Travato LiFePO4 Battery Install - Page 7

booster · 08-19-2015, 12:39 AM

I think I have figured out what they probably do on the Travato alternator to coach feed.

The 50 amp breaker is after the disconnect that feeds the coach, so that is what it is for-nothing to do with charging.

The 1 ga wire is that size because the power comes off of the power distribution block fuse that is mounted on top of the engine starting battery, best conjecture.

Here is a pic that shows the block with wire added for an extra battery, not Travato. It is connected to a large fuse and I bet Winnebago did the same. I couldn't find the fuse size, but it is probably about the same as the alternator output.

markopolo · 08-19-2015, 12:41 AM

This should be it: http://www.winnebagoind.com/diagram/...ire_189041.pdf

This one - http://www.winnebagoind.com/diagram/...ire_190502.pdf - from the 59K (I think) is a bit clearer.

There might not be a fuse or breaker on that line. That's what was indicated to me but I'm not 100% sure about how it is wired.

wincrasher · 08-19-2015, 01:04 AM

I'll have to pop the cover on my coach battery to see if it has the same leads. My recollection from being in there before is that it is the same.

I had also looked at the drawings Marko linked. Was thinking the 50 amp circuit breaker would be the governing factor. You may be right though, there may be nothing else.

booster · 08-19-2015, 01:20 AM

Hard to tell without a close look, but the wire to your coach may hook up to the other side of the fuse, depending on which side the alternator feed goes into the box.

From all this, it does look like you have no isolator or separator, so you can kill all the batteries by leaving something on in the coach?

wincrasher · 08-19-2015, 01:38 AM

There must be some separation. There is the "boost" switch on the dash so you can combine the house and coach batteries to start the engine.

Also, I put a trickle charger on the chassis battery. The higher voltage does not read on the house side on my meter.

Another twist - Winnebago told one owner that called that the house battery will be charged by the alternator even if the main disconnect switch is engaged. That seems odd to me, but I haven't tested if that is true.

booster · 08-19-2015, 01:45 AM

Quote:

Originally Posted by wincrasher

There must be some separation. There is the "boost" switch on the dash so you can combine the house and coach batteries to start the engine.

Also, I put a trickle charger on the chassis battery. The higher voltage does not read on the house side on my meter.

Another twist - Winnebago told one owner that called that the house battery will be charged by the alternator even if the main disconnect switch is engaged. That seems odd to me, but I haven't tested if that is true.

There was a plain, large, relay shown in the parts diagram mounted in the rear area by the 12v coach disconnect and the 50 amp breaker. I will bet they must activate that off the run circuit of the engine to connect the batteries, and it also could be run by the boost switch. Makes sense.

If you mean the coach 12v disconnect switch as the main switch, then it is very common for the batteries to charge with it off, as it is after the connection of the batteries to each other.

ptourin · 08-19-2015, 04:23 AM

I'd love to know what StarkPower means in that ad. A PD Support guy told me that there's no communication between the PD9100L series chargers and the batteries/BMS's, and that once the battery gets near full charge and the charger goes up to 14.6v, the charger current simply drops until at full charge the battery is held to 14.6 and the current goes to zero. That seems in line with StarkPower's statement at the top: " "Smart" chargers stop charging once 14.6V is reached. "

The statement at the bottom is less clear: "Can be left on StarkPower battery and will restart with low voltage signal from battery." That sounds like some sort of BMS->charger communication, which the PD guy says doesn't happen.

Wincrasher, your experience with the charger is similar to mine - I have a 60A charger, and the most I've seen it put out (measured at the monitor - I haven't measured it with a clamp meter since I did the install, but when I did, the current at the charger was just a bit higher than what the monitor read) is about 45A, about 3/4 of it's rated output. That's like what PD said to you - expect around 35A max from your 45A charger. I'll know more about this the first time I start charging when the batteries are further down - wondering if I'll see higher charger current then.

I haven't checked too much on alternator charging current to the batteries - I'm usually the one driving so I can't check - but the few times I looked, I saw around 40A. I assume that if the Sprinter battery load is low, there's more available to charge the house batteries, and if I have all the lights on, etc., there's less available - but haven't had time to play with it yet. At any rate, it was good to see that the batteries went up to around 14.1-14.2v while driving - and that I was approaching full charge from the alternator.

booster · 08-19-2015, 03:54 PM

It might pay to give Stark a call, but the PD literature would indicate what they are saying is either totally wrong, or at least deceiving.

