2018 Sprinter Battery Drain - Page 2

Scalf77 · 03-13-2019, 04:48 PM

Sorry to not explain myself correctly, I was interested in what the voltage was after you charged (minus surface charge). 0.2 amps is large load, doesn't sound right to me. You would be loosing 4.8 Amp-hrs per day, 33.6 Amp-hrs per week. What size is the starting battery? We are talking about a Winnebago Revel correct? They do show a solenoid in their electrical drawings, I expect that is what charges from the house battery when your driving. If you replace the solenoid with a ACR you would be able to charge from Solar & Shore if needed. What size alternator does the sprinter have?

I would really go to the RV dealer and have them explain why the load is so high. That is the real culprit, that is similar to the draw of my CO & LP detector. I suspect that your battery is not in good health if you have drained it multiple times. A hybrid starting AGM would only help, but would last longer. Installing a bidirectional ACR would allow you to charge from solar and shore, but still masking the real problem. Winnebago list a couple of vendors for possible isolators/separators, a picture of the one installed might give us an idea on how to make it work for you?

greg

rean1mator · 03-13-2019, 05:06 PM

Yes, It's a revel.

Yeah, I charged it up with a fast charger yesterday, let it sit overnight so surface charge would be gone, disconnected the chassis battery disconnect as well right after the full charge. Late this morning it was reading 12.38V. that's definitely not right.

RV Dealer said that the .2Amp draw was normal. I thought it was way too high myself. Starting Battery is around 100 amps and is a dual purpose AGM I believe.

My initial thoughts were that there's something in how it's wired up from Winnebago that is not correct. But everyone seems to think 2 Weeks until battery getting drained is normal? I do not.

I'm taking it in to Mercedes Dealer tomorrow to get the battery replaced and will ask them about the .2A draw that RV dealer measured and ask if it's normal.

Will report back after I talk to the dealer.

For now I'm going to just wire in a quick connect cable lead for my battery tender and just leave it plugged in until I figure out if I want to install the ctek setup for charging the chassis battery from the solar panels.

Quote:

Originally Posted by Scalf77

Sorry to not explain myself correctly, I was interested in what the voltage was after you charged (minus surface charge). 0.2 amps is large load, doesn't sound right to me. You would be loosing 4.8 Amp-hrs per day, 33.6 Amp-hrs per week. What size is the starting battery? We are talking about a Winnebago Revel correct? They do show a solenoid in their electrical drawings, I expect that is what charges from the house battery when your driving. If you replace the solenoid with a ACR you would be able to charge from Solar & Shore if needed. What size alternator does the sprinter have?

I would really go to the RV dealer and have them explain why the load is so high. That is the real culprit, that is similar to the draw of my CO & LP detector. I suspect that your battery is not in good health if you have drained it multiple times. A hybrid starting AGM would only help, but would last longer. Installing a bidirectional ACR would allow you to charge from solar and shore, but still masking the real problem. You could also change momentary switch, to non-momentary and your existing solenoid could be forced to work.

greg

rean1mator · 03-15-2019, 09:54 AM

So I had Mercedes of Pleasanton do a diagnostics on my battery and they said that my battery tested as new. I had a lengthy conversation with the tech about the behavior I was seeing based on my tests and he says 12.4V is normal for the sprinter batteries.

He didn't give me a proper response on the fact that I was measuring under 12V after just 6 days however.

He also said the load measured on the chassis battery was 54 milliamps which is normal and seems normal to me. So I guess all is good? Although 12.4V seems way too low for a next day measurement after full charge if you ask me.

MBZ of Pleasanton is a great shop by the way. They didn't even charge me for the diagnostics which I know is normally charged if there is no warranty issue from the visit.

Scalf77 · 03-15-2019, 10:11 AM

So I would be thinking my isolator/separator is not working correctly, or they have wired something from the RV on the wrong side of isolator/separator. I am not sure how sprinter batteries go to 12.4 versus the rest of the 12 volt automotive world. If you could get a picture of the separator/isolator, they list three possible vendors. Maybe we can help going forward from there, sounds like this is not a one off problem.

