Odyssey AGM and solar experience?

[Sunking]

On a related note about charge currents for the Odyssey ...

Odyssey says that the minimum bulk charge current for their tppl batteries is .4C - but I had always wondered if going lower would be doing harm. It isn't always perfectly sunny during my charge periods to get the max out of my panels.

PN I think you are missing or overlooking something. Odyssey batteries and many like them are not manufactured for renewable applications. Trying to use them in such applications is a misuse of the product. Case in point Odyssey products target markets are automotive and marine. Your other battery you have is intended for the commercial UPS market.

AGM batteries made for the Renewable Energy market for the most part only limit the maximum charge rate which can be applied to them, and there is no specified minimum charge rate. In a properly designed RE application the charge rates will vary as low as around C/15 in locations with high amounts of solar insolation like Tuscon AZ, and as high as C/3 in Gloomy Doomy Seattle WS. This is why the design process is so critical to be able to match components to work with each other.

How many times have you read post on where where someone just goes out and buys crap and it does not meet their expectations? Just about everyone who comes here asking about solar battery systems right? The answer always boils down to the same thing, IGNORANCE and FAILING TO DESIGN. It is too late when they finally ask for help, and they never like the answer when they find out they threw away a bunch of money and only got about 10% to 30% of what they really wanted.

So far you are fortunate playing with small inexpensive stuff. But what you are playing with is not applicable to what you want to do in the future. You are learning something, but not really applicable to what you want to do. You are basically learning how to do it incorrectly. Might be time for you to turn the corner and do a U-Turn in the right direction. So far you are throwing good money away.

[PNjunction]

PN I think you are missing or overlooking something.

I promise to U-turn. I'm just exploring an offbeat alleyway. I want to get my goofs out before I destroy a nice bank of Trojans and the like.

Odyssey batteries and many like them are not manufactured for renewable applications. Trying to use them in such applications is a misuse of the product. Case in point Odyssey products target markets are automotive and marine.

I guess I felt challenged by Enersys when I see that their identical Genesis XE / XP line states:
"The Genesis XE thin plate pure lead battery excels in demanding environmental and cycling applications such as: Alternative energy applications; eg solar and wind power. Hybrid electric vehicles HEV". Yep- still dual application - dedicated RE would be better. There is even a picture of a solar panel to prove it!

The Odyssey seems like the exact same thing according to their manuals and composition (pure lead - tin) - only marketed to a different demographic. I felt like taking them up on that challenge for a system that will never see a starter switch. Enersys threw down the gauntlet more or less. It's go-time! I don't see any difference, just a different sticker on Odyssey vs the Genesis XE battery.

One very interesting thing is that the XE / XP line says that cyclic voltage is 14.7 - 15 volts! Makes me wonder if the Odyssey's would prefer that as well, or are they making exceptions for the automotive market and the typical alternators with just a simple warning to not exceed 15 volts?!?!

Could this also be the holy-grail of preferred Odyssey voltages in reality? 14.7-15v. That might explain why the Sears Platinum charger I have seems to operate at 14.8-15 volts, which has a selection intended for their rebadged Odysseys.

In a properly designed RE application the charge rates will vary as low as around C/15 in locations with high amounts of solar insolation like Tuscon AZ, and as high as C/3 in Gloomy Doomy Seattle WS. This is why the design process is so critical to be able to match components to work with each other.

Most definitely, and this is a big issue I have with the Odyssey / Genesis line demanding 0.4C minimum with deep discharges (not dead though). Not only is meeting 0.4C impractical from a panel cost standpoint for big systems that might go below 50% DOD once in awhile, just limited panel real-estate could also be a no-go. AND, with very cloudy conditions, pumping low current into one of these may do nothing more than heat things up if it can't overcome that heavy special oxide layer they have, and damage the battery that way with a slow-roasting undercharge. But with the XE / XP line saying it's ok for solar, with only one little picture of a panel, they are saying two different things to me.

