Alternator questions re converting to lithium

[rob_gendreau]

My AGM house batteries are fading fast, so replacement time.

Given the current price of AGM vs LiFePO4 lithiums ($400ish for say 125Ah AGM vs $950 for 100Ah lithium it makes senses to me, given the lithiums should last longer (especially in my current situation, where battery abuse is going to be worse). A bit more to upgrade some components (I was going to do some of that anyway), and I also get some weight savings and can make a more tidy set up.

Anywho, I believe I have a Ford OEM heavy duty alternator, which was I think rated at 180A. Other than charging the house batteries, and say occasion AC use and radio I don't put much extra load on. Sportsmobile wired my van for basically 40A to the battery from the van electrical, which was pretty standard for 2001.

So given that, I can live with existing wiring. What I'm wondering about is whether I have to yank the isolator; I have an original and not sure what it is, but basically a dumb one if I recall. What I'd like to do is install a Sterling BB1230 on the wire coming from that to the house battery (inside in my van). Would that work? in its default mode the Sterling doesn't come on until it senses 13.2v for like a minute or so, so it would seem it should work. For those unfamiliar it can boost voltage to the lithiums to 14.6 (or 14.4 depending on what I want to use) for charging on the lithium setting (which is some ways simpler than for AGMs, although it can be used for that too).

And the Sterling documentation seems to suggest it's optimal to connect the negative from that unit to the van battery itself, which seems like a pain. Would there be any issue just connecting to my existing ground where SMB connected it from the house battery?

[Scalf77]

A couple of observations. I believe the heavy duty alternator is more in the 130 - 140 range. Also, the fact that sportsmobile fused or had circuit breaker for 40 amps, has no real bearing on whether it is ready for Lithium.

That said you are probably correct your van comes with and diode based isolator , so the first step is to return that back to the original status. This will most likely be as simple as taking terminal A off and going to the starter. If the wire gauge of the wires going to A and from 1 to starter are the same you could probably just use a butt joint to connect. Now as far as using the existing wiring to go to your new Sterling BB1230, that would depend on the existing wire size and length to location you are mounting the unit. I suspect that the existing wire is 10 gauge. Sterling's recommendation for up to 25 feet is 10 gauge, and 8 gauge for 30 feet. Depending on how much voltage drop you want to tolerate, i would think that is on the low side, I could easily see myself putting in 8 gauge for shorter runs and 6 gauge for longer runs. I would not worry about going directly from BB1230 to ground on battery, if that presents a difficulty, I would up-size the ground cable from battery to frame or add the same gauge you are using on positive side.

I would hope whoever you are purchasing your Lithium from would have some directions for the needs of the battery. They are not drop in compatible to your existing set up.

If you wanted some of the benefits that Lithium provides (outside of weight) you could look at Oasis Firefly Carbon Foam AGM battery. This will give the deeper discharge capabilities, longer cycle life, and resistance to Partial State of Charge degradation than a standard AGM battery. It would most likely be a cheaper switch in the long run.

-greg

[rob_gendreau]

Originally Posted by Scalf77

A couple of observations. I believe the heavy duty alternator is more in the 130 - 140 range. Also, the fact that sportsmobile fused or had circuit breaker for 40 amps, has no real bearing on whether it is ready for Lithium.

That said you are probably correct your van comes with and diode based isolator , so the first step is to return that back to the original status. This will most likely be as simple as taking terminal A off and going to the starter. If the wire gauge of the wires going to A and from 1 to starter are the same you could probably just use a butt joint to connect. Now as far as using the existing wiring to go to your new Sterling BB1230, that would depend on the existing wire size and length to location you are mounting the unit. I suspect that the existing wire is 10 gauge. Sterling's recommendation for up to 25 feet is 10 gauge, and 8 gauge for 30 feet. Depending on how much voltage drop you want to tolerate, i would think that is on the low side, I could easily see myself putting in 8 gauge for shorter runs and 6 gauge for longer runs. I would not worry about going directly from BB1230 to ground on battery, if that presents a difficulty, I would up-size the ground cable from battery to frame or add the same gauge you are using on positive side.

I would hope whoever you are purchasing your Lithium from would have some directions for the needs of the battery. They are not drop in compatible to your existing set up.

If you wanted some of the benefits that Lithium provides (outside of weight) you could look at Oasis Firefly Carbon Foam AGM battery. This will give the deeper discharge capabilities, longer cycle life, and resistance to Partial State of Charge degradation than a standard AGM battery. It would most likely be a cheaper switch in the long run.

-greg

The existing wiring from the isolator (and alternator/battery to that) is 8 gauge, fortunately.

I've since discovered a DC DC buck boost converter that also includes a solar MPPT controller, and will probably use that instead of the Sterling unit. About the same price, and I need to replace my existing solar controller anyway. It's a Redarc, and I think it's 25A to the batteries.

And BTW, the Battleborn LiFePO4 are pretty much drop ins. I won't be doing that, but it is a nice feature of their batteries apparently.

I've thought of the foam batteries, but still not convinced. Seem to still lag behind the LFP in charging time, although because of their good performance at partial charges that's not as much of an issue as with my existing AGMs. And they are cheaper by about a factor of two. Know of any long term reviews of them? I got tired of wading through sites that had only used them for brief periods.

[Scalf77]

You might want to check out KISAE DMT-1230 or 1250, it too has a solar charger. I am currently running one in my rig and have installed in others. You can see my write up here http://www.sportsmobileforum.com/for...tml#post256168

For the DMT-1250 I am running 2 gauge from start battery. I have not got any real data yet on the Carbon Foam Battery, but have installed in some rentals and will be monitoring data. I also installed the Balmar SG200 battery monitor on those, it provides some good history data.

