Trik-L-Start with Sterling charger

treemaze

2020 Unity MB
After reading about all the Trik/Amp-L-Start installs on this forum, I wanted to use one in my 2020 Unity MB to keep the chassis battery charged, since it sits idle for months at a time. For 2020 Unity models, LTV started using the Sterling DC/DC charger to charge the house batteries. It interferes with the Amp-L-Start charger, which is used to charge the chassis battery. There’s a thread with more info here, but the basic problem is that both the Sterling and Amp-L-Start want to run at the same time, making an infinite loop of current.

I’m going to try manually disconnecting both the chassis and house batteries from the Amp-L-Start with a switch and relay. When the RV is being used there’s no reason to use the Amp-L-Start, assuming it’s not parked for weeks in one spot. In fact, I found that the Amp-L-Start can draw significant current while I’m trying to charge the house batteries via solar panels, even if I drive every day, unnecessarily reducing amp-hours going into the house batteries. I added the on/off switch to the side of the passenger seat where there were already 3 switches for the awning.

Switches.jpg

The other parts of the circuit are located under the passenger seat, except for a wire I ran directly to the chassis battery (schematic attached). There are channels for wiring between passenger and driver seats, and then from the driver seat into the battery compartment.

There are still things I don’t like, such as when the Sterling turns on briefly every few minutes when the Amp-L-Start is charging (I thought the Sterling turned on only when the ignition is on). Since I’ll use Amp-L-Start only when parked for a long time, usually plugged into shore power, this probably isn’t a big deal.

If anyone has used the Amp-L-Start with a Sterling charger, how did you make it work?
 

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SSTraveler

2014 LTV Unity Murphy Bed
It sounds like your solution to add a switch maybe the best method to deal with this conflict. Putting an Isolator Solenoid between the two battery banks and before the Sterling may also be a solution. This thread mentions that the Sterling with the V69 software can be put into "ignition only mode" which could solve the problem as well, https://sprinter-source.com/forums/index.php?threads/81235/page-2. Please share any results you find as you seek to resolve this trickle charging conflict.

Given this potential conflict between dc to dc chargers and trickle charging options for the Chassis battery, owners doing their own Lithium battery and solar upgrades may want to consider the Renogy DCC50S 12V 50A DC-DC ON-BOARD BATTERY CHARGER WITH MPPT, https://www.renogy.com/dcc50s-12v-50a-dc-dc-on-board-battery-charger-with-mppt/. This new Renogy product maybe a great option to get a 50a dc to dc charger for the Lithium house batteries and a dedicated MPPT solar controller (add a 20w-50w solar panel) for profile specific charging for the AGM chassis battery. I have AGM house and Chassis batteries and my Victron MPPT solar controller says it only needs about 4w of solar each day to keep my three batteries charged up while in storage. So pairing the Renogy DCC50S with a 20w-50w solar panel is more than adequate to maintain the single AGM chassis battery.
 
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treemaze

2020 Unity MB
Rexabbot and SSTraveler, that's good advice. I assumed my Sterling was too old for V69 software, but it's not, so I turned on its pure ignition mode (I think -- there's nothing I can find to indicate it's on, and I emailed Sterling for clarification). I experimented a little and the Sterling came on only when the engine was running, whether the Amp-L-Start was charging or not. Good so far, but given how inconsistent it's been in the past it will take some time to verify. A new DC/DC charger may be a better solution and 50A is about right, since the fridge takes so much of the Sterling's 30A.

I think it's still valuable to have a switch on the Amp-L-Start because it draws too much current when I'm boondocking with solar power. I'm guessing this is because of the smart alternators that don't fully charge the chassis battery, so the Amp-L-Start is trying to fully charge it. It may be even better to just remove the Amp-L-Start. I'll be adding a Victron MultiPlus that can trickle charge the chassis battery when on shore power and that seems a lot less complicated.
 

treemaze

2020 Unity MB
To follow up on using the Sterling's pure ignition mode to enable charging house batteries only when the engine's running: I can't get it to work. It still turns on sometimes when the Amp-L-Start is charging the Sprinter's battery, even though the ignition wire to the Sterling is 0 V. The Sterling tech support was quite helpful going over some options and said it should not be charging in that mode when the ignition signal is low.

