Lithium swap anyone?

[booster]

Originally Posted by Bud

Yes, Mr. booster stated that I had trained myself like a puppy or something like that. Hey, I'm a full grown dog now, just took some time.Bud

IIRC the comment was something like the owners of new puppies that are being housebroken seem to be trained to put the pup out based on signals from the pup, so the owners get trained by the pup before the pup gets trained eventually.


So in this case, Bud's power system would be the pup giving signals and he would be the "owner in training". So I guess we would have to say I called his van a pup (no an old dog)?

[Santiago]

Originally Posted by avanti

My understanding is that the reason for the "rest" period is simply that it provides a standard condition for measurement.

Hi Avanti, yes I think the true charge condition of a battery is resting voltage as that is its baseline, standard condition for measurement as you well stated.

Relying on voltage readings while in service is a reasonable system health indicator if you keep in mind what loads are in play at the time. I did it that way for years.

Now on my new lithium build, I prefer to monitor how many amperes are left in storage. A flat lithium voltage curve is not helpful in determining remaining battery ampere level.

Santiago

[kite_rider]

Originally Posted by Winston

Our concept of 'resting voltage' is to determine what the voltage is AFTER these temporary sagging/recovery effects have 'run their course'. We find that the pack voltage will 'recover' slowly for several hours after each discharge segment. We consider the recovery to have 'run its course' when the pack voltage no longer increases - - generally we require several hours of 'no (voltage) change' before taking our reading. To be on the safe side, we've been letting our pack 'rest' for 10 hours after each discharge segment..

10 hours is a long time to wait if your are using the van in any meaningful way. None the less, it's good to know how you define this measure.

For me, I'll start recording my 'resting voltage' when I get back from camping trips and try to calibrate it against measurements I take right at the end of the trip (before the batteries can settle). My home made battery management tools only work with real time measurements...

[kite_rider]

Originally Posted by Santiago

Now on my new lithium build, I prefer to monitor how many amperes are left in storage. A flat lithium voltage curve is not helpful in determining remaining battery ampere level.

Santiago

Please share your setup and observations once you get some data. I'm also measuring the amps in and amps out on my battery and have determined that something just isn't adding up.

For example, I reset the 'Charge Meter' to zero when I was about at 45% SOC. I charged to about 85% with a positive 85Ah on the meter. While camping for several nights I observed consumption around 25 to 45Ah. However on each charge cycle, the total on the Charge Meter would creep up. Like 94 or so after the first cycle. Then 105 on the next, etc. Right now, after 'resting' for a few days and after I used a fair amount of power to dump the tank and clean up I'm seeing 125Ah on the meter (screen shot attached). This can't be right; it should be 85Ah or less.

In the mean time, I'm following the battery specs and ensuring that I don't charge any cell over 3.6V nor do I allow a cell to discharge below 3.2V as measured for at least 3 seconds at any time during charging or discharging. Seems to be better safe than sorry..

[Santiago]

Originally Posted by kite_rider

Please share your setup and observations once you get some data. I'm also measuring the amps in and amps out on my battery and have determined that something just isn't adding up.

Hi Kite Rider, yes I will share all the electrical I manage to cobble together when I have something to show.

On your monitor, are any negative returns bypassing the monitor's shunt ?

As I mentioned earlier, my scheme is exactly the same as another Promaster member (tgregg) is using successfully to manage his lithium bank. His monitor is the Victron 700 series with built in high and low contacts that turns charging on and off. I believe I know another Promaster DIY fellow that used same charging control scheme when charging his lithium from the chassis battery using the Victron monitor and as far as I know is happy with it.

Santiago

[GeorgeRa]

Originally Posted by booster

What I have read, but have no idea if it is gospel, is that the rest time in lead acid batteries is needed to allow the electron migration through the battery to finish and be uniform. It was referred to as surface charge in reverse, as it gives a similar false actual voltage, but in the opposite direction compared to surface charge. I don't know it it also applies to lithium, and if it does, would it take as long with their high charge and discharge rates?

.........................

I have BlueSea OLED mini voltmeter on the galley front panel. I found it to be a highly visible reference point, it uses 10 mA so it is on all the time. Certainly, doesn’t provide the same information as SOC computed from Ah tally.

I think that during charging electrochemical capacitive double layers at anode and cathode are formed with some level of impedance. A double layer a layer with ion concentration gradient from low at the electrode to high towards the electrolyte. After charging this double layer goes away (ion diffusion) reflected in a lower resting voltage.

[Winston]

Originally Posted by kite_rider

10 hours is a long time to wait if your are using the van in any meaningful way. None the less, it's good to know how you define this measure.

