Trik-L-Start with Sterling charger

treemaze

2020 Unity MB
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 you 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
All good points -- I wish I had disconnected the starter battery from the Amp-L-Start to see if the house lights went out. I cannot see what else could have powered them, since the Unity was parked in my garage (no solar or alternator) and not plugged in. Besides, Joel admitted "both battery banks are connected together". A diode in the path would block reverse current but there'd be some voltage drop too. If that's OK maybe one could be added in series with the Amp-L-Start.

I don't see why msmolow's schematic wouldn't work. But keep in mind that the Amp-L-Start is another load on all the charging devices, and could in theory consume a big part of the Victron DC/DC converter's output. If the starter battery voltage is high enough that wouldn't happen. I'm guessing it could be more of a problem with smart alternators where their voltage can be all over the place.
 

msmolow

2019 Unity CB / 2018 Chas
But keep in mind that the Amp-L-Start is another load on all the charging devices, and could in theory consume a big part of the Victron DC/DC converter's output. If the starter battery voltage is high enough that wouldn't happen. I'm guessing it could be more of a problem with smart alternators where their voltage can be all over the place.
The dc-dc charger is only producing amps when the engine/alternator is running. In that event the alternator is charging the starter battery and most likely topping it off with plenty of excess to keep the 30 amp dc-dc charger sending to the house battery. Do I have that wrong, or will I be in a loop until the starter battery charges?
 
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hoosierrun

Active member
The dc-dc charger is only producing amps when the engine/alternator is running. In that event the alternator is charging the starter battery and most likely topping it off with plenty of excess to keep the 30 amp dc-dc charger sending to the house battery. Do I have that wrong?
Sounds right. Another way to look at it is the DC to DC charger is drawing off the starter battery as long as the starter battery remains above 13.3 and the vehicle running sense line (blue wire) is hot at your converter. Since the alternator is connected to the starter battery, and the input to the DC to DC converter is connected to the starter battery, the voltages are all the same. The alternator is always reading that voltage at the starter battery positive post to regulate the current. As the DC to DC converter draws the starter battery to lower voltage, the alternator increases its output voltage to push more current into the system. As long as the vehicle is running and the alternator is turning (and the alternator internal regulator is working), the starter battery is healthy (above 13.3 volts), the system should be working properly. Note that the Sterling does its own regulation which is dictated by the battery chemistry profile and house battery state-of-charge, so it will not accept more current than needed.
 

autostaretx

Erratic Member
You would think there would be a diode in the circuit to prevent any reverse flow...
...
That would almost certainly provide the confirmation that power can go in reverse through the AMP-L-START device... or not
Most of the voltage-sensing charging devices (such as the BlueSea ACRs) state (somewhere, perhaps in tiny print) whether they're one-way or bi-directional. (BlueSea sells both flavors).

Many people like the idea of having Solar charge one side, and shore power charge the other, letting the device share whatever wealth that appears.

For some it's a bug, for some it's a feature.

--dick
 

msmolow

2019 Unity CB / 2018 Chas
Has anyone used a circuit breaker(s) wit the Amp-L-Charge? The instructions/wire diagram does not show any.
 

msmolow

2019 Unity CB / 2018 Chas
I received this reply from Amp-L-Start. It's an interesting solution.
---------------------

In applications where charging sources other than the alternator are supplying power to the house batteries while the motorhome is under way, the simplest solution is to connect AMP-L-START's GND. [-] terminal to the motorhome's Ignition [+] wire.

Here's a link that illustrates these modified connections:

http://www.lslproducts.net/ALS_Disable_Diagram.jpg

Basically, whenever the ignition switch is on, it supplies the GND. [-] terminal with roughly the same voltage as is present on the HOUSE [+] and STARTING [+] terminals, effectively shutting off power to the AMP-L-START.

With no power being supplied to the AMP-L-START, it doesn't pass current in either direction - and is effectively bypassed. Naturally, while in this state, it draws no current.

When the ignition switch is off (i.e., your motorhome is parked), it drops down to zero volts, allowing the AMP-L-START to operate normally.

The advantage of this approach is that it's simple - No additional relays required.

Note that since AMP-L-START's GND. [-] terminal carries almost no current, it doesn't require the same thick-gauge wire required for the HOUSE [+] and STARTING [+] terminals.

