Opinion zone: AGM Deep Cycle Manufacturers

[acadiaforever]

Our dealer has said that they will put a class 24 battery in our Solitude 310GK when we take delivery. I wasn't (am not) very happy about that because the Owner's Manual calls out class 27, but have read here that it is a somewhat common practice.

I'm considering asking for a rebate of the cost of the battery and supplying my own, AGM, battery. I haven't decided whether to go for dual 6V or a 12V yet. I've read many of the posts here about 6 or 12; the consensus seems to be that for serious boondocking we want 2 or 4 6V batteries.

In trying to read about AGM manufacturers, there seems to be very little on the net in the way of independently comparing / reviewing their products. Every one seems to be the best!

So, if you're willing, which are the manufacturers to focus on? Which do you have, and why did you choose it?

If I can hijack my own thread, another point is battery mounting. I've read here that the "stock" battery box can handle a 27. What changes have people had to make to secure 2 6V GC batteries up front?

Thanks for pointers and opinions.
-Al

 

[BabyBober]

FYI, I think GD specs a group 27. Don't let the dealer cheat you...

 

[Devinh2]

I went with 4 Full River 250AH AGM batteries to support my solar system. They have a 7 year warranty and are maintenance free.

 

[orbiker]

I took in 2 Optimis batteries that were almost new (came out of the pickup camper) into the dealer. I had them install them and they could keep their cheep battery they were going to put in it.

 

[D2Reid]

What changes have people had to make to secure 2 6V GC batteries up front?
Thanks for pointers and opinions.
-Al

I am no solar/boondocking/battery expert, so for what's it's worth.

The battery box that was installed in my new Momentum 376TH had a type 24 battery in it. I killed it the first time we boondocked. That lead me to upgrading. I was all excited about 2 type 27 AGM batteries until the battery girl in SLC questioned my thinking. She threw a lot of numbers at me, most of which I barely understand, but essentially what she said was I could get the same performance out of 2 6 volt batteries that I could out of 2 AGM batteries, oh yeah, they are about $300 less expensive.

So I went with 2 6v US Batteries 2200 series. I bought another battery box for around $20. I used the venting system already installed with some minor modifications to ensure hydrogen gas venting. It sill needs some work. I placed it in the original battery position in the front bay next to the generator. It would take some work to get 2 more 6v installed there, I would have to move a lot of electrical hookups to do this. I do plan on upgrading the battery box, right now mine is held together with duct tape, acceptable in the temporary, not permanent.

Years ago I tried to get a handle on battery quality. After a few weeks of investigation and reading lots of reviews I couldn't get a definitive answer. I had an issue with a boat battery and needed a battery pronto, so I bought a battery from Auto Zone. That stupid battery out lasted 2 others that I paid more money for. I don't know why, but I now buy batteries from Auto Zone, are they better, probably not, but I think they are as good as most others, and the warranty thing is based on my phone number so I don't have to worry about losing the receipt.

I would definitely talk to the dealer about upgrading the battery. Me, I would settle for getting a battery credit and then pay them the difference to properly install mo betta batteries.

 

[DNBrown293res]

Another great resource for info a great batteries is Interstate. Knowledgeable and wonderful service.


Sent from my iPhone using Tapatalk

 

[ShooTingSTar]

We went with 4 AGM 6 volt batteries and 3 160 watt solar panels on the roof with controller. So far so good. NOT CHEAP!

 

[Dopperud]

You may want to take a look at Li-ion batteries. They are more expensive up front, but over the life of the batteries, there is little difference. The biggest advantages are usable power, weight, and charging speed. This is the best deal I've found so far and I expect prices to continue to drop as availability and popularity increase.

https://battlebornbatteries.com

 

[TucsonJim]

You may want to take a look at Li-ion batteries. They are more expensive up front, but over the life of the batteries, there is little difference. The biggest advantages are usable power, weight, and charging speed. This is the best deal I've found so far and I expect prices to continue to drop as availability and popularity increase.

https://battlebornbatteries.com

Yikes! $899 for a 100 amp hour battery. I'll wait until the prices drop a whole bunch.

Jim

 

[Dopperud]

Yikes! $899 for a 100 amp hour battery. I'll wait until the prices drop a whole bunch.

