Is this AGM brand any good?

kcarsey · 01-18-2019, 08:07 PM

Looking at different AGM battery brands and sizes.

I'm looking at 500-700Ah total capacity. I've added up my total usage over 24 hours and it's looking like around 161Ah worst case, likely lower.

Does anyone have any experience with this brand of batteries? Looking at two of them in parallel for 500Ah total.

https://www.wholesalesolar.com/99250...8d-agm-battery

If not, any other reasonable price/quality recommendations? I like this style of battery because they aren't tall and should be easier to stash inside the bus. I plan on storing them inside for a more consistent temperature/capacity. I'll likely be in areas with freezing weather, and also hot weather so for me keeping the bank inside seems to make sense for me.

I'll likely put them in a stainless steel enclosure made by the local sheetmetal shop, that's vented to atmosphere, just for an extra safety margin. Is this overkill/not needed with AGM? am I just being paranoid? Real experience appreciated.

john61ct · 01-20-2019, 07:01 PM

For NA market, assuming for deep cycling use Odyssey, Lifeline and Northstar.

Tango · 01-20-2019, 07:56 PM

All good brands. Sadly...Optima, which used to top many peoples lists, has gone in the toilet since they moved production to Mexico. Horrible reviews for the past few years. Bummer. One more good product destroyed by some narrow brained bean counters.

EastCoastCB · 01-21-2019, 05:48 AM

Quote:

Originally Posted by Tango

All good brands. Sadly...Optima, which used to top many peoples lists, has gone in the toilet since they moved production to Mexico. Horrible reviews for the past few years. Bummer. One more good product destroyed by some narrow brained bean counters.

That sucks. I had an optima long ago. It was really great although it did weigh a whole lot.

kcarsey · 01-21-2019, 08:23 AM

Quote:

Originally Posted by john61ct

For NA market, assuming for deep cycling use Odyssey, Lifeline and Northstar.

I was referring to house batteries for deep cycle. I've heard of Odyssey but always considered them sort of a high end dual purpose or high end starting battery. Sort of a top of the line AGM alternative to a standard auto starting battery. It seems they don't offer real large capacity AGM models. I was hoping to find something 200+ Ah. and do 2-3 in parallel. Less batteries I have, the less batteries I have to worry about staying in balance.

Did a quick search for Northstar, and seems like sort of the same story. Some school buses come with them from the OEM. I suppose i'll do more research.

A lot of the brands for solar seem to have many options. I guess something I should think about is that a lot of the "stationary" solar batteries are ment just for that.. stationary use. Use in a moving, vibrating vehicle would probably be a factor to choose a more "mobile" friendly battery.

john61ct · 01-21-2019, 09:42 AM

No, those are the best, really the only good quality deep cycling AGMs in the N.A. market.

Firefly is specialist, Full River OK but not as good.

And quality + capacity always means heavy with lead. LFP is lighter but 5-7x more.

FLA is **much** better value.

Sure you really need sealed?

PNW_Steve · 01-21-2019, 09:47 AM

Quote:

Originally Posted by john61ct

FLA is **much** better value.

Sure you really need sealed?

I agree.

I would also recommend that, for the bank of that capacity, that you weigh the advantages of a 24 volt or 48 volt battery bank.

PNW_Steve · 01-21-2019, 09:58 AM

There are some pretty sharp folks over on Forums - Solar Panels - Solar Panels Forum who have written some great stickies that are relevant to your project. Here are a few of them:

https://www.solarpaneltalk.com/forum...-size-tutorial

https://www.solarpaneltalk.com/forum...utorial-part-2

https://www.solarpaneltalk.com/forum...s-why-tutorial

https://www.solarpaneltalk.com/forum...battery-design

https://www.solarpaneltalk.com/forum...ry-connections

kcarsey · 01-21-2019, 10:05 AM

I don't have the budget for any lithium type battery, although I wish I did.

My inverter size will be 2000 Watts which should put me no more than peak ~166 amps. Figure 250 for a safe margin. I won't have any "hard start" appliances. no a/c units or anything like that. My biggest power user will be a microwave, or my wife's hair dryer. Maybe an angle grinder or other small hand tools if work need to be done on the bus. The hair dryer is the main reason i'm going 2000w instead of 1000w inverter.

