Anyone using Odyssey batteries?

PNjunction

A few months ago I started testing a small range of Odyssey batteries with solar (including Sears DieHard Platinums and Hawker-Genesis Cyclons), and wonder if anyone else is using them, and what their experiences are?

The price of admission seems high according to their manuals, with a minimum of 0.4C to recover from an 80% DOD, and perhaps 0.3C for a 50% DOD. This means a pretty disproportionate ratio of large panel wattage to smaller battery capacity than say the norm with other agm's that have far lower minimum requirements.

While I like the nearly unlimited inrush current charging, to do so my batteries are small (like their motorcycle-sized PC535 / PC625) with my 140 watts of panel. My loads are radio hobby loads, so they are not critical - although I did do some homework beforehand to size them according to my current draw and solar insolation and I never go below 50% DOD. I have less than 60 cycles on each, so I don't think I've killed them yet - despite testing with some automobile type agm chargers that regularly hit 15.5 to 16 volts - but only after absorb. According to the manual, this high voltage immediately voids the warantee. Fortunately, I haven't seen any catastrophic failures, gassing, or thermal runaway. But to be sure, I still play it safe with constant monitoring during charge.

Sure, I've wasted half my money using dual-purpose design for my sole deep-charge needs, but so far so good - keeping my fingers crossed. Who know what will happen in the next ten cycles? Does anyone have any longer-term experiences with the Odysseys and solar - especially if running less than the recommended minimum of 0.4C of charge current? Has anyone witnessed the "walking down" of capacity when doing so?

stephendv

Re: Anyone using Odyssey batteries?

Do you have a link to the manual which specifies 0.4C as a minimum? I've rarely seen minimum charge mentioned in battery manuals. Slower rate = longer charge time, and usually slower is better because you don't generate too much heat.

niel

Re: Anyone using Odyssey batteries?

actually, concorde recommends .2c for their sunxtenders. even this rate is somewhat impractical to reach with solar even though not impossible reach. i have 416ah capacity for mine and i can't see them expecting me to put 83.2a from pvs to them. think about this a second as the usable ah is half of the capacity or in my case 208ah and 83.2a from pvs is 40% of my usable capacity. maybe if pv prices continue to plummet then it may be more commonplace to see higher charge rates from pvs to accommodate such charge requirements, but .4c is ridiculous. as it is it is being fed 50a from my inverter/charger or close to a c/8 rate. adding pv to the inv/chgr's 50a can up it to the .2c rate as i'd need another 33.2a to achieve that. i don't have that much capacity in pv to do that and even at that i need to properly mount some of what i have now as it is.

PNjunction

Re: Anyone using Odyssey batteries?

Both the owners manual and the technical application manual can be found here. They are pdf's so I won't put a direct link to them, but they are easily scrolled down to:

http://www.odysseybattery.com/literature.html

The owners manual comes with most of the batteries, and the 0.4C minimum requirement is listed pretty quickly. It is at the C10 rather than the C20 rate, but in practice both are very close. The technical manual goes into much more detail, and the requirement is listed on page 15.

For the most part, I've been following the typical IUU profile, although if you ask the engineers at Enersys (or dig up earlier tech manuals), they provide an alternative IUI charging profile, much like the Rolls agm's do, where an elevated 15+ volts is applied after absorb, for applications requiring 16hours or less of charging. (this is not en equalizing charge, but very low current). I've done it both ways with chargers, and even emulated it with a Xantrex pwm CC that had programmable absorb and float voltages.

The reason I'm also experimenting with chargers as well as solar is thinking that maybe once a week or two, I'll hit them with an ac powered charger that meets this requirement when my solar output is barely meeting the requirement just to keep them in shape - kind of like the marine guys do.

PNjunction

Re: Anyone using Odyssey batteries?

niel wrote: »

actually, concorde recommends .2c for their sunxtenders. even this rate is somewhat impractical to reach with solar even though not impossible reach.