Jim

Up front no question it's more expensive. But that's not the whole story. An AGM battery can only be taken down to 50% without damage where a LI-ion can routinely be taken down 80% so to get an equivalent amount of usable power you need to get a 160 Ah battery, which is about $400. An AGM battery will last 500 cycles, but lets even push it out to 1000. A Li-ion battery will last 3000+ cycles and even then will retain 80% capacity. so if you replace your AGM battery twice, the cost it virtually the same.

Now the other benefits:

Li-ion 29# vs 95# for the AGM
No drop off in power until drained, no dimming lights, etc
Very fast charging - full charge rate till full

If you are getting something for a short term, low demand, then AGM is the winner. If long term, high demand investment, the Li-ion deserves a look.

 

[el Rojo]

I went with 4 Full River 250AH AGM batteries to support my solar system. They have a 7 year warranty and are maintenance free. View attachment 10231

X2. We'e had 4 of these for 2 1/2 years with no problems. Lifeline (brand) is considered to be the Michelen of the battery where Full River is the Goodyear. I got mine in Quartzsite AZ and they had pallets of Full River but would have to order Lifeline.

Li-ion is the new thing going for RV's. It's the battery type we have in cell phones and the Radio Control airplane world has gone to them.

Red

 

[el Rojo]

I went with 4 Full River 250AH AGM batteries to support my solar system. They have a 7 year warranty and are maintenance free. View attachment 10231

X2. We'e have had 4 of these for 2 1/2 years with no problems. Lifeline (brand) is considered to be the Michelen of the battery where Full River is the Goodyear. I got mine in Quartzsite AZ and they had pallets of Full River but would have to order Lifeline.

Li-ion is the new thing going for RV's. It's the battery type we have in cell phones and the Radio Control airplane world has gone to them.

Red

 

[DaveMatthewsBand]

Up front no question it's more expensive. But that's not the whole story. An AGM battery can only be taken down to 50% without damage where a LI-ion can routinely be taken down 80% so to get an equivalent amount of usable power you need to get a 160 Ah battery, which is about $400. An AGM battery will last 500 cycles, but lets even push it out to 1000. A Li-ion battery will last 3000+ cycles and even then will retain 80% capacity. so if you replace your AGM battery twice, the cost it virtually the same.

Now the other benefits:

Li-ion 29# vs 95# for the AGM
No drop off in power until drained, no dimming lights, etc
Very fast charging - full charge rate till full

If you are getting something for a short term, low demand, then AGM is the winner. If long term, high demand investment, the Li-ion deserves a look.

^ what he said.
People always balk at the upfront price but you get what you pay for rings true big time here.
Then again I see people buying the least expensive tires they can find, which always makes me cringe.

 

[sande005]

Late to the party on this topic, but you may want to look at this thread from a fishing forum. Their needs are the same - longest lasting power at the cheapest cost. The first post compared various Group 31 AGM batteries, with many chiming in after that.
http://www.walleyecentral.com/forums/showthread.php?t=528793&highlight=agm+battery

 

[sande005]

Up front no question it's more expensive. But that's not the whole story. An AGM battery can only be taken down to 50% without damage where a LI-ion can routinely be taken down 80% so to get an equivalent amount of usable power you need to get a 160 Ah battery, which is about $400. An AGM battery will last 500 cycles, but lets even push it out to 1000. A Li-ion battery will last 3000+ cycles and even then will retain 80% capacity. so if you replace your AGM battery twice, the cost it virtually the same.

Now the other benefits:

Li-ion 29# vs 95# for the AGM
No drop off in power until drained, no dimming lights, etc
Very fast charging - full charge rate till full

If you are getting something for a short term, low demand, then AGM is the winner. If long term, high demand investment, the Li-ion deserves a look.

Most, but not all, of the Lithium batteries sold for this kind of application are Lithium Iron (Li-Fe) rather than Lithium Ion or Lithium Poly. Li-Fe's are FAR safer than the most of the ones you hear about exploding, catching fire, etc. It is critical when purchasing to make sure. But even Li-Fe's can be made to catch fire if abused.
All lithiums need a specialized charger to charge them, and each kind needs a differently configured charger. You cannot just use any old charger you happen to have around. It is critical that it is built with proper detection and safety circuitry to prevent any amount of overcharging (see above about explosive fires!). Either the charger or the batteries must also be equipped to detect variations in voltages between cells, and compensate the charge accordingly (balancing). Not having that will greatly reduce their life. While they will not self discharge, storage at full charge greatly reduces their lifespan, so if not used for even moderately short periods (a few weeks or more) they should be discharged to a specific partial state ("storage charge"). Which means charging up again before using. There isn't a good way to trickle charge them, or keep them on a maintainer long term. Charging them when the temp is at freezing or below causes permanent damage and loss of capacity AND charging when below freezing can even cause the above mentioned fires/explosions. But, you can use them when it is cold - you just have to warm them up before recharging them. Oh, and running them down to zero just once kills them completely.
So the weight and power advantages are fantastic. The cost and need for much, much more attentive babysitting is not so great.

