Travato LiFePO4 Battery Install

[booster]

That is interesting and what would be expected from he literature. Good that they were able to clarify. It would be interesting to see if the current truly goes all the way to zeor, as the charge profiles I have seen would indicate there would always be some current. In a 100ah battery the current would be very low, I think, if there were any. Probably well under .5 amp.

What it doesn't do, though, is clarify whether leaving the voltage on the battery when full is bad for it. They did punt on that.

AFAIK, loads really don't have anything to do with the problem of float voltage, or higher in this case, on the battery. The power goes straight from the charger to the load, so all the battery sees is the continuous 14.6 volts.

[wincrasher]

I'd think that it would be wise to have some kind of load going all the time if you are going to have the converter plugged in - a couple lights, or a fan, or the radio. Maybe the CO detector is enough. Just to be sure any power is going to devices and not my full battery.

[booster]

Originally Posted by wincrasher

I'd think that it would be wise to have some kind of load going all the time if you are going to have the converter plugged in - a couple lights, or a fan, or the radio. Maybe the CO detector is enough. Just to be sure any power is going to devices and not my full battery.

From all I have seen, the only thing that matters to a battery is the voltage it sees. At that point it will take as much, or little, amperage as it's internal impedance allows at that voltage and SOC (as long as the charger can supply it). Loads might help stabilize the charger, but the PD is truly a power supply so it wouldn't need stabilizing.

[Davydd]

Wincrasher,

Have you followed this thread on Sprinter-Source.com?

Replacing OEM batteries with LiFePO4's

It is a Smart Battery replacement in an LTV Unity.

[Jostalli]

Didn't Advanced RV use Smart Batteries in Muzungu or whatever the name was?

[wincrasher]

Originally Posted by Davydd

Wincrasher,

Have you followed this thread on Sprinter-Source.com?

Replacing OEM batteries with LiFePO4's

It is a Smart Battery replacement in an LTV Unity.

No, but I will now. Thanks! R

[booster]

There is a lot of very scary information on that thread. It appears that no one there has even looked at a preferred lithium charging profile and are randomly guessing of how things will work.

[wincrasher]

It appears like it all works as I understood it to work.

I don't really get why charging profiles matter anyways if you are doing alternator charging. I don't see the PD line of chargers working any differently than the alternator, except a slightly higher voltage.

I think if you go down this path, as I have, that you simply have some operational considerations - isolate the battery if are going to store long term. For short terms, have some kind of load going if leaving on shore power.

[Davydd]

Originally Posted by Jostalli

Didn't Advanced RV use Smart Batteries in Muzungu or whatever the name was?

Until Myst and Imagine were delivered last December most of the Advanced RVs had the Smart Batteries. Our Alvar went out in January but I understand I may have had the first build of the GBS lithium ion batteries but the other two jumped ahead of me in the queue mainly because of my articulated beds I think. They were working on and testing the GBS battery packs long before May 2014 as they had them on display at the first Advanced Fest.

Mzungu was the 2013 concept B and the first I believe with four Smart batteries, 500 watts of solar panels, the VB Air Suspension and other new things. There is nothing wrong with Smart Battery. ARV had just moved onto a newer generation of development where it would be difficult to do Smart Battery with 600-1200ah they now have.

They've used the Silverleaf monitoring system all along which gives SOC readouts and interfaces with BMS and other things for total control. Last May, the Silverleaf rep said their system is the first they've put into a Class B or any RV for that matter below a half million dollars.

The other departures from everyone else in Class Bs was the Rixsen Espar diesel-fired heating and hot water system and the Outback inverter/charger. Great West Van also had those two things because Neundorfer (ARV owner) bought a GWV Legend in 2011, engineered, and had GWV install them on his B. It then became a GWV standard. Neundorfer felt at the time Great West Van was the best B on the market but it evidently didn't fully satisfy him. I understand only one ARV has been built with an Onan generator. The second 270A alternator has been their standard.