You may want to ask the Concorde engineers at what DOD does this .2C rate apply? I lost the link to what appeared to be a legit response from an Enersys engineer stating that for the Odysseys, if you only draw down to a 50% DOD, then 0.3C is ok, and 0.4C was for a super deep discharge of 80% DOD. Perhaps in Concorde's case, the minimum requirement would be even lower than 0.2C if you never go deeper than 50% DOD....

It just scared me that if you don't supply the minimum, you'll be slowly walking down the capacity. Problem is that I don't know how fast or how bad this loss of capacity would be over the normal lifetime of the battery. Are the engineers talking about huge losses, or just small lab results that in the real world may not be an issue if the battery dies of old age first..

niel

Re: Anyone using Odyssey batteries?

it was only in the last few years that i became aware of that .2c requirement when somebody pointed it out to me inb the tech manual, but i had a pvx1040 since 2003 and did smallish chargings on it for most of its lifespan (between 3a and 6a typically from pv and 6a from an auto type ac charger upon occasion) (8 good years with some occasional abuses from me). it quit about this time last year from being able to hold as per the 80% capacity concorde specifies before it needs replacing. i still have it and it is nosediving on the capacity.

i can't say if it would've done better with a higher charge, but i know i popped the vents a few times too as my controller was kaput and i needed another. i overvoltaged it quite a few times and literally heard the soft puff of that vent opening and you had to listen for it as it's not like the old bottle cap openings on your favorite beverages of decades past.

Cariboocoot

Re: Anyone using Odyssey batteries?

If that charge rate is being written correctly it's not what you think. "0.2C" should mean two-tenths of the capacity. In other words every 100 Amp hours of battery capacity gets 20 Amps of current. There's nothing spectacular about that, unless that's the upper limit. In which case I'd suggest getting better batteries.

stephendv

Re: Anyone using Odyssey batteries?

Well I'll eat my hat now. It looks like about 40% of rated Ah as a minimum. They also have it stipulated in a table on page 15 of the manual, e.g.:
40A for a 100Ah battery

Chalk that one up to "weird-agm-stuff"

http://www.odysseybattery.com/documents/US-ODY-TM-001_0411_000.pdf

PNjunction

Re: Anyone using Odyssey batteries?

I'm hoping that my experience will be similar to niel's - maybe a regimen of ac charging once in awhile, and kind of forcing myself to not go past 25% DOD. For small low-current projects and limited solar-insolation it works great! On a bigger scale, the cost of panels / chargers needed and panel real-estate could become a limiting factor.

Great batteries so far, but for anything but smaller scale stuff, think twice - you've definitely got a major solar infrastructure commitment to come to grips with.

niel

Re: Anyone using Odyssey batteries?

coot,
that is supposed to be the minimum charge. for one 100ah battery 20a is no sweat. i have 416ah in capacity here now and i can't feed them 80a. they are efficient in their charging so i have little fear of detracting much from cycle life by going lower on the charge. the high bulk rate they call for would not be present for too long on the batteries and from there would taper on absorb so i look at the bulk as a lower voltage higher current prolonged absorb. i know, no such animal, but you get my point i hope.

mtdoc

Re: Anyone using Odyssey batteries?

Well, IMHO the 0.4C10 charge rate is a big fat red herring. Yes, I have Odyssey batteries - 436 AH at 48V worth.

A couple of things when reading over their extensive technical manual that you have to keep in mind - (and I've read it so many times I've practically memorized it).

Odyssey batteries, while having pretty decent deep discharge characteristics were never designed for RE applications and the technical manual is not written with RE in mind. I believe the original design by Enersys was directed at mission critical type military starting applications (Tanks, Humvee's, Jet's, etc) that also see occasional deep discharges. They can crank out very high amps and be recharged very quickly (3+ times C!) without damaging them. They can recover from being 100% discharged and have very low self discharge rates. They can withstand a lot of physical abuse as well. These are the characteristics most needed for the application they where designed for . In addition to military applications, they are most commonly used in high performance motor vehicle applications. (Racing cars and boats)

The technical manual is written with these kind of applications in mind. So recomending 0.4C10 bulk charging rate is because that is going to get them through bulk charging quickly and they sell a whole line of chargers designed to do this. Most of the people using these batteries are plugging a charger into the grid and are using only one 12 volt battery in one of the smaller AH varieties - so charging at 0.4C10 is no big deal.