I'm just going to leave it like this though since adding the switch to the Amp-L-Start solves the problem of it turning on whenever the Sterling turned on. Starting over, I would not mix Amp-L-Start and Sterling.
 

SSTraveler

2014 LTV Unity Murphy Bed
Something lvuman and I discovered about the Renogy DCC50s, when you use the dual charging inputs of both DC-DC charger and solar. Renogy limits the output of each source to 25a. We didn't pick this up when we read the manual before he installed it. It's ridiculous that Renogy would design it this way since the DC-DC charger is fully capable of putting out 50a charging from the alternator. Ivuman discovered the work around is to just turnoff using a switch (many just replace the GoPower controller with a switch) or flip the circuit breaker on the Positive wire of the solar panel feed to the Renogy for when you are driving to get the maximum 50a Alternator charging. Then just flip the solar panels back on to the Renogy when parked at a campground or in storage. We still believe the Renogy DCC50s is a great option to get both alternator charging and a chassis battery maintainer (from mixed chemistry battery systems). But I wanted to let you know what we discovered about it.

20201209_054656.jpg
 

Rexabbot

Member
To follow up on using the Sterling's pure ignition mode to enable charging house batteries only when the engine's running: I can't get it to work. It still turns on sometimes when the Amp-L-Start is charging the Sprinter's battery, even though the ignition wire to the Sterling is 0 V. The Sterling tech support was quite helpful going over some options and said it should not be charging in that mode when the ignition signal is low.

I'm just going to leave it like this though since adding the switch to the Amp-L-Start solves the problem of it turning on whenever the Sterling turned on. Starting over, I would not mix Amp-L-Start and Sterling.
what can we do instead? Just disconnect the chassis battery?
 

treemaze

2020 Unity MB
what can we do instead? Just disconnect the chassis battery?
Maybe, depending on your situation. Supposedly the chassis battery is fine for a couple months if it's disconnected.

That wasn't my problem though. I wanted the Amp-L-Start to stay turned off while I was camping, since then there's no reason to worry about charging the chassis battery. But it turned on all the time, as it's designed to, whenever there's a charging source on the house batteries (solar, alternator, generator, or shore power). So I'm happy with my circuit that disconnects Amp-L-Start from both batteries. With Amp-L-Start disabled, it doesn't "steal" power from the Sterling charger or the solar panels when you really want that power going to the house batteries. Once I get home, I can turn on Amp-L-Start again to keep the chassis battery charged.
 

SSTraveler

2014 LTV Unity Murphy Bed
After looking into this more, what appears to be the issue is that the Sterling's default settings keep it looking for a Battery In (chassis battery cable) voltage to wake it up, even when the ignition is off and you have it wired for Mode 2. What happens is you switch the Mercedes off and walk away, but when the Trik-L-Start senses the chassis battery needs charged it sends over 13.2v from the house battery charging to the Battery In - chassis battery cable, which makes the Sterling come on and tries to start charging the house batteries from the chassis battery thinking the ignition has been switched on.

So you need to follow the procedure on page 7 to put your Sterling unit (with new V69 software) in Pure Ignition Mode, this way when the ignition is off the Sterling is off and won't come on and try to start working when the Trik-L-Start sends a voltage greater than 13.2v to the Battery In Chassis battery cable. It is a ridiculous process to reset the Sterling to the Pure Ignition Mode and there isn't any indication to let you know you were successful. If I wouldn't have gotten my Sterling BB1230 from EnerGT I probably would select another brand of DC-DC charger. So use a stopwatch on your phone to ensure your pressing it for the 40+ seconds and hope it takes to get it to pure ignition mode. Putting it in Pure Ignition Mode should resolve the conflict. I'm going to be installing a Sterling and a Trik-L-Start in my upgrade so I'll report more as I learn.
Screenshot_20210105-054837_Adobe Acrobat.jpg
 

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hoosierrun

Active member
Basically, that is the way my waterproof Sterling works (model BBW1260). If you connect the blue wire that went to the old IRD which is the ignition feed (12 volts on wire when ignition switch is on), the Sterling will never come on until the ignition switch is turned on. That basically shuts off the Sterling when the ignition key is removed from the vehicle. There is no chance the Sterling will come on not matter how much the starter battery rises.
 

