Battery Bank - Lead Acid or AGM?

[McPuccio]

6x 6v 190AMP AGM for $280 ea for $1600

OR

4x 6v 260AMP Flooded for $184 ea for $800


Pros - AGM over Flood
- No maintenance
- No need for venting

Pros - Flood over AGM
- Cheaper
- Virtually the same amp hours



Hard to see why I would go with AGM tbh but a lot of people we've talked to go with the more expensive option.

We will be living where it gets down to low teens, might leave our bus for a month or two here and there for car trips.

Venting isn't really an issue (doable, have space) but wanted to see what y'all had to say.

[Twigg]

Originally Posted by McPuccio

6x 6v 190AMP AGM for $280 ea for $1600

OR

4x 6v 260AMP Flooded for $184 ea for $800


Pros - AGM over Flood
- No maintenance
- No need for venting

Pros - Flood over AGM
- Cheaper
- Virtually the same amp hours



Hard to see why I would go with AGM tbh but a lot of people we've talked to go with the more expensive option.

We will be living where it gets down to low teens, might leave our bus for a month or two here and there for car trips.

Venting isn't really an issue (doable, have space) but wanted to see what y'all had to say.

Trojan T105-RE for $170-ish

As many as you need following your calculated energy budget.

[McPuccio]

Originally Posted by Twigg

Trojan T105-RE for $170-ish

As many as you need following your calculated energy budget.

I think these are pretty close to the flooded ones we are looking at. Anything particular that puts these over the top of other flooded 6vs?

[Twigg]

Originally Posted by McPuccio

I think these are pretty close to the flooded ones we are looking at. Anything particular that puts these over the top of other flooded 6vs?

Only their reputation for build quality and longevity.

[Kubla]

GC2 6 volt golf cart batteries at SAMs, 84 dollars each

[Tango]

While on the topic of batteries...

I had been looking at some Optimas but discovered they seem to have been having lots of problems lately. Lots of info/discussion online. Just wanted to pass that along.

[Defjr333]

Best price ive seen. NOT include core charge. Sams Club
Doug

[JDOnTheGo]

As noted, you can find relatively inexpensive 6V 220ah-ish flooded batteries - around $90-$100. Even Batteries Plus has a good option (SLIGC115 - Duracell Ultra High Capacity 6V Golf Cart Battery - 230ah are about $100)

Skipping over the commonly available AGM vs. flooded information...

What are YOU like - are you a good owner? Are you going to have a quality battery bank monitoring system and never discharge them below 50% SOC? Are you going to have a quality multi-stage charger? Are you going to water the flooded batteries on a regular schedule? If no to any of these, I would get the cheapest battery possible because you are likely going to destroy them fairly quickly.

On the other hand, if you are going to be a good owner, you will likely get very good life out of a set of batteries. Seven to ten years is not unheard of, so spending extra for quality, name brand batteries is not a bad thing. Of course, even the inexpensive batteries seem to have very good life when taken care of properly.

Available space and access might matter. If you are going to hide these away in tight spaces, the AGM's might be nice. Whether hidden away or accessible, a watering system is SUPER convenient for the flooded batteries - makes watering a very quick and easy task.

[dspizzle]

How do lead acid batteries hold up in extreme temperatures as they will be more likely to be housed underneath the bus w/ the need of venting?

[Twigg]

Originally Posted by dspizzle

How do lead acid batteries hold up in extreme temperatures as they will be more likely to be housed underneath the bus w/ the need of venting?

They hold up well if they are kept charged. If they are allowed to go much under 50% charge, they are at risk when it is extremely cold.

Again, the Trojan (RE) I mentioned will be better than the golf cart batteries. They are designed for energy storage and built tougher than golf cart batteries.

[Defjr333]

I went with the Duracell GC2 for the simple fact of my initial setup is a HUGE test. I could replace all 8 of these and still have only spent the same as 1 set of Trojans. That being said, once I see everything functions as wanted (prob 2 yrs) I will probably upgrade then.

Doug

[Twigg]

Originally Posted by Defjr333

I went with the Duracell GC2 for the simple fact of my initial setup is a HUGE test. I could replace all 8 of these and still have only spent the same as 1 set of Trojans. That being said, once I see everything functions as wanted (prob 2 yrs) I will probably upgrade then.

Doug

So if the batteries are well-cared for, even the cheaper ones should give a few years of decent service. Keep them charged and stick to a discharge level of 50% max. 75% would be better if that works for you mainly because those thinner plates will not resist sulphation as well as the more rugged ones.

There are good reasons why the 6V batteries are so big and heavy

[turf]

i started out with cheap lead acid batterys from walmart (grp 29 marine). they are still running strong at 5 years. the down side of the lead acid is the time it takes to recharge.
once im off shore power, i am lucky to get the lead acid batteries back 70%. its gen time, and i could run the gen 24/7 and still not get the batteries back much past 80%. so why even try?
the agm batteries rechagre, at least to 80% pretty quickly. when these lead acid fail, i will upgrade to agm.
right now i have 4- grp 29 for 400 AH, and i will go to 4- AGM grp 31 for 440ah. in hopes that i will listen to less generator than i do now.