Time to contact Enersys I guess and get the scoop on what's really going on between these lines. That XE/XP 14.7-15V recommendation really has me going now...

For the real thing, you can bet I'll be into something like a Midnite Classic, a bank of quality RE batteries, with my loads calculated taking solar insolation into account. Your battery / panel / system selection guides are invaluable.

[PNjunction]

Ok gang, I'm pretty sure everyone is very tired of this thread for powering my 12V toys. I contacted Enersys and I'll see what happens.

One very interesting thing is that the XE / XP line says that cyclic voltage is 14.7 - 15 volts! Makes me wonder if the Odyssey's would prefer that as well, or are they making exceptions for the automotive market and the typical alternators with just a simple warning to not exceed 15 volts?!?!

My last thought is that even though the Odyssey and Genesis XE have different recommended cyclic voltages, it just might be the case that Enersys is trying to protect the average user of an Odyssey with slightly lower voltages due to not having temperature compensation / thermal monitoring for the typical underhood application. That's my speculation. For me, with both protections in place, I'd want a custom charge controller that can go up to 14.8 or so.

I think I've reached the end of my journey with Odyssey. Nice batts to be sure so I'll keep using / testing them until I build up a big RE system.

[Sunking]

I guess I felt challenged by Enersys when I see that their identical Genesis XE / XP line states:

That is a RED Flag warning. Thin Plates mean cranking type battery, not deep cycle.

I will let you do the homework but give you a hint what to look for with respect to lead acid battery voltages. There are 3 types of plates. Pure Lead, Lead Antimony, and Lead Calcium. Each has advantages and disadvantage. Look it up in the Bible.

[PNjunction]

To be sure, when I go serious with RE, I'll be using something like Trojans or Rolls/Surrete.

As for the composition of the plates, I think it goes something like this:

Lead - pure: lowest self discharge - least resistant to shedding.
Lead - calcium: low self discharge - and a bit resistant to shedding.
Lead - antimony: comparatively high self discharge - very resistant to shedding.

TPPL: The pure-lead tin overcomes the shedding due to the materials being about 30% larger than the case itself, and is very tightly compressed during case fitment to make it physically harder to shed. And the pure lead/tin allows for much higher input current than other doping techniques. At least this is what I understand of the Odyssey / Genesis / Hawker / Diehard Platinum line of tppl's.

The Odyssey manual describes the use of Total-Loss (no alternator) racing, so there is some measure of deep-cycle capability - but I have no knowledge on the hit you take on cycle life under those conditions. My low current 12v toys should last much longer.

Side note: Hawker - who makes the military versions seems to have a new charger, "LifePlus TC3-W" which has an interesting charge profile for TPPL that incorporates equalization! However, that box seems totally proprietary, lacks specs in the flyer, and who knows what they really mean by eq for a tppl.

But yes, it is easy to see that the primary application is for vehicle starting.

Argh - you just might make me pick up a smaller Trojan/RE agm to play with now to get a tast of the real thing before I get serious.

[Sunking]

The Odyssey manual describes the use of Total-Loss (no alternator) racing, so there is some measure of deep-cycle capability -

Do not think I would make that conclusion. Tires and engines are disposable items in racing. I would think the battery is a one-time use product.

[inetdog]

TPPL: The pure-lead tin overcomes the shedding due to the materials being about 30% larger than the case itself, and is very tightly compressed during case fitment to make it physically harder to shed.

Since lead is not going to compress much, I have to assume that the compression is all in the fiberglass mat between the plates. It seems that that would also tend to leave less room for electrolyte, require thicker mats to start with, and possibly reduce the ionic mobility of the electrolyte. But if you can get significant compressive forces while still leaving a sufficiently open mat, then it does sound interesting.

And although this may address shedding, I can't see it similarly affecting the corrosion (redistribution of the lead) during deep charge/discharge cycles.
Waiting to hear whether the current issue of the bible adresses the TPPL design.

[PNjunction]

0.4C only needed at 80-100% DOD!