SSTraveler

2014 LTV Unity Murphy Bed
Are you saying you didn't have to reset your Sterling to the Pure Ignition Mode? If so the the blue wire off the old IRD must be a different Ignition signal because it seems that the 2020 folks are having the issue. Leisure's actually has 2 small orange wires going into the Ignition wire location on the Sterling. My 2014 has the IRD so I'll try it as you say yours is connected first and see if I have the issue and then try changing the settings to Pure Ignition Mode if I do. I have to add 50a circuit breakers to both sides of my Sterling installation because there are no fuses or breakers in the Leisure wiring of the isolator solenoid and Sterling recommends 50a circuit breaker/fuse on both sides of the battery connections. Worst case I can use the circuit breaker to disconnect the Sterling from the chassis battery when parked in storage.
 

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hoosierrun

Active member
Not sure about the 2020 (or newer generation) Sprinters. My 2016, 3.0, does not use the pure ignition mode (i.e., no regenerative braking). I have a couple of orange wires that originally connected on the house side of the old IRD relay contactor. Those were simply the wires for the stabilizers and the Kwikee entrance step. They are direct connect to the house battery and do not go through the main battery switch for safety reasons. I simply moved those orange wires over to the house side battery terminals on my Sterling. One of the reasons I like the BBW1260 version is that it has studs for the battery connections. Therefore, I simply took the battery cables from the isolator relay (ring lugs) and moved them to my Sterling. It was super easy and the cables reached. Then on my BBW, there is a terminal block that I connected the blue wire to. Setup for the profile is done by magnetic swipe. It can be intimidating to some people (I used similar equipment in my industry), but I read the instructions 3 or 4 times and got it right my first try. You get confirmation via lights on the unit. It is a good idea to add fuses or circuit breakers on the battery input and output. Perhaps ANL fuses with studs to accommodate ring lugs (provides least trouble). A new ground wire will need to be run to power the Sterling (i.e. a return for its internal power needs). On the BBW, you get a long fused pigtail that is your ground.

I think I am the only one using the BBW1260 at this time (it is a newer product). So far my results are satisfactory and I am pleased, especially with the simplicity of installation. It think the price is the same. I just got mine off Amazon when Sterling came out with the unit about 1-1/2 years ago.

Keep in mind that my LTV is a Serenity which is functionally wired the same as a Unity, but with equipment installed in different locations.
 

DavidY

2020 Unity MB
First off, thank you for all the wonderful information provided on this forum. What a great resource. I have a 2020 Unity MB and attempted to put in the Trik-L-Start. Followed all the procedures previously mentioned (connected to the Sterling, put the Sterling into ignition mode), but the Sterling still comes on with the ignition off. The lights are on and the fan cycles on and off. Any ideas? Thanks
 

treemaze

2020 Unity MB
I chose to isolate the Trik-L-Start instead of the Sterling. When driving you want the Sterling on and Trik-L-Start off.

Be careful how you connect the Trik-L-Start's starter battery wire. SSTraveler's diagram shows it connecting to the cable that goes to the Sterling's input. In my 2020 Unity the Sterling's input is usually 0V when the ignition is off, so I assumed it was disconnected from the battery. I added a new wire from the Trik-L-Start to the starter battery.

It's OK to connect the Trik-L-Start's house battery wire to the Sterling's house battery cable.
 
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SSTraveler

2014 LTV Unity Murphy Bed
I'm in the process of installing my Sterling and I have 50a circuit breakers on either side of it with my Trik-L-Start connections on the battery connection side of the circuit breaker. Then the Sterling will be connected to the opposite terminal so if I find I have this issue I can just disconnect the Sterling Battery In connection and that should solve the problem I will then just use the Battery In circuit to manage whether I want the Sterling or the Trik-L-Start functions. I may also add switches to the Trik-L-Start yellow and blue wires but that will be a last resort. My chassis battery wire is always hot so I don't have the same wiring as the newer Leisure on the chassis battery side.
 

