contact.  

The valve regulated pressure in the battery causes oxygen and hydrogen recombine.  Before the bubble actually forms the oxygen and hydrogen recombine and there is no problem.  That only works until the charging is too much for the pressure available.

Key point: Don't charge more than specified to avoid bubbles.  The recommended 60 amps will be ok with two batteries parallel connected.  Just one battery rated at 40 amps might not do well with 60 amps.  Accidental or unintentional charging of only one battery at 60 amps counts the same.  

The ProNauticP pdf file uses the words charging and conditioning the way others use the words bulk and absorb.  They do also use the word equalize as distinct from conditioning and typical of the use of that word.  They have two gel charging profiles with conditioning/absorb voltages of 14.0 and 14.4.  Be careful with the set up choices.  There are bad choices available.

Thank you so much I'm getting back to this battery thing, had some hiccups...thank you again, I appreciate your response so much, esp the Key point... Best wishes from AZ