I was the first curiosity visitor at Advanced RV in May 2012 when they formally went in business. At the time, other than the Espar and inverter, they didn't have enough differences developed for me to abandon my 2011 GWVan Legend. They talked about them but they weren't ready yet. Two years later the changes were compelling and significant plus I had a lot of ideas I wanted implemented I knew I could not get anywhere else. It is a customer driven company. I am already getting jealous of some other new things coming out of them. I was too early for their 4 x 4 design efforts.

[booster]

Originally Posted by wincrasher

It appears like it all works as I understood it to work.

I don't really get why charging profiles matter anyways if you are doing alternator charging. I don't see the PD line of chargers working any differently than the alternator, except a slightly higher voltage.

I think if you go down this path, as I have, that you simply have some operational considerations - isolate the battery if are going to store long term. For short terms, have some kind of load going if leaving on shore power.

Charging profiles DO matter, that is why the battery makers show the profile you should use.

There is a fatal flaw in using the logic that it leaving full voltage on from the charger is no different than the alternator, and will thus will not do any damage. The flaw is that the alternator charging continuously is also bad---so both are bad, not both are good.

As I explained before, having a load on will make no difference in if the 14.6 voltage hurts the batteries, as the batteries will not even know if the load is on or off.

As I have said many times, I just don't think that there is any good, settled, data on lithium battery use yet. But, there are some things that have seemed to become mainstream recommendations, and one of them is to not leave full voltage on a full battery, not even float levels.

[gerrym51]

Originally Posted by markopolo

In an email, I asked Smart Battery if their batteries could be charged when temperatures are below freezing and if so, what is the minimum temperature at which they can be safely charged.

Their reply indicated that their batteries can be charged at below freezing temperatures but it did not specify how low the temperature can be.

If you live in a colder climate it would be worth sending them some specifics about the temperatures you would expect to use the battery in and get a more specific reply.

Mark-you know that a lithium battery cannot be charged below 32 without the battery plating-so unless the battery warms itself how can it>

[Davydd]

Technically it is possible to charge batteries when the air temperature is below freezing. The question should be in regard to the actual battery temperature. My batteries were still above freezing when the temperature was zero F. outside. There was a time lag when not in use for the batteries to start to drop near freezing. I'm sort of guessing if you can stand the weather camping in a Class B that maybe it will not be an issue on the road. Of course I will have to wait until this winter again to do any testing but I went from January 27 to February 1st with the temperatures always below freezing day and night and the batteries stayed above while I was driving home 800 miles and three overnights from Advanced RV. It was after I stopped at home for a couple of days before heading south and letting my van sit unused that the batteries started to drop in temperature. Once I headed out again for two days with air temperatures still below freezing the batteries stayed above freezing.

[wincrasher]

David's pack has heaters built into it, correct? Don't know if they are switched, or come on automatically on low temp or what.

Eventually I plan to fashion some heating and insulation for those rare occasions I need to drive the van starting out below freezing. I think a seat heater pad and some reflectix will fit the bill. You'd switch it on for 15 mins or so to preheat before starting the engine.

They are fine to discharge at very low temps.

I don't have any plans for camping in the cold. What could happen is I pull out from my home in 25 degree weather and head south to Florida. I'd certainly be above freezing in about 3 hours drive from the house.

[gerrym51]

i think you misunderstand me. I agree some companys have heaters or some other way to warm the lithium batteries. however when this is happening they are not below 32 and charging-they are at a temperature that is higher than 32 so they can be charged.

smartbattery told Mark that their batteries could be charged below 32 degrees

they did not say anything about warming the battery at all.

in my study of BMS for lithium i read that most times they prevent the battery from accepting any charge below 32.

[booster]

IIRC I read somewhere a while ago that the Smart Battery just had high and low voltage cutoff protection, with no balancing or temp cutoffs. I wish I could remember where I saw that.

on edit

Looks like remembered wrong or source was wrong-here is what Smartbattery site says.