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hoosierrun

Active member
I chose to isolate the Trik-L-Start instead of the Sterling. When driving you want the Sterling on and Trik-L-Start off.

Be careful how you connect the Trik-L-Start's starter battery wire. SSTraveler's diagram shows it connecting to the cable that goes to the Sterling's input. In my 2020 Unity the Sterling's input is usually 0V when the ignition is off, so I assumed it was disconnected from the battery. I added a new wire from the Trik-L-Start to the starter battery.

It's OK to connect the Trik-L-Start's house battery wire to the Sterling's house battery cable.
So it sounds like there must be a relay contactor in-line between the Sterling input and the MB starter battery. That is good info to know. If that is indeed how it is wired on your 2020, then getting on the battery side of that contactor or on the actual starter battery would be required or you will never trickle charge the starter battery. Thanks for pointing that out!
 

msmolow

2019 Unity CB / 2018 Chas
I emailed the Amp-L-Start manufacturer the following but after two days have not yet received an answer. Maybe the brain trust here will know. Unlike what is shown in treemaze's schematic, I will branch off the wire from the alternator to the Amp-L-Start before that wire reaches the dc-dc charger.

Here is my crude drawing. Circuit protection is not shown. The dc-dc charger also goes to the buss not directly to the fuse as shown.

2amp l start.jpg

This is the email I sent without the drawing:

I will soon have lithium house batteries with the following charging sources:

Shore and generator thru a Victron Multiplus 3000.

Solar thru a Victron MPPT charge controller.

Mercedes alternator thru a Victron Smart dc-dc charger.

My question:

If I wire the AMP-L-START in parallel with the Smart dc-dc charger, when the alternator is running will current flow from the alternator thru the AMP-L-START to the coach batteries bypassing the Smart dc-dc charger with it’s lithium 3 stage charging profile? That would be bad. Put another way, does the AMP-L-START allow only one way flow, only from the coach battery to the starter battery and NOT from the starter battery to the house batteries?
 
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treemaze

2020 Unity MB
It appears current can sometimes flow from starter to house battery, according to this email from April 2020.

My inquiry to LSL Products:
I recently installed Amp-L-Start in my RV between house and starting
batteries. The starting battery was a bit discharged and appeared to
charge correctly, with the yellow LED illuminated and after about 30
minutes switched to the green LED. Today I removed the house
batteries, and the Amp-L-Start green LED stayed lit and the red house
LED was not lit. Also the RV lighting continued to work with no house
batteries connected. The Amp-L-Start appears to be drawing power from
the starting battery and sending it to the house. The house terminal
on the Amp-L-Start shows 13.0V (same as starting terminal voltage)
even with no wires connected to the house terminal.

Should the Amp-L-Start ever send power from the starting battery to
the house terminal? This is not what I expected to happen.

Joel Donaldson (from LSL Products) Reply:
AMP-L-START only checks for the presence of house batteries when their
voltage drops below the cut-off point (12.8 volts for "Normal" mode).
Until this happens, both battery banks are connected together, and thus
AMP-L-START has no way of knowing which battery is supplying voltage to
it - and thus no way of knowing if a battery is now disconnected.

Typically, cut-off happens a few minutes either after your house battery
charger is no longer supplying a charge, or when the voltage on the
starting battery drops below the 12.8 volt cutoff point.

Note that if you remove your house batteries but still leave your house
battery charger turned on, cutoff will never be reached, since your
house battery charger will continue to maintain the voltage above the
cutoff point.
 

hoosierrun

Active member
You would think there would be a diode in the circuit to prevent any reverse flow... plus if you have lithium batteries, they should be at a higher voltage than the starter battery preventing any reverse flow. In the case where you disconnected your house batteries, I would only expect power going into the house side wiring through the charging device when the vehicle is running (thus allowing your lights to come on), OR if there is still any solar contribution, the house side wiring would get some power unless you removed the solar fuse.
As a test, with your house batteries disconnected, you could lift one of the AMP-L-START leads and see if your RV house lights go out. That would almost certainly provide the confirmation that power can go in reverse through the AMP-L-START device... or not
 
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