Thor Forums

Thor Forums (https://www.thorforums.com/forums/)
-   Modifications and Updates (https://www.thorforums.com/forums/f27/)
-   -   Adding extra coach betteries (https://www.thorforums.com/forums/f27/adding-extra-coach-betteries-9243.html)

Jeff From Iowa 33sw 09-14-2017 07:29 PM

Adding extra coach betteries
 
Anyone added extra coach batteries? I'd like to add 2 more andhadhoped to do it right by the others but the exh is too close. Has anyone else added some? If so where.

I'm a welder fabricator, itlools likebehind the axle on the frame is best.

Thanks jeff.

Mike in AZ 09-14-2017 08:01 PM

Quote:

Originally Posted by Jeff From Iowa 33sw (Post 88275)
Anyone added extra coach batteries? I'd like to add 2 more andhadhoped to do it right by the others but the exh is too close. Has anyone else added some? If so where.

I'm a welder fabricator, itlools likebehind the axle on the frame is best.

Thanks jeff.

Your profile says "still looking," what model and year coach are you asking about?

Bob Denman 09-14-2017 08:15 PM

:D Perhaps the "looking part" is over... :thumb:
What'd you buy??? :coolsmiley:

Jeff From Iowa 33sw 09-14-2017 08:21 PM

My model is in my user name.

99dart 09-14-2017 08:55 PM

From looking at your floor plan it is very similar to myWS31. Are your batteries under the second step? My battery box will fit 4 batteries. But, 6v units are really close on height.

Jeff From Iowa 33sw 09-14-2017 08:59 PM

I can only fit the two. There. I have f 550 chassis w a diesel.

99dart 09-14-2017 09:02 PM

Ah, OK. Being a fabricator, I'll bet you come up with a good solution. :thumb:

Jeff From Iowa 33sw 09-14-2017 11:10 PM

Yes install is not a issue was hoping people would chime in about how many they added etc. I have residential fridge. It will not make 12 hours with two big batteries.

99dart 09-14-2017 11:43 PM

I'm in the same boat with you there! I have already done the fitting and wiring adjustments to install 2 more 6v batteries in mine. I hope 4 will be enough until I can install some solar support to the charging system.

Jeff From Iowa 33sw 09-14-2017 11:43 PM

That's a good idea. My rig had solar and someone removed it.

Jeff From Iowa 33sw 09-15-2017 02:26 AM

Why are you messing with 6 volt batteries?

2-12 in parallel is what they install. You still only see 12 volts but have more reserve time.

gmc 09-15-2017 11:23 AM

Quote:

Originally Posted by Jeff From Iowa 33sw (Post 88342)
Why are you messing with 6 volt batteries?

2-12 in parallel is what they install. You still only see 12 volts but have more reserve time.

Actually many use two 6 volt batteries in series... Or four in series/parallel... In all cases providing 12v to the coach.

6v batteries tend to be more 'energy dense' and can provide more capacity in the same space.

Making the assumption that what is installed by factory is best option is probably not valid in MANY cases.... Batteries, power converters, TV's, etc all come to mind...

Some rigs do come with 6v batteries too.

Jeff From Iowa 33sw 09-15-2017 02:07 PM

Hmm mine has six volt. I don't see reserve capacity on them.

What's the reserve capacity for your 6v?

I'd be willing to bet I can gain a lot by removing the 6v and installing my two 12volt agm 155 reserve minute batteries.

TyCreek 09-15-2017 02:31 PM

If you're adding batteries to existing storage, any mismatch is less than optimal for long cycle life. Best is when all batteries are matched. Even the same batteries are not matched when part of the array is aged. The good news is parallel connections are more tolerant for mismatch.

Since you have a new coach, your batteries "might" be ok. I say might because sales lots can be really hard on batteries and age them early. Assuming your factory batteries are 95% or better, the best option for "adding" batteries is to get the same batteries to put in parallel.