The 9140L, at least in the literature that I found, is a 14.6v power supply that says it tapers the current as the battery fills. Pretty much all chargers do that. It says it does it by sensing the battery voltage, but it can't really do that unless it is running wide open and not reaching it's setpoint of 14.6v, so that doesn't make sense. It says nothing about it shutting off and restarting.

What Stark is implying is a straightforward CC/CW charge profile with full shutoff and voltage monitoring to a restart voltage point. Magnum and others use this profile, and it would be very good for lithium, so maybe Stark is trying to capitalize on that. Unfortunately, the PD doesn't look like works that way.

ptourin · 08-21-2015, 05:35 PM

Here's a quick observation about alternator behavior. When the battery was down to 50% and we started driving, I got back up to 100% in about 2-1/2 hours. Earlier I saw around 40A from the alternator, so this makes sense - I think the voltage reading was around 14.1-14.2. Now we've been driving for some time, and the only load is the fridge on 12vdc. Voltage is sitting at 14.05 and when I watch the monitor sample the current, I usually see 200-500 ma, every so often I see 0, and rarely -100 ma or so.

So it appears that the alternator brings the batteries up to around it's output voltage and the alternator current drops, from around 40A to less than 500 ma. In this way it's behaving like the PD charger.

booster · 08-21-2015, 06:16 PM

Quote:

Originally Posted by ptourin

Here's a quick observation about alternator behavior. When the battery was down to 50% and we started driving, I got back up to 100% in about 2-1/2 hours. Earlier I saw around 40A from the alternator, so this makes sense - I think the voltage reading was around 14.1-14.2. Now we've been driving for some time, and the only load is the fridge on 12vdc. Voltage is sitting at 14.05 and when I watch the monitor sample the current, I usually see 200-500 ma, every so often I see 0, and rarely -100 ma or so.

So it appears that the alternator brings the batteries up to around it's output voltage and the alternator current drops, from around 40A to less than 500 ma. In this way it's behaving like the PD charger.

Sounds very similar to the charger, only at lower voltage. That would mean slightly less charge in the batteries, but still with continuous voltage applied, just like the charger.

ptourin · 08-22-2015, 02:36 AM

Yes, that's the way I see it too.

What's a bit confusing to me is the Victron monitor setup. I put the full voltage setpoint at 13.4, since SmartBattery said that the at-rest full voltage is 13.3 - 13.4. But that means that no matter whether I'm charging with alternator or PD charger, the batteries are pulled way over 13.4. So they always read 100% SOC regardless of whether they're all the way up there or not quite. Is the idea that once the charger/alternator goes away and the surface charge dissipates, the battery will drop down to 13.4 (charger) or a bit less (alternator), and then it'll read either 100% or 99%??

Sorry if this is sounding like a Chargers 101 question, but I'm a bit awash in the best way to set up and use the monitor.

I've been also playing with the alarm functions of the monitor, and they're cool - I can configure the alarm by percent SOC, voltage or a combination of both. The alarm is either an icon and flashing LED's or those plus a buzzer - if you press a button the buzzer stops but the icon remains until the alarm state goes away. The internal relay is configured separately from the other alarm functions - all pretty flexible.

booster · 08-22-2015, 02:52 AM

I am not up on the Victron monitor, but if it works like most of the other ones out there, it has an automatic "reset" or "recalibration" or whatever procedure it goes through to get the SOC reading right. It is an odd procedure to be sure.

On the ones other than Victron that I have seen, they look at needing a charged voltage with the charger on, an amp reading to the batteries at that voltage, and a time both of those parameters are held. At that point they say the batteries are full, but many of them don't reset the SOC readout at that point. It won't reset until the surface charge is gone in the discharge phase, and will do the reset at a set voltage like 12.8 volts, that you sometimes can set yourself. With lithium, you are going to have very little voltage drop with discharge, so choosing that point might be very picky and difficult. I really can't say how the best way would be. Can Victron give any guidance for use with lithium?

ptourin · 08-22-2015, 03:01 AM

Thanks - that just put a few more things into place. Yes, Victron does have an auto reset, and I'll have to read again just how it works. They do allow me to set the full voltage point - I think they default it to 12.8, and I set it at 13.4 on the advice of SmartBattery. And yes, there is a Victron North America that I can call for support - there are 2 very helpful guys there, and I've talked to them a few times.

