RV Modifications Part 8: Suspension and Lithium Battery upgrades

December 10, 2021

RV Modifications Part 8:  Suspension and Lithium Battery upgrades

The handling of our Winnebago View has generally been controlled and comfortable, but entering and exiting driveway curbs can set up disturbing sway which can cause quite a clattering in the coach.  After researching Sprinter chassis suspension modifications, I decided to install Sumo Springs, which are solid polyurethane blocks that replace the factory bump stops, and add progressive spring force to the suspension.  Dampening sway can be accomplished by increasing spring tension, increasing shock dampening, and by distributing the forces with sway bars.  Cost and time-wise, swapping out the factory bump stops for Sumo Springs was quick and inexpensive.  It took less than 2 hours to do the installation of both front and rear Sumo Springs.  What took the most time was jacking up the chassis to unload the suspension at each corner of the vehicle.  I used a 20 ton hydraulic bottle jack and wood blocks.  Installing the rear Sumo Springs just involved twisting out the factory bump stops with a long screw driver, and then sliding and poking in the retaining flanges of the Sumo Springs into the brackets on the chassis that held the bump stops in place. The front Sumo Springs required removing a nut and washer to get the factory bumpstops out, and a little careful maneuvering of the Sumo Springs into position so that the bolt in the top of the Sumo Spring was aligned properly in the hole that the original bump stop used.  Then it was a simple matter of tightening the washer and new nut.  

While I was installing the rear Sumo Springs I also discovered that the bolt and nut connecting the driver side factory sway bar to the chassis was missing, effectively eliminating the function of that sway bar.  So I replaced the missing hardware, which was 12mm class 10.9 hardware.  

These suspension modifications will hopefully tame those driveway entries and exits.

On our last boon docking trip, our flooded cell lead acid batteries dropped to below 10V overnight with just the refrigerator and furnace loads, so I ordered a pair of 100AHr Renogy LiFePO4 RV batteries that come in group 31 standard battery cases that are drop in compatible with the existing battery box.  The batteries are not the latest design which features pouch cells but has aluminum encased rectangular cells and built in Blue-Tooth battery management system monitoring.  There was some extra space in and around the battery box, so I installed 2" high density insulating foam blocks to insulate the battery from the outside temperatures.  The original flooded lead acid batteries were essentially mounted outside the coach to allow hydrogen to vent to the outside, but the new LiFePO4 batteries need no venting, and are sensitive to temperature extremes.  They can't be charged if they are below freezing, so by building an insulated box around them, thermally connected to the interior of the coach by the uninsulated lid, we should be able to maximize our ability to use these new batteries to their fullest potential. 

I also purchased a Power Watch Dog RV surge and voltage protector that can disconnect the RV from a power pedestal if the voltage is either too low or high, and to absorb any dangerous surges.  This particular unit also comes with a bluetooth monitoring app and the surge suppressor module is user replaceable.  

These upgrades to the electrical system will hopefully give us the ability to maximize our ability to optimize power usage and avoid damage to any of the RV's electrical components due to power issues, for which RV parks are notorious for.