[Defjr333]

Originally Posted by turf

i started out with cheap lead acid batterys from walmart (grp 29 marine). they are still running strong at 5 years. the down side of the lead acid is the time it takes to recharge.
once im off shore power, i am lucky to get the lead acid batteries back 70%. its gen time, and i could run the gen 24/7 and still not get the batteries back much past 80%. so why even try?
the agm batteries rechagre, at least to 80% pretty quickly. when these lead acid fail, i will upgrade to agm.
right now i have 4- grp 29 for 400 AH, and i will go to 4- AGM grp 31 for 440ah. in hopes that i will listen to less generator than i do now.

Sounds like your charger is not set for FLA batteries. AGM take a slightly different voltage than FLAs. My Inverter/ charger has 2 or 3 preprogrammed levels for each as well as other types. With true 3 stage.
Doug

[Ronnie]

has anyone else had trouble with optimas? I have been using them for years now, but lately they do not last. Right now I am not sure what I put in the bus. It is set up for 4 batteries in slide out trays to make watering and cleaning easy.

[turf]

Originally Posted by Defjr333

Sounds like your charger is not set for FLA batteries. AGM take a slightly different voltage than FLAs. My Inverter/ charger has 2 or 3 preprogrammed levels for each as well as other types. With true 3 stage.
Doug

hmmm, i just pulled out the manual and i dont see any setting for the type of battery.
i have an Intellipower 9280 converter/charger. its capable of 80A output but i don't think ive ever seen that.

the problem with smart chargers is they are not generator friendly. they dont charge at the fastest rate possible, like you would want to do off your generator. they sense the battery voltage and slow down the charging to prevent over charging.

so when i come back to a depleted battery bank, i turn on the gen, and i may get 60A charging for a minute or 2, but within 10 minutes, its gone through and sensed voltage and the charge rate is down at 3-5 amps. it takes a while to fully charge a battery bank at 3A.

my solution to my charging problem will be to add solar panels and a charge controller. i see people with solar going into night with 100% charge batteries, and i don't ever see that, even on shore power.

i am sitting here now, listening to my gen charge the batteries. here are 2 shots of my battery meter.

the first show the Battery bank level and the hours need to charge it at that rate.



and this one show the charge current and voltage.



by my meters - i am lucky to run up to 70% and i wear it down to 40%ish

[Twigg]

Originally Posted by turf

hmmm, i just pulled out the manual and i dont see any setting for the type of battery.
i have an Intellipower 9280 converter/charger. its capable of 80A output but i don't think ive ever seen that.

the problem with smart chargers is they are not generator friendly. they dont charge at the fastest rate possible, like you would want to do off your generator. they sense the battery voltage and slow down the charging to prevent over charging.

so when i come back to a depleted battery bank, i turn on the gen, and i may get 60A charging for a minute or 2, but within 10 minutes, its gone through and sensed voltage and the charge rate is down at 3-5 amps. it takes a while to fully charge a battery bank at 3A.

my solution to my charging problem will be to add solar panels and a charge controller. i see people with solar going into night with 100% charge batteries, and i don't ever see that, even on shore power.

I looked at the spec for that unit.

It doesn't appear to have charging profiles required to correctly charge batteries, of any kind

It is restricted to 14.4V for the bulk charge. That is too high (I think) for AGM batteries, and too low for flooded lead/acid. It has a de-sulphation cycle that wouldn't equalize lead/acid, but risks damaging AGM. (you might want to check this, I'm not fully up to date with AGM charging profiles)

It's just the type of compromise so beloved by RV makers, but really doesn't have the facility to maximize the charge in your batteries. The meter will tell you they are at 100% when in reality they may never get above 80% capacity.

There are chargers out there that do a much better job.

[Defjr333]

Sounds like your charger is not capable for different types of batteries. Just checked my inverter/ charger. FLAs Bulk 14.7v, Absorb 14.7v 2 hours, Equalize 15.3v 1-3 hours. AGMs Bulk 14.4v, Absorb 14.4v 1-2 hours, Equalize 14.7v.
Also what size genny you using? Mine is only a 30 amp max output.
Doug

[Twigg]

There are alternative arrangements ...

The one I'm planning uses an AIMS Inveter/Charger as the central component. All sources of power will simply be designed to charge batteries, or provide peak 120V demand for AC or microwave.

So shorepower would feed the inverter, as would the generator and Solar Power when we decide to install it.

That way all the battery charging is done by the charger in the inverter, which has profiles for about nine different battery types.

Crucially, the cycle for flooded lead/acid bulk charges at 14.8V, the level Trojan says is required to fully charge them. Indeed, if temperature monitoring is used it will charge at up to 15.3V. I think the equalization cycle (which runs only very occasionally) is around 18V.

Running the system this way means that the batteries will charge to 100% and sulphation issues are kept to a minimum. Plugged in to shore-power, on site or at home will keep the batteries on float charge, and plugging the genny in will do the same, using as much power from the generator as the charger thinks it needs.

[Defjr333]

Steve, I am using an AIMS inverter/ charger as well. 3000w/ 6000w with 65 amp 3 stage charger. Model PICOGLF30W12V120VR. I do use the temp sensor and remote panel. LOVE IT. As you said, like 8 or 9 pre set voltage curves. With the remote you can also program your own(at your own risk). Got mine for $650 last year on sale. Think they are around $870 now at walmart(online).
Doug