ptourin · 08-27-2015, 06:17 PM

I called StarkPower today and spoke with one of their support techs. He confirms that the advertisement is a bit misleading, and that the PD chargers simply keep the voltage at 14.6 near 100% SOC, and that the current drops to zero as the battery approaches the charger voltage. He also confirms that the charger does not "restart with low voltage signal from battery", as they state on the website - if there's a draw on the battery so that the voltage drops, the charger will start providing power to ramp the voltage back up to 14.6. So it's working as we assumed it does.

He also said that they are not worried about overcharging/overvoltage issues with their batteries constantly connected to the PD chargers - he said that they've done extensive testing over time (he said several years) and that they don't see any battery degradation issues.

I asked him about resting voltage at 100% SOC. He said they consider it to be 13.3-13.4v (same number that SmartBattery told me). I asked him if I could consider this the lith-phosphate analog of surface charge, and he answered that it's different because it takes a good deal longer time for a battery with no load to drop down to that voltage range once the charger is disconnected - he said a week or more. That was a surprise.

As always - I don't know who I talked to and how on top of things he is - one rarely does - but those are the answers I got.

wincrasher · 08-27-2015, 11:55 PM

Essentially you have confirmed my understanding of how they work. Glad to hear they've done some testing and are OK with leaving the chargers on. Can only assume they are also comfortable with long journeys with alternator charging, which is essentially the same methodology.

booster · 08-28-2015, 12:03 AM

I guess I would have more than a few concerns with a company that has known misleading statements in their sales literature and doesn't change them (think Roadtrek also). They make the charger sound like a much more sophisticated full shutoff, monitor, restart style, but at a very low price. Not the high road, IMO, and I doubt they would get my business.

Based on the accuracy of their sales literature, there is little reason to believe they really tested anything either, so I would also take that with a big dose of skepticism.

Yep, I am very judgmental when it comes to things like this.

Jostalli · 08-28-2015, 01:57 AM

Quote:

Originally Posted by booster

I guess I would have more than a few concerns with a company that has known misleading statements in their sales literature and doesn't change them (think Roadtrek also). They make the charger sound like a much more sophisticated full shutoff, monitor, restart style, but at a very low price. Not the high road, IMO, and I doubt they would get my business.

Based on the accuracy of their sales literature, there is little reason to believe they really tested anything either, so I would also take that with a big dose of skepticism.

Yep, I am very judgmental when it comes to things like this.

I'm in full agreement.

You may as well just use a simple power supply and a manual switch.

booster · 08-28-2015, 02:12 AM

Quote:

Originally Posted by Jostalli

You may as well just use a simple power supply and a manual switch.

Yep, because that is basically what they are selling, disguised as a high tech lithium charger.

wincrasher · 08-28-2015, 02:51 AM

Well I don't agree that Progressive Dynamics is purporting their charger to be anything more than it is. If you look at their flyer and manuals, it works exactly as they've indicated. That is now corroborated by their own tech and by two of the battery manufacturers and thru testing by myself and pturin.

By the very nature of how these LiFePo4 batteries seem to work, a sophisticated "high tech" charger is just not needed. A simple charger will suffice. The only thing really to discern them is if an absolute shut-off is needed. There seems to be disagreement on this, so buyer beware. The honesty in the PD offering is that the price reflects what they are supplying. If it was a $600 charger, I'd have a different opinion.

As far as what Stark is posting, their statements were vague enough to illicit a call for clarification. I don't see any deception here. Bad wording maybe, that needs clarification on their site.

ptourin · 08-28-2015, 02:56 AM

That's what I'm having Jean do with the RV now that she's got shore power in Salem MA. I rewired the charger breaker so that nothing else was on it, and I'm having her leave it off. The monitor will start buzzing when I get down around 50% SOC, and I told her that if she comes home and it's buzzing, just press any button on the monitor to shut it up and throw the breaker on - run the charger for at least 3 hours and she'll be at 100%. I'm not so concerned if she leaves it on overnight - from what I'm reading, 14.6 volts for a few extra hours at very low current isn't likely to hurt the batteries much. But I still don't want to leave it on 24/7 yet - not until I understand more about the overcharging issue.

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