Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: erniee on August 17, 2023, 05:14:31 pm

Title: 8D AGM
Post by: erniee on August 17, 2023, 05:14:31 pm
I have these- 3- in our coach as house batteries. They are 7 years old. Since we never dry camp and go from pole to pole and run the generator, do I really need 8d or can I go smaller?
8 ds are scarce
I wanted to stay with AGMs as that's what the charger is programmed for
Title: Re: 8D AGM
Post by: wolfe10 on August 17, 2023, 05:19:55 pm
Ernie,

Yes, you certainly can go with less amp-hr battery capacity.

Depending on spacing in your house battery bank compartment, 2 8 D's OR perhaps 4 6VDC golf cart batteries (series parallel).  Measure to see if the golf carts will fit.

For maintenance-free, suggest AGM's.
Title: Re: 8D AGM
Post by: turbojack on August 17, 2023, 05:28:24 pm
Just because they are 7 years old you don't have to replace them unless one or more have given up.

In my old U295 one of my 3 8D's shorted out. I just removed it and just went with 2.
Title: Re: 8D AGM
Post by: oldguy on August 17, 2023, 05:36:33 pm
If it aint broke why fix it. When I bought my coach the previous owner said the batteries where
ten years old and then he said 14 years old but they were old. I wanted silicone batteries so I
put them in and gave my son the old AGM batteries and he is still using them and that was 4
years ago.
Title: Re: 8D AGM
Post by: erniee on August 17, 2023, 05:39:17 pm
I load tested them and they are marginal
Title: Re: 8D AGM
Post by: craneman on August 17, 2023, 05:51:49 pm
Many members are using these and getting a better price than posted when buying. Even if you don't dry camp you might have an engine battery problem and want to be able to use your boost. Also if you use the inverter you need capacity.

https://www.oreillyauto.com/detail/c/fleet-heavy-duty/marine---boat/batteries---marine---deep-cycle/deep-cycle---marine-batteries/6bf1f04ea895/super-start-fleet-heavy-duty-battery-group-size-8d/ssbl/agm8d
Title: Re: 8D AGM
Post by: erniee on August 17, 2023, 06:25:34 pm
" if it ain't broke"  anyone have a timeline when a battery will crap out? I don't.
Title: Re: 8D AGM
Post by: Dub on August 17, 2023, 07:08:08 pm
There is no "time line" they are good until they're not. I will leave my AGM 8d's in the compartment until I sense a problem.
Title: Re: 8D AGM
Post by: bbeane on August 17, 2023, 07:57:08 pm
Many members are using these and getting a better price than posted when buying. Even if you don't dry camp you might have an engine battery problem and want to be able to use your boost. Also if you use the inverter you need capacity.

https://www.oreillyauto.com/detail/c/fleet-heavy-duty/marine---boat/batteries---marine---deep-cycle/deep-cycle---marine-batteries/6bf1f04ea895/super-start-fleet-heavy-duty-battery-group-size-8d/ssbl/agm8d
Just relaced my 7 year old Oreilly AGMs 3 of the same.  If you decide to go that way be sure and check the voltage on before you leave the store.
Title: Re: 8D AGM
Post by: Dub on August 17, 2023, 08:22:45 pm
I've had no complaints about my Orielly's 8d's. If a battery showed low voltage new at the store and had a new mfg date would you have them charge it or choose a different one?
Title: Re: 8D AGM
Post by: Dub on August 17, 2023, 08:35:01 pm
Or have them charge it then load test it? I've never had one checked new at the store but seems to not be a bad idea. Mine only come with 1 year warranty.
Title: Re: 8D AGM
Post by: Moby on August 17, 2023, 10:13:52 pm
Just put a set of 3 8D's in Alice.
Less than the cost of golf cart batteries for a negligible difference in capacity.
Don't dry camp much so the lower capacity ain't a big deal.
 If you go the golf cart route, don't forget to include the cost of the required extra cables.
Title: Re: 8D AGM
Post by: Dakota Slim on August 17, 2023, 10:20:13 pm
My bank of six 6v golf cart house batteries lasted 8 years in mostly off grid use and last summer I had to do something. I've been plugged in since the virus hit and have no plans to dry camp so I opted to go with the biggest Walmart AGM they had and it has worked like a champ for the last 14 months.
EverStart Platinum AGM Battery, Group Size H8 (12 Volt/900 CCA)
$169.84/EA
I don't have to worry about watering lead acid GC batteries and this one has a 4 year free replacement guarantee.
Title: Re: 8D AGM
Post by: Pierce & Gaylie Stewart on August 17, 2023, 10:35:35 pm
We purchased our 6 AGMs in 2008 and they are still going strong. We have kept the voltage about 13.2 when at home. They only total about 400ah. I don't trust Li-Ion not to fail in a big way.

