DiploStrat
Expedition Leader
Terrible write ups - I would go for Picker. That is the correct type of relay, however.
The starter is not an issue. Remember, the relay is normally closed, it opens when the engine is running.
AMP-L-START compatible with Battleborn lithium batteries?
- Thread starter jeegro
- Start date
Terrible write ups - I would go for Picker. That is the correct type of relay, however.
The starter is not an issue. Remember, the relay is normally closed, it opens when the engine is running.
I understand all that, what I don't get is how the battery monitor will count all the amps when all of the batteries are in parallel. Let's say I have 5 amps coming in from solar, enough to parallel link all the batteries, and I have 10 amps of house load. Who (which battery) is supplying that needed 5 amps? Isn't it possible that the 5 amps could come from the starter, flow across the house batt, be counted as negative 5 amps by the battery monitor, and go to the loads? So the SoC monitor thinks 5 amps came out, when in fact it could have only been 2 or 3 supplied by the house batt?
To satisfy my nerdiness, I was also thinking of putting in 3 cheap watt meters: https://www.amazon.com/bayite-6-5-1...ds=100a+shunt&qid=1556122161&s=gateway&sr=8-3
One on the BCDC negative ( to count charge)
One on the Load negative (to count loads)
one on the SBC negative ground (to see what's passing between banks)
As my SoC monitor will only tell me the net charge/discharge.
No, soon as loads are much higher than the solar input, the voltage drops below the Open setpoint.
Put another way, as long as the combiner is Open, the Starter is not getting depleted enough to worry.
But yes there are "diode" actually MOSFET based isolators out there, one-way like DCDCs, that don't drop voltage like the old-school ones. Not cheap though.
No, shunt placed properly should be counting all Ah, in both directions.
That isn't what I call a proper SoC gauge, just a simple AH totalizer aka coulomb counter.
Yes, my bad.
As long as all significant charge sources are hardwired to the House side, it really only takes a low-amp dumb cheap device to keep Starter topped up.
Echo Charger good example, little V drop.
Yes a "batt protect" unit could work too, even the little Samlex DIY UPS units, really a trivial issue.
Ambient temps need to stay below freezing a long time to penetrate to inside big prismatic cells.
And the alt needs protection from a BMS or LVC dumping the load, a $20 lead batt inline will do if not the Starter.
Personally, if space is limited, with pocket jumpstarters available for occasional belt-and-suspenders, I like getting away from "dead lead" dedicated Starter batts completely.
But the design deserves its own thread, this one's already scattered enough.
You must be joking!
Can't even.
Sorry that's such a level of penny foolish, I had assumed you wanted a robust setup with the other components cited.
Have a look at what the Close setpoint is for the Blue Sea ACRs, I think higher than resting LFP.
If so pick the ampacity you need, done.
The 500A rated ML version is bulletproof, will outlast a dozen trucks, pass it on to your grandkids.
Remote bypass switch for self-jumpstarting from House if needed.
If so pick the ampacity you need, done.
The 500A rated ML version is bulletproof, will outlast a dozen trucks, pass it on to your grandkids.
Remote bypass switch for self-jumpstarting from House if needed.
Cool. Got it. I have a proper SoC gauge (Blue sea 1830). Those cheap meters are just to breakdowns of the net charge/discharge that the SoC tells me.
The Xantrex Echo switches on at 13v, so no good for a lithium bank.
Haha, ok. This is pretty much what's available on Amazon/eBay. What's wrong with it? I only need to switch 25 amps max, and in reality it'll just be 1-5 amps.
I just pulled off and sold my ML-ACR, I think it's an overkill device for only maintaining the starter batt.
dwh
Tail-End Charlie
Whichever has the least resistance.
DiploStrat
Expedition Leader
As noted:
-- If you want a State of Charge meter (and you probably do) you need one that works with lithium. Thereafter, it is easy. The shunt is on the negative terminal of the battery(s) being measured. The meter ignores all other batteries - which is fine, you don't care about your starter battery as the truck will take care of it. So, if the camper battery charges the starter battery, it is just another load, like the refrigerator, etc. But, assuming that you set the voltages on your SBC correctly, this will only happen when the camper battery itself is under charge. Remember, that is why you spent all the change on the SBC.
-- The only reason not to use a TRK-L-CHARGE or the Sterling Battery Maintainer is that we fear that the voltage points are not correct. (I'm not totally convinced that this will be a problem in the real world, but I have not way to test.) But a Magnum SBC will do exactly what you want and you can use a relay to avoid any risk of a feedback loop.