I'd like to stay 12v in order to operate fridge, lights, etc and also charge with a 12v alternator. and avoid needing a 24-12 converter. Also if the need arises I could start the bus from the house bank in an emergency.

I should also add that I have the tools/means to have the proper cabling for high current. I used to work with dc power at colo and cell phone sites. I have proper Greenlee crimpers, ends, etc to be able to put it all together with the proper cable.

As far as battery style, i'm not totally locked into AGM. I could probably save quite a bit of money going with FLA. If i'm going to go to all the work to build a proper vented enclosure inside the bus, I might as well save some cash and go FLA, as long as I am able to access the batteries for maintenance.

If I do go FLA, should I look at the same brands? I have done research and there are tons of battery makers and I realize not all are created equal, and two types of "deep cycle" battery may not be built the same. Some are designed as "standby" use and not ment for daily cycling, at least so i've read.

I don't have an exact number on rooftop solar, but i'm going to put as much up there as I can fit. I'd say 1.2kw, but probably more. If I can fit 6 ~300w panels that'd put me at ~1.8kw which would be ideal to have enough charge current for those batteries to be happy. My bank sizing is really just revolving around not going over c/2 or ideally c/4 discharge rate at peak usage, which again will be limited to a hair dryer running for 5 minutes, or a microwave running for 5 minutes, etc. 750Ah / 160 peak amps puts it around c/4.6 which is good.

I've checked out the frequently posted thread here from solarpaneltalk and it has a good bit of info, some of what I have here was gathered from there.

Edit: @pnw_steve just saw your post with the threads over at solarpaneltalk.com

PNW_Steve · 01-21-2019, 10:18 AM

Trojan, Crown, Rolls....

Myself, I will have a similar capacity but a little different configuration. 4 Crown CR370 batteries in series for a24v/370ah battery bank.

I found most everything I need in 24v. Pairs of LED (12v) lights will be wired in series to function on 24v. USB chargers, water pump etc are available in 24v.

I guess that's why we are all here

None of us wants what someone else decides we should have in our rolling home. We want to build to suit what each individual wants.

Good luck.

kcarsey · 01-21-2019, 10:33 AM

Thanks for the insight everyone. I'm not ignorant enough to think I should do things any particular way just because "it's my way" haha. I appreciate all the input, even though I know batteries/solar,charging/etc have been beat to death, sometimes it's still helpful to have fresh eyes on something. Maybe i'll just take a look at 24v alternators for my charging also. They don't seem too hard to come by.

And you are right that most fridge are 12/24v. lights aren't a big deal. I'll have some relays/control equipment that will need 12v that I can use a down converter for. I also plan on having a few 12v "cigarette" sockets throughout to charge phones, ipads, etc. I'll only be using my inverter when I need it, so it'll be powered off at night. but heater, etc would run on 12/24v.

john61ct · 01-21-2019, 10:40 AM

The best battery value by far is Duracell (actually Deka/East Penn) FLA deep cycle golf cart batteries, 2x6V, around $200 per 200+AH @12V pair from BatteriesPlus or Sam's Club. Deka labeled same batts also sold at Lowes.

The other quality makers of FLA in the NA market are

Rolls/Surette, Trojan, U.S. Battery, Crown, Superior

Nothing 12V sold retail is acually deep cycling quality, fraudulent use of that term and "marine" are the norm.

john61ct · 01-21-2019, 10:42 AM

The little savings in copper from going higher voltage are IMO offset by added complexity and the need to convert back to 12V.

KISS

PNW_Steve · 01-21-2019, 11:11 AM

Quote:

Originally Posted by john61ct

The little savings in copper from going higher voltage are IMO offset by added complexity and the need to convert back to 12V.

KISS

There is much more to it than just being able to use smaller wires.

Again, we are all here because we want to build it "our own way".

If you really want to spend as much as you possibly can on batteries over the life of your system then you should probably parallel a bunch of 12 volt AGMs.

Best wishes on your success.

kcarsey · 01-21-2019, 12:38 PM

Thank you all for the seemingly strong opinions either way. I'm not sure why I was so stuck on 12v only system before, but cost wise there's really no difference to change to a 24v system and it brings a lot of advantages and in some ways simplifies things. I'll take a closer look at just going 24v instead of 12v. The reality is basically everything I want to run can all either accept 24v, or has a 24v model. Fridge, Espar hydronic 10, blowers/fans, etc.

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