Pierce
Title: Re: 8D AGM
Post by: bbeane on August 18, 2023, 12:27:32 am
Or have them charge it then load test it? I've never had one checked new at the store but seems to not be a bad idea. Mine only come with 1 year warranty.
I ordered 3 8D AGMs 2 where 12.8 volts, one was 11.6 they ordered me another one for next day.
Title: Re: 8D AGM
Post by: Lon and Cheryl on August 18, 2023, 04:26:04 am
You could see if (2) Lifeline AGM, L16, 6v battery's would fit. More capacity than (3) 8d and less room needed, but more height required. Very reliable build quality and the only AGM that I know of. that can be equalized charged.
Title: Re: 8D AGM
Post by: Pierce & Gaylie Stewart on August 18, 2023, 10:21:06 am
You could see if (2) Lifeline AGM, L16, 6v battery's would fit. More capacity than (3) 8d and less room needed, but more height required. Very reliable build quality and the only AGM that I know of. that can be equalized charged.
Lon, I noticed on our Genesis XE70x EnerSys Genesis XE70X 0771-6003 Battery 68Ah Metal Jacket | OSI Batteries (https://www.osibatteries.com/enersys-genesis-xe70x-0771-6003-battery-68ah-metal-jacket)
batteries that equalizing was not possible but when I installed our Progressive Dynamics converter/charger, I called the battery manufacturer to ask about it. They said that the PD unit only uses the equalizing mode for a short time and would not harm the six batteries. They are 15 years old now and going strong.

The XE70x batteries were from a bankrupt solar company and were $35/ea, not $526.

Pierce
Title: Re: 8D AGM
Post by: WagonWheels on August 18, 2023, 11:16:58 am
If possible, load test the new batteries at the store where you purchase them.  A couple years ago I had new engine batteries (3) installed at Cummins, El Paso.  They had the new batteries delivered from a local distributor.  First thing Cummins did was load test when the batteries were delivered.  Sure enough, one was bad.  Technician said load testing of new batteries was SOP.  We have Lifeline 8D AGM house batteries.  Lifeline instructions recommends their AGM batteries be equalized periodically. 
Title: Re: 8D AGM
Post by: Dakota Slim on August 18, 2023, 10:01:31 pm
My bank of six 6v golf cart house batteries lasted 8 years in mostly off grid use and last summer I had to do something. I've been plugged in since the virus hit and have no plans to dry camp so I opted to go with the biggest Walmart AGM they had and it has worked like a champ for the last 14 months.
EverStart Platinum AGM Battery, Group Size H8 (12 Volt/900 CCA)
$169.84/EA
I don't have to worry about watering lead acid GC batteries and this one has a 4 year free replacement guarantee.
I should add that my solar panels are overkill for this house battery and the amount of house battery power I use these days. The only time I draw down on the house battery is after dark or early AM and the house battery is full within minutes of the sun coming up. I have a trickle charger powered by the house battery that keeps my 8D starting battery fully charged.
Title: Re: 8D AGM
Post by: Protech Racing on August 19, 2023, 10:27:17 am
Rural king has cheap 8 d batteries and the best warranty. They work fine for non deepcycle use
Title: Re: 8D AGM
Post by: Old Toolmaker on August 21, 2023, 08:19:02 am
Rural king has cheap 8 d batteries and the best warranty. They work fine for non deepcycle use
To the best of my knowledge the only solid-plate deep-cycle batteries are manufactured by Trojan, even so you need to read the description carefully.  All the other lead acid batteries advertised as "deep cycle" should be considered deep(er) cycle.
Title: Re: 8D AGM
Post by: propman on August 21, 2023, 06:08:23 pm
8D = to heavy not efficient. For my money, I replaced 3 8Ds with one LiTime 12V 300Ah Lithium (https://www.amazon.com/gp/product/B08K7HZ6KZ/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&th=1)
Title: Re: 8D AGM
Post by: JCinPA on August 22, 2023, 12:12:37 am
I installed three Renogy 200ah gel cell batteries this spring and they seem to be doing fine. They run about $400 a piece and they have 200ah AGMs around the same price or a little cheaper. They delivered them to my door for that price. The only thing I had to do extra is locate screw in terminals to convert them from bolt on terminals, I believe that was an Amazon purchase, not very expensive. Renogy is available on Amazon and Home Depot.
Title: Re: 8D AGM
Post by: TGordon on August 22, 2023, 12:58:06 am
8D = to heavy not efficient. For my money, I replaced 3 8Ds with one LiTime 12V 300Ah Lithium (https://www.amazon.com/gp/product/B08K7HZ6KZ/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&th=1)
Ditto, I am doing the same, I have the battries, I need to install them.
Title: Re: 8D AGM
Post by: P. Wyatt Sabourin on August 22, 2023, 03:53:01 pm
Buyer beware!! Here is an article explaining the misleading information about "deep cycle batteries" in USA and Canada, such that few batteries labeled with "deep cycle" are really deep cycle batteries.
What is a Deep Cycle Battery? - Marine How To (https://marinehowto.com/what-is-a-deep-cycle-battery/)
A battery labeled with "dual purpose", "marine deep cycle", or "start deep cycle" are light duty for deep cycle because they will only provide circa 250-300 cycles down to  75% charged. This will work if you only occasionally boon dock.
A GC2 battery (wet or AGM) or a true deep cycle AGM battery will provide circa 900-1200 cycles down to  75% charged.
A GC2 GEL battery or a true deep cycle GEL battery will provide circa 2000-2500 cycles down to  75% charged. This is why Foretravel installed GEL batteries in our coaches when they were new. My personal experience includes 1200 cycles from AGM 8D batteries and 2400-2800 cycles from GEL 8D batteries.