Don't misunderstand . . . we're not proposing using voltage with, or without, long waiting periods as a real-time method for monitoring and controlling our house battery. We use a coulomb/amp-hour 'counting' meter as many on this forum do for real-time monitoring.

We undertook these tests, in part, as a curiosity, to establish a datum, and to measure overall pack capacity. We also wanted - - as most SOC vs Voltage graphs depict a family of curves under varying loads - - to create a graph of SOC vs No Load/Resting Voltage.

Originally Posted by Santiago

As I mentioned earlier, my scheme is exactly the same as another Promaster member (tgregg) is using successfully to manage his lithium bank. His monitor is the Victron 700 series with built in high and low contacts that turns charging on and off.

In view of the continuing 'discussion' about 'drop-in' lithium replacements, it is noteworthy that TGregg's approach was motivated by the belief (one we support) that lithiums should not be subjected to the continuous 'high voltage' of a standard alternator programmed to maintain AGM batteries fully charged. We think others desirous of charging a lithium house battery from a standard Class B alternator should implement TGregg's system for terminating charging at a predetermined (non-100%) SOC level.

Fortunately with our 2nd alternator (with its external Balmar regulator) we are able to 'lithium program' the alternator (as we also do with our solar and shore power chargers) and don't have to rely on a BMS-generated SOC signal to interrupt charging.

[booster]

Originally Posted by Winston

Fortunately with our 2nd alternator (with its external Balmar regulator) we are able to 'lithium program' the alternator (as we also do with our solar and shore power chargers) and don't have to rely on a BMS-generated SOC signal to interrupt charging.

How do you have the Balmar set for the DIY "lithium" program? Looking at the Balmar literature, I have never seen a way to do full shut off or to use anything other than changing voltages and max times, and then relying on the algorithms to do their thing. Are you just setting charge and float to your ending voltage?

[Winston]

Originally Posted by booster

How do you have the Balmar set for the DIY "lithium" program?

The Balmar, like most smart chargers, is set up on the assumption that the user wants a Bulk, Absorption, Float charging profile. We don't. We program the Balmar like we do our other chargers (the Magnum 2812 and the MidNite Solar Classic) for Constant Voltage operation. But unlike these two other sources, we don't regularly use the 2nd alternator and, when we do use it, we use it manually in the sense that we manually turn it on and, thereafter, monitor the battery's SOC and, again manually, turn it off when our SOC target is reached. One other significant difference is, we use the 2nd alternator to fast charge our lithium pack so, to that end, we have chosen a much higher Constant Voltage (13.8 volts) than we ordinarily run with our other chargers (13.4 volts). We're contemplating raising the 2nd alternator to 13.9 volts hopefully increasing the charge rate without exceeding temperature limits.

One other significant parameter to note respecting the Balmar, we have set the Bulk Mode duration to 8 hours. As we never drive that long, anytime we use the 2nd alternator it is in the Bulk Mode at 13.8 volts.

[booster]

Originally Posted by Winston

The Balmar, like most smart chargers, is set up on the assumption that the user wants a Bulk, Absorption, Float charging profile. We don't. We program the Balmar like we do our other chargers (the Magnum 2812 and the MidNite Solar Classic) for Constant Voltage operation. But unlike these two other sources, we don't regularly use the 2nd alternator and, when we do use it, we use it manually in the sense that we manually turn it on and, thereafter, monitor the battery's SOC and, again manually, turn it off when our SOC target is reached. One other significant difference is, we use the 2nd alternator to fast charge our lithium pack so, to that end, we have chosen a much higher Constant Voltage (13.8 volts) than we ordinarily run with our other chargers (13.4 volts). We're contemplating raising the 2nd alternator to 13.9 volts hopefully increasing the charge rate without exceeding temperature limits.

One other significant parameter to note respecting the Balmar, we have set the Bulk Mode duration to 8 hours. As we never drive that long, anytime we use the 2nd alternator it is in the Bulk Mode at 13.8 volts.

I kind of guessed it would be something like that if you didn't do the attempt at automatic function, which the Balmar isn't all that good for.


We have AGM on Ample Power regulator that runs both alternators, so don't disconnect completely. I can force to float, though, and do that manually, much as you do, as the Ample Power also sucks at automatic. I read SOC indirectly by a dash mounted ammeter to see battery charging amps. I take it to float when we hit a point that the solar will handle to finish off the charge automatically.

[wincrasher]

I don't have a high opinion of the Battleborn folks or their batteries. They are telling people that they need no lithium charging profile on your charger or solar controller. They are claiming true "drop in" to existing vehicles. I see nothing that tells me they aren't just another "sticker boy" - putting their brand on a box of substandard chinese cells.

[hbn7hj]

Originally Posted by wincrasher

I see nothing that tells me they aren't just another "sticker boy" - putting their brand on a box of substandard chinese cells.

