Converting to 6v batteries

[marter]

Hello,

I currently have a pair of 2 year old Interstate SRM-24s in our 2008 International 19'. I'd like to get more AHs without a ton of money, so I'm planning on switching to 6v GC2s (Costco or Sams) and have a couple questions. First,

• I realize they won't fit without modifying the battery box, and have a battery box extender on the way from Vinnie's Airstream.
• I've previously changed out the charger/controller to a PD 4655.
• We have the factory 50w solar with the Atkinson charge controller; we may add a 100w portable at some point.

Is this as simple as wiring the two 6-volt batteries in series (one pos to the other neg) and connecting all loads (trailer, inverter, jack and brake controller) to the single 6v pos terminal and same with negative cables?

I'm also considering adding the Victron BMV-712 with BT, but I'm not sure I see enough value. I don't know how the temp sensor works; I assume it has to be connected to a compatible charger? I don't see how it could it be functional with my PD4655?

In view of the potential for a portable solar panel in the future, is there anything else I should consider now or in the future?

Thanks in advance,
Mike

[rmkrum]

Yup, wire them in series exactly as you described.
Consider a battery watering system to make maintenance much easier, and consider adding a mechanical shut-off switch to kill all parasitic loads when in long term storage.
Plenty of threads on the subject.

[marter]

Originally Posted by rmkrum

Yup, wire them in series exactly as you described.
Consider a battery watering system to make maintenance much easier, and consider adding a mechanical shut-off switch to kill all parasitic loads when in long term storage.
Plenty of threads on the subject.

Thanks. I hadn't considered a watering system but that looks like a great idea. So is there a reservoir or is it manual? I'll start researching.

I've been reading the threads on the disconnect switch but have been disconnecting the neg cables during storage. Someday I'll do one when I replace the battery cables along with some wire management tasks i've been putting off. I want to take the dinette seat out when I do that and am not looking forward to that.

Any comment on the BMV temp probe working with my charger? Need to understand how that works.

Thanks again,
Mike

[rmkrum]

The battery watering system I have has a filler bulb and a short spigot that you fill with distilled water, plug on to a connector that leads to the float valves in the cells. Then you squeeze gently until you feel resistance. That means the cells are now filled. Then you disconnect. The same filler can be used on regular batteries manually. No reservoir in this system.

[68 Overlander]

By the time you invest in a watering system, aren't you near the cost of some entry level AGMs that don't need one. You still have to monitor a watering system like sprinklers in a yard.

[rmkrum]

Yeah, maybe the first time. I can buy a lot of GC-2 golf cart batteries for the cost of AGMs, and can get them from Sam’s or Costco. As long as I use GC-2 batteries, I can transfer the watering system easily.

[HiHoAgRV]

Originally Posted by rmkrum

Yeah, maybe the first time. I can buy a lot of GC-2 golf cart batteries for the cost of AGMs, and can get them from Sam’s or Costco. As long as I use GC-2 batteries, I can transfer the watering system easily.

X2!

I'm pretty good at killing batteries. Headed to Sams tomorrow to replace my 5 year old $85 set.

[68 Overlander]

Originally Posted by rmkrum

Yeah, maybe the first time. I can buy a lot of GC-2 golf cart batteries for the cost of AGMs, and can get them from Sam’s or Costco. As long as I use GC-2 batteries, I can transfer the watering system easily.

No question they are half the cost and last half a long. 5 years is respectable on flooded for somebody that takes care of them. 11th year on Lifelines 1 month shy of 12 year but 20 percent faster charging and only peek on them once a year to make sure they haven't been stolen Certainly no argument, just different perspective on technology. Lithium folks are spending $950+ on 100 AH batteries like they are going out of style for their benefits so the only correct answer is what's right for you

[marter]

I got two GC2 Duracells at Sam's on a 1-day sale yesterday for $74 each plus tax. I had 2 cores to trade. Looks like a Flow-Rite watering system from Amazon will run another $75. Probably not a bad idea.

[Zil]

Sam's Duracell EGC2's are much better than anything from Cosco. Batteries plus Bulbs also have Duracell.

[Mangin]

Costco 6V are a great deal. I switched 4 years ago. The caps come off easily. I only have to top up the water twice a year. For the box, I bought a 1x1" piece of pressure treated board, painted it black then screwed it to the top the original box. Reattach the lid to the now taller box and you are all set.