-greg

Fitz · 03-16-2019, 10:14 PM

Quote:

Originally Posted by rean1mator

...the load measured on the chassis battery was 54 milliamps which is normal and seems normal to me.

FYI, this discussion got me curious so I got the clamp meter out and measured the parasitic drain on my 2016 - 50 milliamps

Edited/added the below information:

0.05x24= 1.2 Amps/Day. 1.2x7= 8.4 Amps/Week. My stock engine battery is a 95 AmpHour AGM, using the rule of thumb of never discharge below 50%, 95/2= 47.5 AmpHours available. 47.5/8.4= about 5 weeks for the battery to reach a state of charge (SOC) of 50%. Of course all this is assuming the battery starts out at 100% SOC, something that the alternator can’t really achieve. (Somebody help me on this, doesn’t the engine charging system top out at about 85% for an AGM battery?)

BTW, to answer Greg’s previous question, my Sprinter has a 220 Amp alternator.

rean1mator · 03-18-2019, 10:17 AM

Yeah, my battery(as well as other sprinter owners) draining down so quickly just does not make sense. guess i have some more troubleshooting to do.

Quote:

Originally Posted by Fitz

FYI, this discussion got me curious so I got the clamp meter out and measured the parasitic drain on my 2016 - 50 milliamps

Edited/added the below information:

0.05x24= 1.2 Amps/Day. 1.2x7= 8.4 Amps/Week. My stock engine battery is a 95 AmpHour AGM, using the rule of thumb of never discharge below 50%, 95/2= 47.5 AmpHours available. 47.5/8.4= about 5 weeks for the battery to reach a state of charge (SOC) of 50%. Of course all this is assuming the battery starts out at 100% SOC, something that the alternator can’t really achieve. (Somebody help me on this, doesn’t the engine charging system top out at about 85% for an AGM battery?)

BTW, to answer Greg’s previous question, my Sprinter has a 220 Amp alternator.

Backcountryguy · 04-15-2019, 07:55 AM

I'm having the same issue. It didn't manifest itself to us until I took a trip back east and the van was stored for 11 days, it's longest time sitting idle since we owned it (other than the long period at SMB West for its flarepod install).

See attached. Drone Mobile screenshot shows the start battery at 12.1 volts after less than 24 hours of sitting idle.

I took the van down to Momentum Vans in Arlington WA to discuss a few modifications/improvements. I proposed that we hook up a battery tender to the 110 side, with a permanent on/off rocker switch. I would use it only when the van is stored and hooked up to 110 volt shore power.

KenInRockwall · 11-09-2019, 01:59 PM

Anyone have a recommendation for a trickle charger for the Sprinter 2500? I had an official MB charger that worked for awhile, but it has apparently died. The MB charger can be left connected and it monitors the charge and supposedly does not over charge the battery. It is also expensive, so if it fails so quickly, it is not an economical solution. The solar chargers that I have looked into all have mixed reviews, leaving me wondering about the reliability of any of them. Also one cannot connect a charger via the cigarette lighter, it must be connected to the + and - terminals of the battery (those under the hood are ok).

jrobe · 11-10-2019, 08:00 AM

I own about 5 NOCO chargers. All my batteries are connected to them when not in use - Sprinter, boat batteries, lawnmower, ATV, etc. They work great and are much cheaper than new batteries.

Fitz · 11-10-2019, 08:53 AM

Quote:

Originally Posted by KenInRockwall

Anyone have a recommendation for a trickle charger for the Sprinter 2500? ……. Also one cannot connect a charger via the cigarette lighter, it must be connected to the + and - terminals of the battery (those under the hood are ok).

Post 617 (page 62) of my build thread shows a small CTEK charger plugged into the cigarette lighter of Flint. CTEK makes great products and this arrangement worked just fine until all the helpful members here convinced me to spend more money and upgrade from the Sure Power Separator to the Blue Sea ACR. (Great upgrade) That journey is chronicled from posts 617 through 645.

Here is the CTEK as I used it in this configuration. The cigarette lighter plug is a CTEK supplied option.