 

[J&G garage]

That is the best "in a nutshell" explanation of the care and feeding of lithium batteries for RVs I've seen. There is a lot more to the installation of these batteries than some would have you believe. I have a bunch of Lipo (lithium-polymer) batteries I use for radio controlled model helicopters. Owning these things is as much work as having a litter of puppies. I've invested hundreds of $$ in a charger, power supply, parallel cables and circuit boards just to charge them. I charge them inside a modified steel ammo can on a non flammable surface (I should be charging them outside). When not used for a long period they get stored in a refrigerator in the garage and then warmed before charging. If they are charged and not going to be used for a few days they are put on a special charger that discharges them to a storage voltage. I keep a log of charge cycles, discharge state and internal resistance of each cell. I do all this for safety sake and to get the most cycles out of these VERY expensive batteries. Granted Lipo batteries are a little more finicky than Life batteries but the concept is the same. I don't think it's fair to just compare amp/hour/dollar when comparing Lithium batteries with AGM or flooded cell batteries as there are additional expenses and actions required to use these lithium batteries safely and efficiently.

 

[TheSpareTire]

All lithiums need a specialized charger to charge them, and each kind needs a differently configured charger. You cannot just use any old charger you happen to have around.

Battle Born battery’s address this topic claiming otherwise. Using a multistage charger is compatible with their batteries: https://battlebornbatteries.com/charging-battleborn-lifepo4-batteries/

In talking with these guys they made me understand that any charger is compatible. I also talked with a Chinese manufacture who also echoed in their testing that multistage chargers may not provide a optimal charging rate but will work.

Charging them when the temp is at freezing or below causes permanent damage and loss of capacity AND charging when below freezing can even cause the above mentioned fires/explosions.
But, you can use them when it is cold - you just have to warm them up before recharging them.

Many BMS systems today have a tempature sensor that will prevent the battery from charging if it is too cold. It’s not necessarily a task you need to determine. A good BMS will allow a low voltage charge to warm the core before it starts a full charge.

Normally drawing some power off the battery when it’s cold will warm the cells enough to pull a regular charge.

Oh, and running them down to zero just once kills them completely.

I am not aware of a BMS that exists that will allow you to actually run the battery below (or above) a safe voltage.

 

[TheSpareTire]

An AGM battery can only be taken down to 50% without damage where a LI-ion can routinely be taken down 80% so to get an equivalent amount of usable power you need to get a 160 Ah battery, which is about $400.

Many (not all) LIFEPO4 coming out now can perform a 100% DOD (Depth of Discharge) for thousands and thousands of cycles. Some manufactures build in extra cells for reserved capacity that is used in conjunction with the BMS to prevent actual full discharge.

 

[sande005]

My comments were generic to the lithium battery subject. Yes, Battle Born (and I assume others) are working to get them to be as plug-and-play as possible. Things like using the already existing chargers as power supplies for the BMS hidden inside their cases, temperature monitoring, etc. Same kind of thing that is already done for laptops, drills, phones, etc. but scaling up for more capacity. Hence another reason for the cost difference between lithium and lead-acid. Just pointing out that the technology requires much more awareness about its use, and potential limitations, and in itself it is very different than what has been used before. Because of the greatly increased potential for serious consequences, the potential user must get into the pretty technical details and make sure that however they implement it, it is done correctly - by them, or by the vendor they choose to buy from. Hoverboards are a prime example of what happens when it is just accepted that what the vendor sold is appropriate.

 

[Dopperud]

I am glad that different people are chiming in on this topic. I am a firm believer that this change in energy storage is going to be one of the biggest technological breakthroughs in the coming years. We are now generating a great deal of energy from alternative sources other that fuels, the biggest roadblock has been storage. Lead acid has been around for a century and has been taken about as far as it can go. The LiFePO4 technology is the future that is available now. This technology will continue to improve and become less expensive as economy of scale improves.

Have there been problems, yes. But comparing them to HoverBoards, is unfair as would be saying you have to worry about outgassing of lead acid batteries when using an AGM battery.