8 AGM house batteries!

[Roadtrek69]

I own a class B 2015 Roadtrek CS Adventurous with an Etrek option. This option equips the coach with 8 (yea, eight!) AGM house batteries. The owner's manual suggests these batteries should last 6-10+years. I am on the low end of that time frame. The batteries seem to be having difficulty holding a charge even with the battery switch turned off and a 600watt solar panel attempting to maintain the charge. I Assume the batteries need replacing. The battery supplier needs to know what the battery number is but does not have a source for that information. The owners manual does not provide that info, either. Can anybody inform me what battery number is being used for this set up?:thanx:
Jim

 

[rowiebowie]

I own a class B 2015 Roadtrek CS Adventurous with an Etrek option. This option equips the coach with 8 (yea, eight!) AGM house batteries. The owner's manual suggests these batteries should last 6-10+years. I am on the low end of that time frame. The batteries seem to be having difficulty holding a charge even with the battery switch turned off and a 600watt solar panel attempting to maintain the charge. I Assume the batteries need replacing. The battery supplier needs to know what the battery number is but does not have a source for that information. The owners manual does not provide that info, either. Can anybody inform me what battery number is being used for this set up?:thanx:
Jim

Welcome to the forum Jim!

I don't have the information you seek, but someone on this forum probably does. Have your 5 years of Etrek ownership been relatively trouble-free? If so, you are ahead of the game.

 

[gregmchugh]

I own a class B 2015 Roadtrek CS Adventurous with an Etrek option. This option equips the coach with 8 (yea, eight!) AGM house batteries. The owner's manual suggests these batteries should last 6-10+years. I am on the low end of that time frame. The batteries seem to be having difficulty holding a charge even with the battery switch turned off and a 600watt solar panel attempting to maintain the charge. I Assume the batteries need replacing. The battery supplier needs to know what the battery number is but does not have a source for that information. The owners manual does not provide that info, either. Can anybody inform me what battery number is being used for this set up?:thanx:
Jim

Since your batteries have lasted for 5 years it is likely that you already have a battery equalizer in your system. If you don’t then you should get one installed before replacing the batteries. Any golf cart sized 6 volt AGM batteries should be okay to use, Lifeline is one of the higher quality brands. Look at the ones under the hood to see what brand and model number were used by RT.

 

[Rockwood27]

Instead of replacing all 8 batteries, you should have each one individually tested. It's possible that 1 or two batteries are bad and dragging down the whole system. If it's found to be true then you could eliminate the pair (assuming they're 6V batteries) and run on 6 batteries.

 

[wny-pat]

Measure the battery! https://www.batteryequivalents.com/bci-battery-group-size-chart.html

 

[gregmchugh]

Instead of replacing all 8 batteries, you should have each one individually tested. It's possible that 1 or two batteries are bad and dragging down the whole system. If it's found to be true then you could eliminate the pair (assuming they're 6V batteries) and run on 6 batteries.

The 8 batteries are wired for 24 volts, cannot run with 6 batteries. Best to replace all to have a matched set.

 

[booster]

Instead of replacing all 8 batteries, you should have each one individually tested. It's possible that 1 or two batteries are bad and dragging down the whole system. If it's found to be true then you could eliminate the pair (assuming they're 6V batteries) and run on 6 batteries.

This should be a 24/12v wired system with two strings of 4 batteries each with a 12v center tap so would not really be able to use just 6 batteries unless he went to 6 eight volt GC batteries, which we have discussed here in past discussions.

 

[Roadtrek69]

Thanks

Welcome to the forum Jim!

I don't have the information you seek, but someone on this forum probably does. Have your 5 years of Etrek ownership been relatively trouble-free? If so, you are ahead of the game.

Thanks for your welcome and response. I purchased this RV used almost two years ago(Dec.'18). Really like the vehicle but it has not been trouble free. Had to have the invertor rewired and am now having battery issues. Hopefully, new batteries address the problem and we can have some trouble-free travel!
Thanks again.