They never specifically say that bulk charging at a less than a 0.4C10 rate will damage them - just that undercharging them will shorten their lifespan (as is true for all lead acid batteries). Have a close look at page 16. Specifically they state

Effect of undercharge in cycling applications
Proper and adequate charging is necessary to ensure that
ODYSSEY batteries deliver their full design life. Generally
speaking, a full recharge requires about 5% more amphours
(Ah) must be put back in than was taken out. In other
words, for each amp-hour extracted from the battery, about
1.05Ah must be put back to complete the recharge.
Cycling tests conducted on an ODYSSEY PC545 battery
demonstrated the impact raising the charge voltage from
14.2V to 14.7V has on the cycle life of the battery. The
results are shown in the graph below.

They go on and discuss using an ideal end amp value (0.001C10 !!) or absorb time (8 hrs!) before going to float.

Table 5 shows the suggested charging times of a 100% discharged battery with different amp chargers.. For the PC1800FT (what I have) which is a 218AH (C20 rate) battery they suggest 17 hours of charging with a 20 amp charger! In other words - a charger that is only supplying 0.09C20 which is no where near the 0.4C10 rate they mention earlier (and just about what one wants for a typical solar install).

In the end I think it's important to remember that they are just a variation on traditional lead acid AGM batteries. The chemistry is the same. As long as you don't undercharge them or leave them for extended periods at a low SOC, replace the amps you take out (plus charging efficiency losses) and charge them the the correct voltage levels then there is no reason IMO that they shouldn't meet the cycle life characteristics they show you in Figure 1 on page 11.

It just so happens that they can also withstand 700 cycles at 50% DOD. Because of of this and all the characteristics discussed earlier, they have become popular in other demanding applications that can benefit from these qualities: Boaters who do extended offshore cruising (and often charge with solar), Electric Vehicles and battery back up applications where they are used in large banks, deep cycled and unlikely to ever be bulked charged at a 0.410 rate!

While not designed for RE applications they do make a good choice for hybrid systems IMO. They are not a good choice for someone who deeply discharges them every day. If you're doing that and want a long lifespan you're best off with a fork lift type battery any way (and accept the higher maintenance, poor charge efficiency and high self discharge characteristics).

While I've only had mine for year and a half, in the dozen or so times I've deeply cycled them, I've had no problems bulk charging them at a 0.07 to 0.10 C 20 rate. Their high charge efficiency and ability to crank out a lot of amps very quickly to power the inrush demands of my Septic pump have been appreciated.

Sorry for the long winded rant - just opinions of course, (but based on facts:-) ) In another 5-10 yrs I should be able to tell you first hand about their extended lifespan when never charging them at 0.4C10 !8)

niel

Re: Anyone using Odyssey batteries?

i believe i agree with you in all respects here. i do find the absorb down to .001c to be a bit over the top though as that is about a float charge imo and even those batteries i'll bet will be higher than .001c when the float is cycled as many ccs and inverters do. they are saying 9hrs bulk charge and 8hrs absorb charge. we usually don't absorb charge to that ridiculously small current level, but in retrospect the sunxtender is supposed to be to .5a/100ah of capacity or .005%, but it is still 5x as high as their spec. other fla types often list 1a or 2a for end amps (absorb). 8hr absorb charges are definitely not conducive to solar.

it makes me wonder if they list an absolute max charge rate for their batteries.

PNjunction

Re: Anyone using Odyssey batteries?

I've memorized the manuals as well. For even more fun, realize that the Odyssey is a brand-name under the Enersys flag, like Genesis agm's in their reserve power division. Check out these models of Genesis along with the technical manual, and you'll immediately recognize it. Thing is, the brochures and whatnot suggest use for solar, and even have a pic of a panel setup. Take a look at the Genesis XE line:

http://www.enersysreservepower.com/productDocuments.asp?id=100&brandID=3

In fact, that is what I stumbled across first before I found a local Odyssey dealer. Then I discovered the diehard platinums being rebadged, so I jumped and satisfied my immediate-gratification and local community support desires in one go.