To paraphrase Earthroamer, once you get this mess set up properly, you can forget it. It has been years since I have done anything but cast an eye at the hour count in the morning to see how far down I am (with an all electric camper it is typically 125Ah) and then a check a noon, to see how the recharge is coming, and finally a quick eyeball at 5PM to confirm that I am back at 100% before starting dinner, espresso, etc. I no longer have a stand alone SOC meter, I just use the option built into the Magnum inverter/charger. (My solar controller claims to measure SOC, but, as it lacks a shunt, it is just a voltage SWAG.
My Twisted Sister (tm) system is extreme overkill, mostly driven by the need to charge a 12v camper battery from a 24v truck and to maintain a 24v starter battery from a 12v camper battery. (Or, more precisely, from my 12v solar and shore chargers.) At the time REDARC approached me, I had not seen a voltage reducing B2B. As it turns out, Charlie Sterling has a B2B that takes in 24v and produces 12v and he also sells a battery maintainer that takes in 12v and produces 24v, so I could have done the same thing with Sterling.
-- If you want a State of Charge meter (and you probably do) you need one that works with lithium. Thereafter, it is easy. The shunt is on the negative terminal of the battery(s) being measured. The meter ignores all other batteries - which is fine, you don't care about your starter battery as the truck will take care of it. So, if the camper battery charges the starter battery, it is just another load, like the refrigerator, etc. But, assuming that you set the voltages on your SBC correctly, this will only happen when the camper battery itself is under charge. Remember, that is why you spent all the change on the SBC.
-- The only reason not to use a TRK-L-CHARGE or the Sterling Battery Maintainer is that we fear that the voltage points are not correct. (I'm not totally convinced that this will be a problem in the real world, but I have not way to test.) But a Magnum SBC will do exactly what you want and you can use a relay to avoid any risk of a feedback loop.
To paraphrase Earthroamer, once you get this mess set up properly, you can forget it. It has been years since I have done anything but cast an eye at the hour count in the morning to see how far down I am (with an all electric camper it is typically 125Ah) and then a check a noon, to see how the recharge is coming, and finally a quick eyeball at 5PM to confirm that I am back at 100% before starting dinner, espresso, etc. I no longer have a stand alone SOC meter, I just use the option built into the Magnum inverter/charger. (My solar controller claims to measure SOC, but, as it lacks a shunt, it is just a voltage SWAG.
My Twisted Sister (tm) system is extreme overkill, mostly driven by the need to charge a 12v camper battery from a 24v truck and to maintain a 24v starter battery from a 12v camper battery. (Or, more precisely, from my 12v solar and shore chargers.) At the time REDARC approached me, I had not seen a voltage reducing B2B. As it turns out, Charlie Sterling has a B2B that takes in 24v and produces 12v and he also sells a battery maintainer that takes in 12v and produces 24v, so I could have done the same thing with Sterling.
Having an ML already in place that will last forever, and pulling it out because it will standup to higher amps than you currently use?
Setpoint already going to work too, so really?
And yes side discussions do not necessarily apply to the specifics of the OP.
Looking for good relays at a reasonable price myself, lots of junk out there, definitely avoid consumer-level junk though, Digi, Mouser, element14 are all trustworthy.
Setpoint already going to work too, so really?
And yes side discussions do not necessarily apply to the specifics of the OP.
Looking for good relays at a reasonable price myself, lots of junk out there, definitely avoid consumer-level junk though, Digi, Mouser, element14 are all trustworthy.
My reco coulomb counter for precise bank SoC is Victron BMV-712. Anything without input variables for Peukert coefficient and CEF is for just showing V, A and counting Ah.
Must reset frequently for 100% based off endAmps.
Newer unit may eliminate lots of such pain points is Balmar SG200.
Old Merlin SmartGauge is still the most accurate SoC and user friendly, but lead only.
Must reset frequently for 100% based off endAmps.
Newer unit may eliminate lots of such pain points is Balmar SG200.
Old Merlin SmartGauge is still the most accurate SoC and user friendly, but lead only.
Have you re-routed alt output to House?
Curious what did you get for the ML? Rarely seen at much discount even used
DiploStrat
Expedition Leader
FWIW: BlueSea ACR: Combine - 13v, Separate - 12.75v