More batteries

[bratworst]

It says "Lithium Ion" on the batteries.

[Scalf77]

Originally Posted by ilovegt100

Hey guys,

That battery box is mine and is wayyyy overkill but works like a charm. They are lithium iron phosphate not lithium ion like the smoldering Dreamliner ones.

Ilovegt100

Actually they are both Lithium Ion batteries, The Dream liner batteries are Lithium Cobalt Oxide(LiCoO2) cathode, while the Smart RV battery is as you said Lithium Iron Phosphate(LiFePO4) cathode. The key benefits are enhanced safety, good thermal stability, tolerant to abuse, high current rating and long cycle life. They of course get there by losing performance seen in other Lithium Ion based designs, but those trade offs are better for a RV battery.

I have been looking into these, but the cost has been a big factor in not going there. I also was hoping to get more real world reports on results. , so please keep us updated on how well they perform.


llamadave

Have you looked at the possibility of a separate second bank of a different size. Instead of paralleling both banks together, you would switch to the aux bank when the primary got low. This could be done using a Blue Sea m-Series Mini Selector Battery Switch 6007.

-greg

[llamadave]

Thanks, Rob and others. I think I will stick with AGM group 27. It indeed would be a lot of work to install the batteries up front and run the cables to the back. There is room in the back forward of the spare tire for two more batteries if I use trays and not vented boxes (click on Vanessa below for diagrams of my van).

I have spent a couple of hours reading posts in many forums about need for venting AGM batteries. About half say it is ok to have open batteries in the living space and half say it is a risk because the charging system could go bad and release hydrogen. There will also be problems if one battery develops a short circuit. I am thinking this an acceptable risk, probably much less risk than say destroying the van in an accident. I will need to protect well the terminals from shorting by things I stow in the back, and I will not leave the van charging unattended for long periods.

I should note that, in our one battery box that SMB put above the floor, the cables come out a hole in the top side of the box and there is lots of open space around the cables for gasses to leak into the living space instead of going out the vent tube.

Comments on this new unvented plan are welcome.

David

[daveb]

But wow I'd love to have those batteries

[ilovegt100]

Gl with ur build. My 600amp battery pack was just presented for counterpoint. Their chemistry does not require venting but I put in venting anyways just in case. They work very well for my application. Eventually I would like to replace the starter battery with the same type and will likely add a second starter battery once they are the same type using the oem 2nd battery mount. I will keep you guys informed if I go up in a burst of flames

Ilovegt100

[bratworst]

Are you using a Power-Mite belt driven generator to charge those batteries?

[ilovegt100]

Yes... belt driven but just an American Power custom alternator. It puts out about 15v and I have a voltage regulator set to limit it 14.6 constant to the batteries.

[rob_gendreau]

Re venting, many of the installations I've seen look sort of problematic, and I'm not sure how effective they'd be with significant gas emissions. Hydrogen would rise, and some of those tops don't exactly seal airtight. On the other hand, a H soaked gaucho wouldn't be nice when you lit a cigar. It's just I'm not convinced the standard battery boxes would help that much.

I'm thinking of putting a layer of PVC just under the gaucho and plastic sides by the batteries, and just leaving the vent hole open with a very short hose bent up a bit to prevent rain from entering. The idea is to isolate the batteries from stuff falling on them and having some air circulation. The amount vented from an AGM would be small and it would be significantly diluted. I'm not super worried about it; certainly seems safer than the flooded lead acid that came with the van.

Rob

[llamadave]

Thank you for all your comments and thank you Chad at SMB Indiana for suggesting a third alternative location. I could fit two more batteries in the back compartment only if I did not put in sealed vented boxes and from your comments and web searches I decided that this is not worth the risk and not worth losing the storage space. Putting two batteries in the engine compartment was a very tight squeeze and would be a costly headache when MBz wanted to access the computer and would cost $$$ in cable going to the back.

So I talked to Chad. I enjoy talking to everyone at SMB Indiana and Chad is the best with lots of practical information. He suggested finding a place under the van for the batteries. I spent some time under there and found they would fit nicely between the diesel generator in the back and the rear axle. I have designed a steel cage that I plan to weld together to hold them. I purchased the two batteries (Deka Intimidator 8A27M, same as the first two) and welding cable and battery boxes from http://www.remybattery.com). I will put the battery boxes upside-down over the batteries. I will buy a TECA hoist/winch normally used for spare tires to lift the cage into position (150 lbs) then bolt the cage to the frame using the MBz original spare tire brackets. It will be fairly easy to lower it to maintain the connections or install new batteries.

I will install a off/1/2/all switch so I can charge just two at a time when driving to keep a heavy load off the Sprinter alternator when the batteries are run down.

I will post photos and details after it is installed in a few weeks. Total cost? Less than 1% of the SMB, and will double the battery capacity and will not use up any of our storage space.

I can show you this and all the unique Vanessa features at the Meet and Greet in Jackson Hole June 21.

David

[llamadave]

To conclude this topic, I posted some details on my very successful battery installation here.

David