Battery Question

[Bobo_Wickersham]

I'm looking at replacing my house battery, and not ready to go with lithium yet. I've had some exposure to Concorde SunXtender batteries, with very low internal resistance they seem suited to make the most of the solar panels that came on the coach.

The battery distributor has recommended to replace the 4 strings of 2 x 6 volt batteries with one string of 2 volt batteries, increasing the AH rating from 800+ to 900+. This also eliminates parallel strings, which can introduce variations in the charging current for each battery, and makes troubleshooting a weak battery very easy.
They will fit in the tray, same GC2 size but only 6 cases rather than 8. Also they should be lighter, so less cost to drive around.
I'm wondering if any of you have heard of this before, or seen it?

The SunExtenders that will fit in the tray (6V) are PVX-2240T, the (2V) batteries are PVX-9150T

[Vickie 4369]

Originally Posted by Bobo_Wickersham

I'm looking at replacing my house battery, and not ready to go with lithium yet. I've had some exposure to Concorde SunXtender batteries, with very low internal resistance they seem suited to make the most of the solar panels that came on the coach.

The battery distributor has recommended to replace the 4 strings of 2 x 6 volt batteries with one string of 2 volt batteries, increasing the AH rating from 800+ to 900+. This also eliminates parallel strings, which can introduce variations in the charging current for each battery, and makes troubleshooting a weak battery very easy.
They will fit in the tray, same GC2 size but only 6 cases rather than 8. Also they should be lighter, so less cost to drive around.
I'm wondering if any of you have heard of this before, or seen it?

Attachment 274472The SunExtenders that will fit in the tray (6V) are PVX-2240T, the (2V) batteries are PVX-9150T

I just replaced my 8 220 AH lead acids with 8 300 AH Lifeline AGMs great compromise between Lead Acid and Lithium.

Great reviews and now I have 2400 AH or 1200 AH at 50% discharge.

Also replaced the crappy straps with ratchet straps using the original clips.

Straps Not shown in this picture but link below

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[Mark_K5LXP]

Originally Posted by Bobo_Wickersham

one string of 2 volt batteries, increasing the AH rating from 800+ to 900+.... they should be lighter, so less cost to drive around.

I didn't dive into the data sheets but one of the things I'd review is a comparison of capacity at different discharge rates and see how it tracks vs a bank of GC-2's. There can definitely be an efficiency boost with a different cell configuration, but there ain't no free lunch. Generally Ah tracks pretty closely to lbs of lead so a lighter pack will generally have less Ah. The data sheets will show you how the performance curves compare.

Mark B.
Albuquerque, NM

[Dutch Star Don]

Originally Posted by Vickie 4369

I just replaced my 8 220 AH lead acids with 8 300 AH Lifeline AGMs great compromise between Lead Acid and Lithium.

Great reviews and now I have 2400 AH or 1200 AH at 50% discharge.

Also replaced the crappy straps with ratchet straps using the original clips.

Straps Not shown in this picture but link below

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I agree with the above. My 2014 DS came with six lead acid batteries and my 2019 DS came with eight AGM batteries. I was glad to get rid of the lead acid and having to deal with watering the batteries.

For us, we primarily use campgrounds with hook ups. On the few occasions that we boondock, the AGM's do a good job, supported by 450 watts of solar.

So...…..you need to determine your camping habits and decide if you really need anything exotic or just go with eight new AGM's.

[Scottybdivin]

Originally Posted by Vickie 4369

I just replaced my 8 220 AH lead acids with 8 300 AH Lifeline AGMs great compromise between Lead Acid and Lithium.

Great reviews and now I have 2400 AH or 1200 AH at 50% discharge.

Also replaced the crappy straps with ratchet straps using the original clips.

Straps Not shown in this picture but link below

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Correct me if I'm wrong, but aren't your 300Ah Lifelines still 6V? If so you have 1200 Ah at 12V. Still that's a nice upgrade. I wanted to use them but I didn't have the headroom to accommodate them. My only choice was to modify the tray from 6 to 8 GC2's to get 900 Ah.

[twinboat]

Originally Posted by Vickie 4369

I just replaced my 8 220 AH lead acids with 8 300 AH Lifeline AGMs great compromise between Lead Acid and Lithium.

Great reviews and now I have 2400 AH or 1200 AH at 50% discharge.

Also replaced the crappy straps with ratchet straps using the original clips.

Straps Not shown in this picture but link below

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

You have 1200 AH of capacity with 8, 300 AH 6 volt batteries.
Each series string double volts but not AH capacity.

If you running them down 1200 AHs, you are running them down 100%.

[followingsea]

Originally Posted by Bobo_Wickersham

The battery distributor has recommended ...

What do you need?