For comparison purposes, you can download a copy of the AMP-L-START instructions at this link, which shows the "standard" connections (i.e., GND. [-] terminal connected to chassis ground, instead of to the Ignition [+] wire):

http://www.lslproducts.net/ALS_Instructs.pdf
 

autostaretx

Erratic Member
Umm
I received this reply from Amp-L-Start. It's an interesting solution.
---------------------

In applications where charging sources other than the alternator are supplying power to the house batteries while the motorhome is under way, the simplest solution is to connect AMP-L-START's GND. [-] terminal to the motorhome's Ignition [+] wire.
....
Basically, whenever the ignition switch is on, it supplies the GND. [-] terminal with roughly the same voltage as is present on the HOUSE [+] and STARTING [+] terminals, effectively shutting off power to the AMP-L-START.

With no power being supplied to the AMP-L-START, it doesn't pass current in either direction - and is effectively bypassed. Naturally, while in this state, it draws no current.

When the ignition switch is off (i.e., your motorhome is parked), it drops down to zero volts, allowing the AMP-L-START to operate normally.
Unfortunately, that won't work if you simply use the MB's EK1 "ignition on" (or D+) terminal.
(perhaps depending upon the model (T1N: maybe, NCV3 and VS30: nope)) all models.

On the T1N, NCV3 and VS30, the Ek1 terminals are fed by the "normally open" contacts of a relay.
When they're "off", they simply "float" ... they're not explicitly brought anywhere near "ground".
If you *also* had some other load on that circuit (such as an incandescent light bulb, not an LED), then it would work (the Trik-L's need for a ground would happily pass through the light bulb to ground).

2007 (NCV3):
1610829686457.png
That drawing shows that *if* you have MB's isolator relay, *its* coil is driven "further up the chain", so using its coil connections *would* serve for the Trik-L-Start's "ground" trick. Leave the wires connected to the coil, and tap off for the Trick-L.

T1N:
1610830060108.png

On the T1N, you can also chase the wires back up the chain to locate wires you could tap into.

--dick
 
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SSTraveler

2014 LTV Unity Murphy Bed
My Trik-L-Start wouldn't work when I tried to use the white wire ground connection of the Isolator Solenoid. It would only work when I moved it's ground to the metal seat base box.
20210117_083209.jpg
 
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autostaretx

Erratic Member
That's not an MB-installed isolation relay, so bets are even further off...

I believe what you have listed as "isolator relay" (with the three thin wires) is really a time-delay relay.
Instead of using the Sprinter's D+ (alternator running) signal, they simply watch the "ignition on", but hold off on actuating the "isolator solenoid" for some number of minutes (5? 15?).

--dick
 

hoosierrun

Active member
That's not an MB-installed isolation relay, so bets are even further off...

I believe what you have listed as "isolator relay" (with the three thin wires) is really a time-delay relay.
Instead of using the Sprinter's D+ (alternator running) signal, they simply watch the "ignition on", but hold off on actuating the "isolator solenoid" for some number of minutes (5? 15?).

--dick
The black box is really just control electronics for the solenoid coil. It incorporates a wait time (I'm guessing a minute or two) and it requires the charging voltage (measured at the starter battery) to be above a certain voltage for so long (I think 13.5 or 13.8). when the conditions are met, it applies voltage to the solenoid coil so that it closes in and connects the 2 batteries together. If, for some reason, the starter battery drops below a threshold voltage (possibly 13.2), the control box (called IRD) opens the voltage to the solenoid coil, opening the contacts and allowing the starter battery to continue to charge at what ever the (regulated) alternator can deliver. Exact voltages and delay times for those operations can be found in the manual and the manual can easily be found by searching for Itellitec model 000-00629-120.
 

msmolow

2019 Unity CB / 2018 Chas
I've been wrestling with how to incorporate an Amp-L-Start using a relay but came to the conclusion a manual switch to disconnect it while driving would be easier and suit my purposes just fine. I then went online and read SSTraveler's excellent summary of the issues in post #34 here https://sprinter-source.com/forums/index.php?threads/93929/page-2
It validated my solution to see she also decided on a manual switch.
I have a Victron Smart dc-dc charger (12/12-30). The stock setup uses an internal algorithm to determine engine is running detection as described in the attachment. There is an option to wire in D+ as an engine detection override.
If the Amp-L-Start confuses the dc-dc charger as to whether the engine is running I will have the ability to manually disable the dc-dc charger through the Victron Connect app when I am at a campsite or the storage lot.
 