Consider your interconnect cable lengths and how they affect your charge/discharge cycles. Matched batteries can become very unmatched due to long cable run losses.

One way to increase capacity is by going to a denser power chemistry and drop in replacements are becoming more available. The LiFePo4 drop-in options provide a much better DOD and eliminates the importance of 3 stage charging. DOD is depth of discharge and that means you get to use more of the battery's capacity without degradation (think near 90% vs. 50% for FLA). Really the only downside is the initial sticker price! Long term however they could very well be cheaper YMMV.

jpmihalk 09-15-2017 02:34 PM

We added 2 more 12V batteries for a total of 4, then upgraded to AGM batteries for the additional reserve capacity plus more flexible charging and zero maintenance. We also have 400W of solar panels to keep those batteries charged during daylight hours. Our Hurricane already had the space in the battery compartment for 4, so I can't speak to creating trays, etc. for adding batteries.

99dart 09-15-2017 02:36 PM

I have learned from reading here that you want the highest Amp Hours per battery. Two six volt in series create more amp hours than two 12v in parallel. (I hope I said that right)

Mike in AZ 09-15-2017 02:38 PM

Quote:

Originally Posted by Jeff From Iowa 33sw (Post 88290)
My model is in my user name.

Oh, sorry, duh! :facepalm:

16ACE27 09-15-2017 02:52 PM

Quote:

Originally Posted by Jeff From Iowa 33sw (Post 88381)
Hmm mine has six volt. I don't see reserve capacity on them.

What's the reserve capacity for your 6v?

I'd be willing to bet I can gain a lot by removing the 6v and installing my two 12volt agm 155 reserve minute batteries.

"Reserve minute" is an inaccurate rating. You need to know the capacity of the battery in Amp-Hours, normally rated at 20 amps.

And given the same chemistry and physical size, two 6 volt batteries in series normally has a larger capacity than two 12 volt batteries in parallel.

wenzOmatic 11-18-2017 04:48 PM

Quote:

Originally Posted by Jeff From Iowa 33sw (Post 88381)
Hmm mine has six volt. I don't see reserve capacity on them.

What's the reserve capacity for your 6v?

I'd be willing to bet I can gain a lot by removing the 6v and installing my two 12volt agm 155 reserve minute batteries.



On the interstate page for RVs they list the 12v as 220 Amps and the 6v as 447 Amps. My battery box is 27 1/2 x 14 1/2 looks like it would take 4, 12vdc (840 total) batteries if turned sideways or 2, 6vdc (894 total).

Looks like the 6vdc would beat out the 4 12 vdc batteries.

What am I missing?

wenz

Chance 11-18-2017 05:34 PM

Quote:

Originally Posted by 99dart (Post 88386)
I have learned from reading here that you want the highest Amp Hours per battery. Two six volt in series create more amp hours than two 12v in parallel. (I hope I said that right)


It's not that simple because Amp-hours IS NOT a measure of energy.

For example, 100 Amp-hours at 6 Volts is only half the "energy" as 100 Amp-hours at 12 Volts. And if we used a 48-Volt system like in many residential solar applications (and auto future) the difference (error) is even greater.

The best way to actually simplify these calculations is to use units of measure for energy, which for batteries is normally kWh (kilowatt-hour). That's how electric cars are rated because Amp-hours would be useless without also knowing voltage. RVs are "usually" 12 volt systems, but even that confuses a lot of people because batteries can be 6- or 12-Volt.

When you look at actual energy storage capacity of batteries, assuming same chemistry and battery weight, there is very little difference between 6- and 12-Volt batteries.

There is usually a "slight" advantage for the 6-Volt over 12-Volt because each cell is larger, requiring a little less packaging per pound of battery. If we only cared about maximizing Amp-hours per battery, we'd go to 2-Volt batteries. ;)


All times are GMT. The time now is 08:29 AM.

Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0 PL2