EQUALIZING:
Any wet, AGM, or GEL battery can be equalized even if manufacturer says it cannot.
An equalizing charge is nothing more than a deliberate 15+volt overcharge to re-dissolve sulfate compounds. The problem with equalizing a sealed battery has to do with how quickly the gasses produced will recombine back to water. Producing gas faster than the recombining process will cause the battery to become pressurized and at about 5 psi, the excess pressure will be released into the air which means battery capacity is lost forever. If you see a sealed battery with bulging sides or top, it has been charge too rapidly while hot.
I do not equalize my batteries, I desulfate them continuously.
Title: Re: 8D AGM
Post by: TGordon on August 22, 2023, 08:16:17 pm
Buyer beware!! Here is an article explaining the misleading information about "deep cycle batteries" in USA and Canada, such that few batteries labeled with "deep cycle" are really deep cycle batteries.
What is a Deep Cycle Battery? - Marine How To (https://marinehowto.com/what-is-a-deep-cycle-battery/)
A battery labeled with "dual purpose", "marine deep cycle", or "start deep cycle" are light duty for deep cycle because they will only provide circa 250-300 cycles down to  75% charged. This will work if you only occasionally boon dock.
A GC2 battery (wet or AGM) or a true deep cycle AGM battery will provide circa 900-1200 cycles down to  75% charged.
A GC2 GEL battery or a true deep cycle GEL battery will provide circa 2000-2500 cycles down to  75% charged. This is why Foretravel installed GEL batteries in our coaches when they were new. My personal experience includes 1200 cycles from AGM 8D batteries and 2400-2800 cycles from GEL 8D batteries.

EQUALIZING:
Any wet, AGM, or GEL battery can be equalized even if manufacturer says it cannot.
An equalizing charge is nothing more than a deliberate 15+volt overcharge to re-dissolve sulfate compounds. The problem with equalizing a sealed battery has to do with how quickly the gasses produced will recombine back to water. Producing gas faster than the recombining process will cause the battery to become pressurized and at about 5 psi, the excess pressure will be released into the air which means battery capacity is lost forever. If you see a sealed battery with bulging sides or top, it has been charge too rapidly while hot.
I do not equalize my batteries, I desulfate them continuously.

I think bulging battries are the cause of batteries going concave, when they cool; not enough electrolyte after overcharging.
Title: Re: 8D AGM
Post by: dans96u295ft on August 27, 2023, 09:36:31 am
I bought 4 AGM's and am very happy and they are lighter and I dry camp up to 5 days without solar. I just run the genny daily to charge