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treemaze

2020 Unity MB
I used a relay only because I couldn't find an appropriate DPST switch to fit on the side of the passenger seat. When I tried to disable the Amp-L-Start by disconnecting only the starter battery, it would beep sometimes and not stop until I connected the battery again. It seemed random and I couldn't figure out why, but I knew if I disconnected both batteries from the Amp-L-Start that it couldn't beep, so that's how I disable it now.
 
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msmolow

2019 Unity CB / 2018 Chas
When I tried to disable the Amp-L-Start by disconnecting only the starter battery, it would beep sometimes and not stop until I connected the battery again. It seemed random and I couldn't figure out why, but I knew if I disconnected both batteries from the Amp-L-Start that it couldn't beep, so that's how I disable it now.
Thank you. That will save me much frustration, as will this entire thread which I just re-read. Note to self, do that more often.
 
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SSTraveler

2014 LTV Unity Murphy Bed
You are confirming that there is really no elegant chassis battery charging solution from a Lithium house bank. I have to park/store my Leisure in our Developments RV storage area so I want an automatic, can be left for up to 6 months, system for maintaining my AGM chassis battery from the Lithium house battery Solar charging. There are several trickle chargers on the market (Amp-L-Start/Trik-L-Start/Xantrex ECHO) that normally attach across an Isolator Solenoid but these seem to cause DC-DC chargers that are used as replacements for the Isolator solenoid to get confused as to whether the Alternator is running or not. I used to use a Trik-L-Start with my Isolator Solenoid and it worked perfectly for my needs. I personally like the Trik-l-start, because it just cycles on and off to trickle charge the chassis battery, which is a good method when using a Lithium house bank, which has a distinctly different charge profile. Since a Lithium bank float charges at less than 13.5v this is a perfect voltage for the Trik-L-Start to take sips from to maintain the chassis battery. The other thing I like about the Trik-L-Start, is that it uses a voltage of about 0.3v less (based on Trik-l-start documentation and my experience using one) than the house bank to charge the chassis battery too. So that means it's basically floating the chassis battery at 13.2v which is perfect for an AGM battery. A Trik-L-Start is very easy to attach in conjunction with a DC-DC charger in a similar fashion to the old Isolator Solenoid. The worst case scenario I see is that I may have to install a switch on the house battery wire of the Trik-L-Start. Then when using my Leisure, driving, I use this switch to disconnect the Trik-L-Start from the house batteries and when parked/storage I flip the switch to turn on the Trik-L-Start on. If I find the Sterling coming on when the Trik-L-Start charging voltage is sensed by the Battery In (chassis battery cable) cable then I will simply flip the chassis battery cable circuit breaker to disconnect the Sterling from any incoming voltage that it would sense when the Trik-L-Start sends charging voltage to the chassis battery. That’s pretty straight forward, I can live with this procedure. I'm in the process of installing my Sterling and Trik-L-Start so I'll report back on what I finally figure out about how this setup ends up working.
 

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treemaze

2020 Unity MB
The Amp-L-Start has a jumper to use for lithium batteries that increases its turn-on/turn-off voltages slightly. I didn't use the jumper, so the Amp-L-Start behaves more like a Trik-L-Start and will usually charge the chassis battery even when the lithium house battery isn't charging. This works for me because I don't leave the house batteries on a charger but still want to charge the chassis battery sometimes.

So I think SSTraveler's setup will work fine with the Trik-L-Start.
 

DavidY

2020 Unity MB
I have the 2020 Unity MB with the Sterling 1230 already installed. Since both positive wires are already fused, could I isolate the Sterling by putting a switch (50 amp) on the negative wire to isolate it when I want to use the Trik=L-Start? Thankls
 

SSTraveler

2014 LTV Unity Murphy Bed
I used a 50a circuit breaker which you can also use as a switch. I added a switch to the Trik-L-Start yellow wire as well just in case I wanted to isolate it from sensing the house charging. Here is the wiring diagram I used. I actually added a 50a circuit breaker on both sides of the Sterling, which is what they recommend. Leisure uses 80a fuses on the house and chassis battery wiring of the 2020 and newer models, which mine didn't have.

20210118_064345.jpg
 

harrysalit

2019 Wonder FTB
LSL Products recommends the AMP L START. For lithium batteries, but on this post Trikl & Ampl are mentioned and used. I know there is a Amp differences but any other reason to use one over the other?
 

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