Chosen Solution

2018 Mercedes Sprinter 2019 Winnebago Revel Original owners. This RV does NOT have a generator. It does have 200w of solar panels. ZS 30A zamp solar controller. 2000w inverter. progressive dynamics converter #9245. 3 100 amp hour interstate marine deep cycle … dual purpose batteries 200 reserve capacity each. They are mounted under the vehicle and weigh too much for us to mess with! New this month! OUCH $500 each even though interstate charges direct customers $399.! 4 trips 8 man hours just shuttling! Went a couple of times to pick up our vehicle, ..not fixed. We hadn’t t used it much with the original batteries however. We thought the problem was the coach batteries. Went to Winnebago approved service center, had them replaced. Same issues. We know 50% is the max amp hours we can get out of the AGM batteries. If we turn anything on for less than a minute or 2 things go sideways! BTW. Had our old batteries load tested after they were removed and they are good. When we turn on the refrig with a fully charged battery bank the refrig makes too much noise. the Zamp controller shows 11 ish volts. (great NOVAKOOL refrig… very quiet and never a problem with it. Equivalent of less than 40w bulb) If we are on shore power, it is very quiet and works fine. Something seems to be amiss…. Grounding? short? If we turn on 3 led lights at the same time - reading is 11 ish or below (FULLY CHARGED) After attempting “approved service centers” we are starting to understand that we have to figure it out! Have taken a few trouble shooting steps. Want to take more, so am reaching out here to see if anyone is familiar with this particular vehicle. I think we have been the experiment…. newer models have nifty things like a solar shut off switch (we have to unplug solar on the roof if we don’t want the panels feeding in). Newer models have % of charge monitors for the batteries. Our model has the zamp controller, and a “one place” that shows Volts. Lots of folks are ripping out brand new systems in these to put lithium batteries in. Newer models come with Lithium batteries. We hear they have their own set of issues. For me … there is NO WAY I want to sleep above a bank of batteries. We need help and hand holding taking the troubleshooting one step at a time.WB TABLE OF CONTENTS Electrical

Hi @nan_c Just curious whether the Progress Dynamic controller is charging the batteries at the correct rate. Maybe check the voltage across the battery terminals when they’re being charged. if it is undercharging, this might explain the quick voltage drop to 11V when under load. If the charging voltage is OK then when the batteries are being used to supply power to the vehicle, try pulling the fuses (breakers?) one by one and check if the voltage goes back up from 11V to hopefully isolate which circuit is dragging it down. Without a schematic, just some things I’d check first. Update (07/15/2022) Hi @nan_c I’d worked out before about the “hot links” in the manual you uploaded but the schematics were in a format that I’m not used to. Never come across schematics where you had to “search” for the other end of a wire. Usually they’re fully drawn out or have reference points to tell you where it is, not just a wire colour (if that’s what it is). According to the 2018 model 12V wiring diagram you linked the LP detector is on fuse #7 in the 12V panel. It is not shown anywhere else on the diagram, although assuming that a “WB” (White/blue?) wire is run to the fuse from it, the only other mention of a “WB” on the diagram is for the switch designated as “CL” in the diagram which is located below the sink - see image

(hover your cursor over the image and then click on the magnifying glass icon that appears to enlarge, then click on the newly opened image again to enlarge further) What is fuse #7 designation in the fuse box in your van, LP detector or perhaps toilet? (Is there a toilet in your van?) Is there a switch under (inside the cabinet?) the sink as shown in the image as “CL” and what is it used for? Is fuse #7 powering whatever is connected to the switch? (remove the fuse if unsure to prove it). I don’t think that it will be the LP detector as it is a safety device and usually these aren’t wired so that they can be disabled by a switch (inadvertently or deliberately). If there is a problem (alarm?) with them then the power is removed by taking out the fuse but only after verifying that there isn’t a gas leak. Not sure what LP detector means but am assuming it is a LPG (liquified petroleum gas) leakage detector but maybe it means something else where you are e.g. low pressure?? I don’t know Only asking all this because in the 2020 model 12V wiring diagram I linked, is that fuse #7 is for the toilet, it has a WB (white/blue wire colour?) notation next to it, but there is no other mention of WB (or Switch detail CL under the sink) and there is no mention of an LP detector and the diagram for the 2018 model doesn’t mention the toilet. This is not to say that the fuse can’t be used for something else etc.

(click on image to enlarge). Talk about confusing??? Update (07/15/2022) Hi @nan_c and @brandon_k Looking at the manual for the Novakool current refrigerator series from 2018, from this link it seems that the Novakool refrigerator may be a dual voltage model. (both AC and DC) (see wiring diagram on p.5 of 8 {pdf numbering} of the manual) and not just works on AC supply only as I thought it might do i.e. AC from inverter supplied by battery or solar So perhaps there is a problem with it when on DC as the AC/DC module is in the fridge! What is the model number of the refrigerator @nan_c, so this can be verified? If it is a dual voltage model, check that the DC voltage and connections are correct at the refrigerator and maybe also the 12V DC fuse #10 (and fuse wiring) in the 12V panel. Check the DC wire gauge size (example only) especially relating to distance from the 12V fuse panel and the -ve or earth wiring as per p.4 of the manual. The -ve wire may not be run all the way from the battery, it may be connected to a convenient chassis earth point as the battery -ve terminal may also be connected to the chassis. The +ve wire should run to fuse #10 in the 12V fuse panel (if the van wiring diagram is correct although it shows a 10A fuse and the fridge manual shows a 15A fuse). If they’re all OK it may be the refrigerator. According to the manual there is a limited 2 year warranty on it so something to bear in mind if you can’t find anything wrong with the DC power to the refrigerator.