Well - a tip of my hat to Sunking and Inetdog: You guys are making my eyes bleed researching all this stuff. For some reason, I can't get enough of it.

While I won't be building an RE solar system based around tppl batteries, the point is, it can be done - but that 0.4C minimum inrush current is a real pita for most solar users. This old application manual from Hawker in 1998, which goes into greater detail than the more recent application manuals about using tppl batteries in HEV (hybrid electric vehicles) explains it all in a way a dunderhead like me can relate to: (Hawker Genesis Electric Vehicle Application Handbook, 4th ed 1998)

http://www.evdl.org/lib/index.html

Essentially, the 0.4C minimum limit applies if you are trying to recharge a battery from deep discharge 80 to 100% DOD back to life in 6 to 8 hours using the fast-charge profile they describe for a typical fleet of HEV's!! As solar users, we don't go there - at least not intentionally or unless the system was put together with no engineering applied at all. SO, I have no problem designing a small tppl solar system around much lower minimum inrush currents - as long as all the other elements of good solar design are taken into account obviously. WARNING - this document is from 1998, and specifications (and warranty spec claims!) can change over the years.

It also explains why my Schumacher charger didn't make the vents immediately blow - but I'll leave that for another forum.

At least I'm no longer worried about the 0.4C minimum, and in fact will be using more typical 0.15 to 0.2C rates with my temporary tppl-battery solar setup since I won't discharging down to 50% DOD on a regular basis anyway and my solar insolation will meet the need - although I will hit them up with more current when I can. I will be using a line-powered charger for maintenance once in awhile however since I feel that the 14.7v is the true minimum voltage spec to meet, and my little pwm cc only limits up to 14.4v.

Had I just started with a dedicated RE agm, I'd have a few more hairs on my head. I must be crazy to think this is fun - but it is!

[PNjunction]

Got the word back fast from Enersys regarding the difference between the Odyssey and the Genesis XE - they have the same electrochemical design, so performance is the same. I take it that would also now include the Hawkers and Diehard Platinums. I suspected as much but wanted an official word.

Forgot to mention a big difference between the 1998 application manual for HEV's, and the more modern manuals which followed - the modern manuals make no mention of a fast 6-8 hour charge ability with a 15.6v stage following absorption as seen in 1998 - in fact now they prohibit voltages above 15v for any reason. Still, with my unauthorized chargers which immediately voided the modern warranty, the PC525 / 625 didn't cry in pain when they went to 15.5v after absorption for a short time. We're entering an EQ type of voltage here, so I'm being careful to pull the charge when it does happen.

[PNjunction]

Xantrex C12 vs Morningstar CC for Odyssey test

For my small battery / large panel testing, I changed charge controllers from a Morningstar Prostar 15 pwm to a small Schneider/Xantrex C12 pwm. There is a small problem however that is overcome.

The main difference here is that with the C12 I can adjust the absorb / float voltages as well as having a real temperature compensation probe on the battery, (optional, snap-in and recommended!) as opposed to the Morningstar's 14.2/14.4 absorb, and a 13.3v float with ambient temp compensation - .3v too low according to Odyssey. (real optional temp probe on morningstar you solder in yourself).

While the C12 will also do EQ (1 volt above absorb), I can guarantee it is disabled with a jumper (defaults to NO eq), but manually do it if I want to fry the Odyssey for science.

Because I'm cycling daily with limited insolation of 4 hours at best, I'm basically setting it to bulk=absorb=float at 14.5 volts. The Odyssey IUU profile wants 8 hours of absorb before dropping to float, and there's no way I'm going to get that with daily cycling. ALSO, the Xantrex will automatically drop to float after a fixed-period of only 1 hour at absorb with no way to adjust that time. So I compensated with an absorb-matching float voltage due to my restricted time period.

So far so good, and I like the flexibility of the C12. Not too happy about the self-tapping sheet metal screw on the front cover, but it isn't a showstopper. I don't use the load/lighting control options. I'll let you know if I let the smoke out.