Is this one of the cases where someone selling something you do not need.

It looks like you have a nice set to boondock with children but if you spend most of the time full hook, you are hauling a lot of weight you do not need.

Generally speaking 4 GC2 6 volt batteries will take care of your needs. $400 at Sam's club.

[Vickie 4369]

Originally Posted by twinboat

You have 1200 AH of capacity with 8, 300 AH 6 volt batteries.
Each series string double volts but not AH capacity.

If you running them down 1200 AHs, you are running them down 100%.

You are correct it was merely a late night brain fart.

So I had 880 AH of which I could use 440 AH at 50% discharge

I now have 1200 AH of which I can use 600 AH at 50% discharge.

Sorry for the confusion.

Ted.

[Bobo_Wickersham]

Originally Posted by Mark_K5LXP

I didn't dive into the data sheets but one of the things I'd review is a comparison of capacity at different discharge rates and see how it tracks vs a bank of GC-2's. There can definitely be an efficiency boost with a different cell configuration, but there ain't no free lunch. Generally Ah tracks pretty closely to lbs of lead so a lighter pack will generally have less Ah. The data sheets will show you how the performance curves compare.

Mark B.
Albuquerque, NM

That was a great point you made about weight & lead. The 6 x 2v batteries weigh more than the 8 x 12v
batteries, 564lb. as opposed to 536lb. It may be that just a 6 volt batteries are chosen for a more rugged plate design than 12 volt batteries, 2 volt batteries
may have longer life yet. Hoisting these 94lb. batteries into the tray will be close to a 2 person job.
This looks like a tall GC2 case, which must be how

[Bobo_Wickersham]

Originally Posted by Vickie 4369

I just replaced my 8 220 AH lead acids with 8 300 AH Lifeline AGMs great compromise between Lead Acid and Lithium.

Great reviews and now I have 2400 AH or 1200 AH at 50% discharge.

Also replaced the crappy straps with ratchet straps using the original clips.

Straps Not shown in this picture but link below

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Thanks for the link to new hold-downs!
One of the things I've had trouble sourcing is copper link bars, bus bars, sometimes called straps,
for revised battery configurations. I like the ?Newmar OEM bars, but have not had much luck sourcing them. Has anyone run into this before? Or just gone with
custom crimped cable links?

[Vickie 4369]

Originally Posted by Bobo_Wickersham

Thanks for the link to new hold-downs!
One of the things I've had trouble sourcing is copper link bars, bus bars, sometimes called straps,
for revised battery configurations. I like the ?Newmar OEM bars, but have not had much luck sourcing them. Has anyone run into this before? Or just gone with
custom crimped cable links?

I made 2/0 cables you can see them in the picture I posted.

I found the material to make them at McmasterCarr but it is expensive, others purchase 1/2 in copper tubing roll it flat cut and drill it.

I felt the cables were the best option, I have a hydraulic 6 sided crimper with all the dies so it was a breeze.

[LWBAZ]

Several points for your consideration:

1) Concorde SunXtender batteries are made by Lifeline.

6 Volt SunXtender PVX-2240T = 6 Volt Lifeline GPL-4CT
6 Volt SunXtender PVX-3050T = 6 Volt Lifeline GPL-6CT
2 Volt SunXtender PVX6720T = 2 Volt Lifeline GPL-4CT-2V
2 Volt SunXtender PVX9150T = 2 Volt Lifeline GPL-6CT-2V

2) Installing six 2 volt batteries in series will work, yielding a bank that outputs 12 volts. One disadvantage is that if a single battery fails, you’re out of luck until you can locate a replacement. And 2 volt batteries are significantly less easy to come by than 6 volt batteries.

3) When you use 2 volt batteries to create a 12 volt bank, you have to install them in multiples of six. With 6 volt batteries you can install them in multiples of two.

4) With your battery tray, you could go with any of the following options. I’ll use the Lifeline product numbers, but you could use the equivalent SunXtender batteries if you so desire.

Six Lifeline GPL-4CT’s – Rated Capacity = 660 Amp Hours at 12 Volts (20 Hour Rate)
Six Lifeline GPL-6CT’s – Rated Capacity = 900 Amp Hours at 12 Volts (20 Hour Rate)
Eight Lifeline GPL-4CT’s – Rated Capacity = 880 Amp Hours at 12 Volts (20 Hour Rate)
Eight Lifeline GPL-6CT’s – Rated Capacity = 1200 Amp Hours at 12 Volts (20 Hour Rate)

The GPL-4CT’s weigh 66 pounds apiece, so six of them will weigh 396 pounds and eight of the will weigh 528 pounds.

The GPL-6CT’s weigh 90 pounds apiece, so six of them will weigh 540 pounds and eight of them will weigh 720 pounds.