 

[Roadtrek69]

Thanks for your reply and advice. Considering the batteries are almost 6 years old and they provide all the electrical power when not hooked up to shore power or have the engine running to engage the belt driven generator. I would prefer to have all the power available and designed for. Plus, apparently, all eight are required in order to provide the voltage everything is designed to operate on.
Thanks again for your input and advice. Jim

 

[Roadtrek69]

Thanks for your response and information. Good education! Was unaware of the two banks of four. Thanks again. Jim

 

[Roadtrek69]

Thankyou for your response and advice. I had not considered the cab batteries could be the same as the house batteries. Will need to verify. Thanks again. Jim

 

[Roadtrek69]

Thank you for your response to my problem. I agree the batteries should be individually inspected. The problem is they are in a battery box under the vehicle and are not easily accessible. In addition, once I go through the expense of gaining access to all the batteries would I really want to install one or two new batteries and pair them up with 6 or 7 old batteries? It will be EXPENSIVE!!!
Thanks again for your time and advice. Jim

 

[Dougm38]

Try Sunshine State RV in Gainsville, Fl. They are great.

 

[ProseMan]

I have the exact same setup. Same year, same model. You DEFINITELY need to have the battery equalizers added to the system. This is likely the reason for your problem and may fix it. Btw, how do you know they aren't holding a charge? Also, if you have a single solar panel on the roof, it's 300 watts, not 600.

 

[JohnnyCLE]

Thankyou for your response and advice. I had not considered the cab batteries could be the same as the house batteries. Will need to verify. Thanks again. Jim

There are over 17 pages of content on this forum if you do a search on E-Trek. A real education if you want to sort through them. The MB chassis battery is located underneath the driver's floorboard. The two batteries in the engine compartment are part of the 8 AGM house set along with the six in back.

Since you purchased the unit used there is a possibility the prior owner may have already done some battery swapping re brand name, etc. even if the sizes are the same. An experienced RV tech should recognize the size and model number by sight. If you are hiring someone to do this work and they can't do this be cautioned that the 8 AGM E-Trek is a unique animal and the more experience the better.

 

[Roadtrek69]

Try Sunshine State RV in Gainsville, Fl. They are great.

I have considered them. Good to hear from a satisfied customer. Have been putting off making arrangements due to their being about 1 1/2 hours away. I guess it is time for a road trip! Thanks for your referral.

 

[Roadtrek69]

I appreciate your advice. I am having a little difficulty finding a qualified service facility close to me that is familiar with the Etrek option. Will need to keep shaking the bushes. Thanks again.

 

[Dougm38]

You are welcome

 

[hdevera]

I own a 2015 CS etrek also. I was one of the original owners who installed the battery balance which RT copied. My suggestion (if you wish to stay with AGMs) is to install the balancer and fully charge at least for 24 hrs. and check the voltages at night with no load and no current going in. If the voltages of each battery have equalized (within 0.05v) then you likely will be ok without changing all 8 batteries. I over nite charged my batteries weekly to keep them balanced. If there is a large voltage difference, you should change all batteries at the same time. US battery makes a 225Ah battery 6v battery that fits fine. Not hard to replace. If you decide to go with lithium (which I just did), I suggest you go with Battleborn 50Ah 24v batteries hooked in parallel. You will need 4 of these to be equal to your current useable watt hrs. I went with six and I love it. I also upgraded the alternator and regulator and added a Victron monitor. I also upgraded the wiring to the batteries from the alternator. RT did a terrible job with their electrical system in the etrek. Changing to lithium is expensive but if you plan to keep your vehicle and you need to get new batteries, think twice about staying with AGMs.

 

[JohnnyCLE]

If you decide to go with lithium (which I just did), I suggest you go with Battleborn 50Ah 24v batteries hooked in parallel. You will need 4 of these to be equal to your current useable watt hrs. I went with six and I love it. I also upgraded the alternator and regulator and added a Victron monitor. I also upgraded the wiring to the batteries from the alternator. RT did a terrible job with their electrical system in the etrek. Changing to lithium is expensive but if you plan to keep your vehicle and you need to get new batteries, think twice about staying with AGMs.

Interesting upgrade. Did you repurpose the balancer in this or install a DC-DC converter for 12v support? Were the two AGMs in the engine compartment eliminated? Did you need to upgrade the solar controller as well? Assuming the 6 new batteries went into the undercarriage rack, is the environmental protection to "stay out of cold weather" or did you add some protection?