• Low Voltage Protection Switch - Automatically disconnects at 8V
• Over Voltage Protection Switch - Automatically disconnects at 15.8V
• Short Circuit Protection Switch - Automatically disconnects
• Reverse Polarity Protection Switch - Automatically disconnects
• Internal cell balancing - Automatically balances cells
• Charge Balancing - Independent balancing for multiple batteries connected in parallel or in series.

[wincrasher]

I spoke with them too before I purchased my battery. The only reason I'd add some heating is because my battery is mounted outside, under the van. If it was in the cabin, I wouldn't bother.

There is no thermal protection. They do not recommend charging below 32 degrees. He reiterated that there is a full BMS. The closely match the cells, so load balancing often is not needed, but the circuitry is there to do it. He also reiterated I can draw the battery down 100% each cycle.

Victor was my salesman too. He's not an engineer, but a salesman, FWIW, and what they seems to say varies a bit from time to time.

But they do have a 5 year warranty. Nobody else does. If I loose capacity, you send it in and they take it apart, check it and either repair or replace and return it to you. That is why I was comfortable with buying it.

[Davydd]

Originally Posted by wincrasher

David's pack has heaters built into it, correct? Don't know if they are switched, or come on automatically on low temp or what.

There are two heating pads sandwiched between a pair battery packs with four battery packs in all. They are thermostatically controlled to come on when the temperature drops to 36 degrees (maybe 40) I believe. As I was mentioning the air temperatures were colder than the battery temperatures which were for the most part above 40 degree most of the time. If they are sitting there with no draw from them then they are going to drop to the ambient air temperature much faster. I initially drove home from ARV in always below freezing weather, mostly in the teens, but until I stopped at home the batteries stayed above 40 degrees.

This business about not charging when batteries (not air temperature) are below freezing wasn't commonly known as little as a year ago in all the reading I've done. There is probably a lot of catching up to do. ARV knew it. If my heating pad system were to fail I have a backup. My batteries would simply disconnect until the temperature can be brought back up with heated space, external heat, driving to a warm place or waiting for the temperature to come back up. On February 2 I headed south and haven't encountered the problem since. It will be about November before I can observe or test again.

[Jostalli]

Originally Posted by wincrasher

I spoke with them too before I purchased my battery. The only reason I'd add some heating is because my battery is mounted outside, under the van. If it was in the cabin, I wouldn't bother.

There is no thermal protection. They do not recommend charging below 32 degrees. He reiterated that there is a full BMS. The closely match the cells, so load balancing often is not needed, but the circuitry is there to do it. He also reiterated I can draw the battery down 100% each cycle.

Victor was my salesman too. He's not an engineer, but a salesman, FWIW, and what they seems to say varies a bit from time to time.

"Varies a bit from time to time"? Oh I'd say that is an understatement. Here is what Victor told Peter Tourin (quoted from Sprinter-Source Sprinter-Forum - View Single Post - Replacing OEM batteries with LiFePO4's

"I talked with Victor at SmartBattery yesterday. Here's some info from the call - some of this pertains only to SmartBatteries, some to LiFePO4 in general:

Most surprising: SmartBatteries have no BMS, only under- and over-voltage protection via internal relay. Victor claims no balancing is needed because all 80 cells are very closely matched at factory. We'll see what that implies for long-term battery health..."

[booster]

At least now I know where I heard the info on the protection circuits.

[gerrym51]

Originally Posted by Jostalli

"Varies a bit from time to time"? Oh I'd say that is an understatement. Here is what Victor told Peter Tourin (quoted from Sprinter-Source Sprinter-Forum - View Single Post - Replacing OEM batteries with LiFePO4's

"I talked with Victor at SmartBattery yesterday. Here's some info from the call - some of this pertains only to SmartBatteries, some to LiFePO4 in general:

Most surprising: SmartBatteries have no BMS, only under- and over-voltage protection via internal relay. Victor claims no balancing is needed because all 80 cells are very closely matched at factory. We'll see what that implies for long-term battery health..."

well i guess as long as they warranty them for an extended period it can't hurt