P.S. - the sunken led on the front cover is NOT the EQ button. Don't push it in, and be careful when removing the cover for adjustments so you don't bend it. Less coffee helps when unboxing.

[PNjunction]

Two new developments have surfaced that put my mind to rest when dealing with Odysseys, thanks in part indirectly to East Penn and an online statement from Odyssey to an Australian user wondering why their own chargers are not for sale there and one response was to look at CTEK, as long as the user chose one with the proper current level ....

For *optimum* life, an Odyssey needs 0.4C when deep discharged. At 50% SOC, you may get away with only 0.3C. In an automobile application, where you may only temporarily draw less then 10%, then you can get away with the current of the typical automotive alternator. Accidentally discharge it deeper and you'll want a decent charger on hand that can put out some real current.

So if you are doing anything other than SLI service, then you are going to want to have a charger that meets the 0.4C rate. Yes, you can temporarily get away with less, but *over time*, using a smaller amount of current even while charging will lead to sulfation and voids the warranty. Since the batteries are TPPL, if you have a collection of these Odyssey batteries (like I do), then a charger with much higher current capabilities is not a problem since they can take it.

Higher sulfation rates *over time* is also the reason that they specify a minimum float of 13.5V, something I never usually reached while solar, but is the main bone of contention between other charger manufacturers and backyard enthusiasts. It all depends on if you want to stay within warranty, or just buying expensive batteries sooner due to sulfation. In addition, going above or below the recommended temp-compensated float voltage leads to accellerated grid corrosion although doing nothing but just sitting with an open circuit has the highest grid corrosion rate of all.

Since I put my low-current solar-charged Odysseys on a qualified high amperage charger every week or so, I really saw no bad sulfation effects that I could detect.

My East-Penn / DEKA agm battery that I'm working on has a max current limit of 0.3C. It is NOT tppl, but lead-calcium. The good thing here is that one sentence from their tech manual states that for the longest life, one should try to charge with the largest amount possible not going over the 0.3C limit. This kind of reiterates what Odyssey is saying, although being lead-calcium, the MAX for the Deka is 0.3C. In essence, don't tickle an agm to death!

So here, yes, you can get away with less current for awhile, but it is not beneficial in the long run. If using these for solar applications (yep - they are dual-purpose hybrids, not real RE batteries) where the charge current does not meet Odyssey's minimum, (or perhaps in Deka's case being close to the max limit), then throwing them on a charger that meets these specs might be a good idea once in awhile.

[Naptown]

Look at the minimum and maximum charge rates from the battery manufacturer. I suspect .4 is max charge rate

[thastinger]

I have a PC535 in my ATV, it has lasted for years getting shaken to hell but I seriously doubt my factory stator is capable of charging it at 7.5 amps.

[Sunking]

Look at the minimum and maximum charge rates from the battery manufacturer. I suspect .4 is max charge rate

Point of interest Odyssey does not make a Deep Cycle battery. They make Marine Hybrid batteries which will have about 400 to 500 cycle life which is not what you want from an RE battery. .4C is max charge rate. Since it is AGM you can charge as slow as you want.

The selling point of Odyssey is very low internal resistance which means they can deliver very high charge/discharge currents which is great for electric vehicles. but of no real use for RE application. Well unless you are an idiot and have a 12 volt 1000 watt inverter in your home. OK for work trucks, boats, and RV's with battery isolator working with vehicle alternator.

[Sunking]

Got it. Is there another battery that's around 20Ah (AGM) that would give me more room to charge higher than .4C? I don't plan on running anything A/C off of this.

To many to shake a stick at. Power Sonic has many to name one manufacture. You are talking motor cycle and E-bike very small size. Just keep one thing in mind with AGM you are border line Hybrid and will give up cycle life. Top of the line AGM is Concorde Sun Extender AGM like a 340T which is a little larger than you are looking for but should give you 1000 cycles with extremely low resistance.