[frank nordyk]

Originally Posted by marter

Hello,

I currently have a pair of 2 year old Interstate SRM-24s in our 2008 International 19'. I'd like to get more AHs without a ton of money, so I'm planning on switching to 6v GC2s (Costco or Sams) and have a couple questions. First,

• I realize they won't fit without modifying the battery box, and have a battery box extender on the way from Vinnie's Airstream.
• I've previously changed out the charger/controller to a PD 4655.
• We have the factory 50w solar with the Atkinson charge controller; we may add a 100w portable at some point.

Is this as simple as wiring the two 6-volt batteries in series (one pos to the other neg) and connecting all loads (trailer, inverter, jack and brake controller) to the single 6v pos terminal and same with negative cables?

I'm also considering adding the Victron BMV-712 with BT, but I'm not sure I see enough value. I don't know how the temp sensor works; I assume it has to be connected to a compatible charger? I don't see how it could it be functional with my PD4655?

In view of the potential for a portable solar panel in the future, is there anything else I should consider now or in the future?

Thanks in advance,
Mike

I changed out two 12 volts for two 6 Volts on my 25' Flying cloud. Got them on the internet for $200 a piece and they're AGM's. Didn't have to change the size of the box either. Just got my 27' Globetrotter and had the dealer put the 6's in them. Work great with 160 solar panels.

[blkmagikca]

Chances are that your charger/convertor is a single stage one, and they tend to boil out the batteries. So, before spending money on a set of batteries that will be dead in 3 years, consider upgrading to a multi-stage charger. Then look into AGM batteries - Lifelines or Pearl River (both have long warranties).

[uncle_bob]

Originally Posted by blkmagikca

Chances are that your charger/convertor is a single stage one, and they tend to boil out the batteries. So, before spending money on a set of batteries that will be dead in 3 years, consider upgrading to a multi-stage charger. Then look into AGM batteries - Lifelines or Pearl River (both have long warranties).

Hi

Not true on a trailer made in this century ....

Bob

[GMFL]

Originally Posted by uncle_bob

Hi

Not true on a trailer made in this century ....

Bob

Bob,
Not tire. Single stage chargers are very common in new er Airstream’s. My 2014 had one and I changed it out after the factory one burned up one of my batteries.

[marter]

Originally Posted by blkmagikca

Chances are that your charger/convertor is a single stage one, and they tend to boil out the batteries. So, before spending money on a set of batteries that will be dead in 3 years, consider upgrading to a multi-stage charger. Then look into AGM batteries - Lifelines or Pearl River (both have long warranties).

In my post starting this thread, I stated in bullet #2 that I changed out my converter/charger to a PD 4655, which is a 4 stage, and one of the most recommended units on these forums.

I'm happy to almost triple my AHs to 215 for what I paid. And I could do it again for less than the cost of 2 AGMs. I'll see how long they last and consider the options then.

Happy trails,
Mike

[TouringDan]

Originally Posted by marter

I'm happy to almost triple my AHs to 215 for what I paid. And I could do it again for less than the cost of 2 AGMs. I'll see how long they last and consider the options then.



Happy trails,

Mike

My two 6v golf cart batteries from Sam’s Club are 7 years old and doing fine. I check the water level about once or twice each year. I like to keep things simple. No automatic watering for me.

Dan

[Vantair]

Recently spoke with a US battery manufacturer Senior managing engineer for 45 minutes on AGM vs wet cell and golf carts. He admitted they were the previous OEM manufacturer of Interstate batteries for Costco.

According to him, they recently lost this contract to another provider but has learned of many more returns, concluding these deep cycles, are not a “true” deep cycle but a modified/hybrid starting battery (thinner lead plates) internally yielding less storage or lifespan.

This was a little disappointing so went the 6v AGM group 27 route at 72 lbs each with our fresh PD 3/4 stage converter.

Besides the packaging, price and great Costco warranty, who’s going to know after few years right ? Perhaps comparing weight of battery types may tell..... still do LOVE our local Costo !

[tjdonahoe]

Why go to all that trouble for very little gain if any....

[mfrez]

Research the Trojan T105-RE. https://www.trojanbattery.com/pdf/da...ata_Sheets.pdf

6v deep cycle wet cell made specifically for RV's. I bought 2 of these 2 years ago and have been extremely happy with them. We boondock alot and including running the furnace (we have the factory Zamp solar system), the only time I have to use my generator is when the wife wants to pull her hair dryer out.