Could be. What indication should we users of Battleborn see to indicate you are correct? I don't know of anyone that doesn't charge with a lithium profile, regardless of what they say. I charge till the current begins to drop with a PD lithium charger.

Still works after almost a year. $2000 compared to the Victron $28,000 (or is it $7000 for 200AH) seemed worth the gamble to me. If they fail I'll post it here.

[hbn7hj]

The purpose of this thread was to see if anyone took them up on their claim and made a direct swap. Apparently no one has.

AMSolar is at $3875 for a 200 amp hour system.

[booster]

Originally Posted by wincrasher

I don't have a high opinion of the Battleborn folks or their batteries. They are telling people that they need no lithium charging profile on your charger or solar controller. They are claiming true "drop in" to existing vehicles. I see nothing that tells me they aren't just another "sticker boy" - putting their brand on a box of substandard chinese cells.

I can't speak for longevity and especially in a true drop in applications, but based on their website, I have never been particularly impressed. Their claims and comparisons are highly manipulated and in some cases blatantly inaccurate on the website, which certainly doesn't mean that the batteries are bad, but IMO does speak for their ethics. With even a severely shortened life compared to claimed, we are talking years of use, so it will be a while before we really know much for certain.


I think the whole lithium battery market is still kind of the wild west, so there will be plenty of changes coming, new vendors showing up, other vendors going away. It is just the nature of new and not yet stabilized technology.

[GallenH]

hbn7hj: did you ever post a simple schematic of your setup on another thread? I'm just interested in what I might have to do to implement the type of system that you have. I find it very interesting and have followed various threads since, I believe, you started your work. Just can't remember if there was a simplified diagram that indicated the various components and their placement. Please don't think that there is a general lack of interest. A hybrid system is extremely interesting to many of us, especially those with older RVs that might be considering upgrading. Cheers!

[hbn7hj]

Originally Posted by GallenH

hbn7hj: did you ever post a simple schematic of your setup on another thread? I'm just interested in what I might have to do to implement the type of system that you have.

Booster posted this one. It doesn't have the second DC to DC charger between the alternator and lithium battery

http://www.classbforum.com/forums/at...0&d=1523755284

Anyone wants to do it just start another thread and we will work through it. I've got the component placements worked out for a Roadtrek Chevy 190P. You will just have to get creative for something else. Space is so limited in a B.

Because it charges so readily you don't need a lot of capacity. I have no interest in running A/C off an inverter but all you have to do is add more batteries and an inverter if that is your thing.

About $1400 for 100AH lithium installed inside. The 50 amp Kisae charger was another $360. The 30 amp was $240.

[GallenH]

Thanks for the info! Much appreciated.

[hbn7hj]

Just a little rambling here. Experience says every system will be different. I've put in two and they are not alike.

The basic principle is the lithium battery goes inside and an A-B Both switch separates LA from Li. If you store in cold country it would be good to make the Li easily removed to take indoors. Mine are not. The second principle is the lithium battery is used to charge the LA through a DC to DC charger to a 100% state of charge.

The differences are in charging from generator, solar, or alternator. The configuration you choose will depend on your use pattern and whether or not you want controlled charging from the alternator which my class C does not have, or need. The class B does not need an AC charger for the LA battery. Whatever the converter comes up with is good enough.

I charge both battery banks to 100% daily so I don't need much total capacity or high current charging. Some want to go days without full recharge. The A/C from battery guys need high capacity and high current charging.

On another note I have kept the absorption refrigerator off the last two trips and used a compressor cooler. I do enjoy not having to mess with level and I suspect there is a compressor fridge in my future and a second Li battery for the class B.

Myth Busters just had a program on the fire hazard of lithium batteries. The ones that burn are called Lithium Polymer.

RVs use Lithium Iron Phosphate LiFePo4.

The link has a discussion of LiFePo4 safety.

https://en.m.wikipedia.org/wiki/Lith...battery#Safety

[donordad]

I have upgraded my 99200P to a 125 amp LifeBlue lithium battery that I purchased from Starlight Solar. I had an issue with my own alternator; it started out cold with 14.2 Amps but dropped to 13.2 when warmed up. I now get over 50 Amps to the battery. I upgraded my converter to one that puts out 45 amps at 14.4 volts. As I only use less than 50 Amps each day (I use propane on our fridge), it charges up fairly quickly. I am going to add solar soon, but as we don't usually stay in one place longer than a few days it's not an issue that demands immediate action. I heartily recommend switching to lithium. My battery will provide more usable amps than two 6 volt batteries. It'll also charge much faster, and is waay lighter! It will also last from 2 to 5 times longer than AGM or wet cell batteries, with zero maintenance.