What they are saying seems to be true - I purposely bought a 3-year old shelf-queen (the 535) sitting at 12.5 volts (amazingly), and only two cycles brought it back to full capacity - although this is a year beyond the normal worst-case storage. Must have been stored cool, but even so, that kind of low self-discharge blew my mind. I have subjected it to abuse on purpose (personal safety like thermal monitoring attached) and overcharged it up to 17.5 volts many times and survived, killed it twice to only 9v oc and revived it, and while I'm sure that took it's toll in overall cycles, that led me to my next one, the 625 which I'm taking care of nicely. I haven't put too many cycles on the diehard-platinum (similar to the PC1200), but I will treat that one nicely too - knowing that they will take accidental abuse.

So perhaps solar isn't the marketing demographic for the Odysseys, but the sister Genesis XE is. These tppl's seem to be wrapped up in different packages, yet pretty much the same thing underneath. I guess I'm just going to put Enersys to the test to see if their deep-cycle claim is true. So far, so good.

mtdoc

Re: Anyone using Odyssey batteries?

niel wrote: »

i do find the absorb down to .001c to be a bit over the top though as that is about a float charge imo and even those batteries i'll bet will be higher than .001c when the float is cycled as many ccs and inverters do.

Ha - yeah 0.001C is very over the top. For my system - since i use measured end amps from my FNDC to determine when to sell power (and thus just keep my batteries at float) - I found that by plotting return amps over time during absorb (using WattPlot)- I could empirically find where the curve of decreasing amps become asymptotic and use that value for my end amps - which turns out to be about 1% of capacity in AH or 0.01C20. Though I've done it, trying to get to 0.001 C every day would be crazy.

PNjunction wrote:

So perhaps solar isn't the marketing demographic for the Odysseys, but the sister Genesis XE is. These tppl's seem to be wrapped up in different packages, yet pretty much the same thing underneath.

Yes indeed Enersys made batteries are marketed under many names. In fact we recently discussed on this forum the fact that THESE Outback branded batteries are likely made by Enersys since their form factor is almost identical to the Odyssey PC1800 FTs.

It's interesting that the technical manual for the Genesis XEs has almost identical word for word info as the Odyssey technical manual except that they omit the part about bulk charging at 0.4C ..:roll:

PNjunction

Re: Anyone using Odyssey batteries?

It's interesting that the technical manual for the Genesis XEs has almost identical word for word info as the Odyssey technical manual except that they omit the part about bulk charging at 0.4C ..:roll:

That's a GREAT catch - I missed that. This is quite significant. While I enjoyed how thorough the application manuals are, after reading them so many times it made my head spin, in the end it almost appears to be a way to close all the possible loopholes for those trying to get free battery replacements for life. Indeed, while I was purchasing my Diehard Platinum, a guy was causing a ruckus trying to get a free platinum replacement because it was only 8 years old, and couldn't even supply how it was charged over its lifetime. He walked away empty handed - well maybe with 40 pounds of dead weight. I do see where in the Genesis application manual, they just recommend using the highest possible current from a practical and financial standpoint.

There's no way I'm going to be able to supply .001C for 16-20 hours float in my solar setup either to meet the warranty requirement.

Interestingly enough, my rebadged Odyssey, aka Diehard Platinum also looks exactly like a Hawker MILPC battery - only a few ah different capacity, but the case is exactly the same. Even went back to 1998 Hawker application manuals, and they also suggest solar use without mentioning a 0.4C minimum. I really wanted to go back to 1977 Gates manuals, but no luck finding those.

Unless I'm missing something major, my guess is that the 0.4C minimum is a way to ensure that batteries marketed to the motive power industry like Odysseys don't end up deficit-cycling the batteries at say a 50% DOD all the time, and the high minimum is to help ensure a decent SOC for short daily trips ... man, I hate having to guess or try to read between their lines in the manual. Perhaps there is hope for us solar guys that only take the DOD down to 25 or 50% max with relatively low current for recharge. Guess we'll find out.