Stark Power Lithium Battery Upgrade for the Travato

Well this project was a long time in coming.  I hemmed and hawwed about it for a long time.  Was it worth the trouble and expense?  Did I really need the extra capacity?

I finally rationalized that it was.  Effectively, replacing my two Group 31 AGM batteries, I'd go from 110 ah of usable capacity to 225 ah and save 80 pounds of weight.  These new lithium ion batteries are actually LiFEPO4 batteries.  There are many different types, but this is what is going in all the RV's currently and many electric cars.  They are very safe for this use and are a different chemistry from the ones that caused fires in airliners and kid's hoverboards.

On my last battery project, I used the Smart Battery.   I changed over to the Stark Battery for several reasons.  First, the capacity is much higher - 125 ah compared to 100 ah.  Second, they have a much more sophisticated BMS.  Actually, the Smart Battery does not have a true BMS.  This one has thermal protection (high temp), as well as voltage protection, and cell balancing.  Third, the technology is different.  They use prismatic cells as opposed to the cylindrical cells.  All the batteries you'll find for RV application are prismatic.  My understanding is that it's a simpler design and results in a smaller overall package.  Fourth, and finally, the Stark battery is smaller and you can unscrew the top and get to the insides (the Smart Battery was sealed - you'd have to cut it open - yikes!).  I thought this might be handy, if in the future I want to put a temperature sensor inside.

With all that said, here is what arrived on my doorstep via Fedex.   It took 4 weeks from order to receiving my batteries.   Apparently, they make the various sizes of batteries in batches, so if one batch is gone, you have to wait for the next.  Turns out that bass fishermen love these things for their trolling motors - they were just cleaned out when I placed my order.   Here's another thing I like about Stark - their battery came well packaged in an actual box.  The Smart Battery came via a guy in a panel van - no box, no nothing.  Just handed me the battery, there ya go buddy.  Odd.

I like these Stark people.  The are just up the road from me in Charlotte, NC.

This is the label sticker.  Two things I think are in error.  The weight is much less than 39 lbs - more like 32.  Second is the initial charge.  The resting voltage I measured was 13.4 volts. That's a LOT more than 70%.

This is first rate packaging.  Lots of cushioning and room around the item in case the box gets beaten up - which one of mine was.

So, out to the shop and get this project going.  First is to raise the van up on my home-made ramps to get the old batteries out.  Love these ramps!

Here's one of the new batteries mounted to the slide-out tray.  It's well secured with the bar, but you don't want to tighten it too much or you may crack the polystyrene case.

These shots I took to show the difference in size between the Group 31 and the Stark Battery.  This will pay off later as I'll show you.

Side by side.

Inside the van (a Travato 59K), the converter/charger unit is located on a shelf under the curb-side bed.   Two tricks to not making that alot of work - using a screw gun with a long shaft screw bit - and not removing the bed deck from the van or all the Froli springs.  Just unscrew the deck, and slide it over until you uncover the converter.

Here's what you get from Winnebago these days - Progressive Dynamics PD9245C smart charger/converter.  Uses 725 watts and 4.5 amps.  You want to stick to these numbers so that you are not severely altering your electrical loads.  Otherwise, you may see some undesireable behavior with the EMS.  You could go over 30 amps under certain conditions and it will start shedding loads.  Also, if you increase the charging amps, you may also need to upgrade the wiring - a much more involved project since these wires snake around the bowels of the van and out thru the bottom.   I don't need such quick charging that I want to go to all that expense and trouble.

The wiring is really simple.  Two leads for the batteries, and a ground wire.

This item I had left over from my last project - the Progressive Dynamics Lithium Converter Charger model 9145L.  This is the same device you'd get in a Pleasureway Lexor with the new lithium setup.   What's cool about this device, is that dimensionally it is exactly the same as the 9245 that came with my van.  Also, all the wiring is the same, and the screw holes to mount it are the same as well.  So this change out is about as easy as it gets.  Also, since the electrical loads are the same, it will not effect my EMS.

Here it is mounted in place and ready to button it all back up.

Here she is under the van all mounted and secured.  Note that there is room around these batteries.  I think a project to install a temp sensor and insulate these batteries would be pretty easy so they could be used (charging) in cold weather (teens and twenties F).  You could even fit heating pads, as there is so much room.

Another thing to consider, since these batteries are so small, if you were so inclined, I think the bracketry could be reconfigured to enable mounting 4 batteries.  You have four large bolts hanging down from the floor of the van, sized to support two 76 lb batteries and the steel brackets.   If you could have new brackets made, you could possibly mount four of these batteries in this space.

Currently, I'm not using an inverter, so I'm undecided if I would want to go that far.  Something to think about in the fall I guess.