I am no more concerned with Carbon Foam than I am with Lithium. We see great data coming from lithium sites, but they are usually under laboratory conditions, not real life in the back of an RV conditions. Who has ever got 100 watts out of a 100 watt solar panel. When my Lifeline 4D goes I would have no problem replacing with two of the Carbon Foam.

I have convinced myself if I go lithium on my next RV, I'll go big and go 48 volt.

[rob_gendreau]

Originally Posted by Scalf77

You might want to check out KISAE DMT-1230 or 1250, it too has a solar charger. I am currently running one in my rig and have installed in others. You can see my write up here http://www.sportsmobileforum.com/for...tml#post256168

For the DMT-1250 I am running 2 gauge from start battery. I have not got any real data yet on the Carbon Foam Battery, but have installed in some rentals and will be monitoring data. I also installed the Balmar SG200 battery monitor on those, it provides some good history data.

I am no more concerned with Carbon Foam than I am with Lithium. We see great data coming from lithium sites, but they are usually under laboratory conditions, not real life in the back of an RV conditions. Who has ever got 100 watts out of a 100 watt solar panel. When my Lifeline 4D goes I would have no problem replacing with two of the Carbon Foam.

I have convinced myself if I go lithium on my next RV, I'll go big and go 48 volt.

Ah, thanks for that. Looks like you've got a nice installation. So the KISAE, just to be clear, is a buck boost DC to DC unit as well? Perhaps I missed that on their web page.

I do know a lot of friends with the LFPs and they seem to work great. For the type of stuff I do it's always going to be a compromise between short charging times and storing the power. The option with the foams is interesting, if I could find a way to maybe cram another one in. Aargh. So many variables. Thanks though; your installation thread is great.

[rob_gendreau]

BTW, another question. I am going to have a Sterling available for some testing with my existing setup.

The existing isolater has A to alternator, 1 to vehicle/starter battery, and 2 to house battery. The wires SMB put in a rather short and a bit of pain to deal with. Can I get around the isolator by simply moving 2 (house battery) to 1 (vehicle battery) on the isolator terminal, using it like a bus? and just leave the alt A in place? would spare me some work when I have to give the Sterling back after testing it.

[Scalf77]

I expect that would work for test purposes.


-greg

[capnkurt]

Hi Rob,

I wanted to chime in here, since I recently (December 2018) installed two 100AH Battleborn lithiums to replace my lead-acid Exide Nautilus batteries.

Since my old batteries were really shot, (lack of maintenance - water level got too low) I needed something to replace them pretty urgently. I thought about getting the same Nautilus batteries again, since I really liked their performance, but I knew that I would have to keep up on the maintenance better if I wanted them to last longer than a couple years. This would have meant checking the water levels regularly in addition to what I was already doing as far as charging: always plugging the van in to keep the batteries topped off and fully charged with my Progressive Dynamics 9100 series charger/converter with the Charge Wizard pendant installed, and making sure to never discharge the batteries below 12.2v. Additionally, I had to use my Zamp 200W briefcase solar panels to keep the batteries from draining too low during camping trips - even when only camping for a couple of days. For reference, I use the batteries to run our fridge, lights, furnace, water pump and the stereo.

I wasn't too keen on having to maintain new batteries, since I've already got too many things that need attention (who doesn't?). Also, having to plug the van in constantly was a nuisance due to the fact that I've got a single-car garage and one-lane driveway and they get obstructed when charging the van. That's when I decided to look into the lithium battery options that were available. Having experience with lithium in other hobbies, I knew that I would appreciate the positives that it had to offer. After speaking with the guys at Battleborn, I decided to bite the bullet and purchase their batteries.

I spoke with Greg here on the forum about what it might take to get my system ready for lithium, and he recommended the Kisae battery-to-battery chargers as a way of keeping my alternator from getting fried. Knowing that I will ultimately install this B2B charger, I decided to take Battleborn's advice and just bolt up the new batteries as a direct replacement for my old lead-acids to see what would happen. I knew this was a risk, as extra-heavy loads on my alternator are sure to kill it prematurely.

Dusty's (my van's) house battery charging system consists of the PD charger/converter mentioned prior and the stock, high-output alternator. A Sure Power 16023A, 160amp battery isolator is mounted under the hood. All wires between the alternator/isolator/batteries are at least 2ga. I use a Trimetric 2030-RV to monitor the batteries' state of charge and current flows.

The new batteries fit perfectly where the old group 31s were installed, under the gaucho inside of two plastic battery boxes. The boxes were vented, so I plugged up all holes leading into and out of them. I charged the batteries up the first time by plugging the van into shore-power and turning on the charger's boost mode via the ChargeWizard pendant. This is the exact method recommended by Battleborn. It is NOT necessary to get a specific lithium charger if you can charge the batteries with at least 13.7v from your regular charger. It just so happens that the PD9100 w/pendant is one of the approved setups by Battleborn. Also, the SurePower isolator that I have is one that they have found to work with their batteries. Of course, this has left me with the one weak link: my alternator. I had my alternator rebuilt a couple of years ago by a company here in San Diego after it failed. I can't remember if they did any sort of upgrades or not, but in any case, I have not yet had any issues with the rebuilt unit.

As far as the performance of the batteries is concerned...I am absolutely amazed!!! Since installing them, I have not plugged the van into shore power after that initial time. The batteries are at 95-100% charged by the time we return from our typical camping trips, which consist of about 2 - 2.5hrs of driving to get home. The batteries are getting down to about 50 - 60% capacity left after a two-day stint, running the fridge, lights, stereo and the furnace when necessary. I also have to mention that now when using the fridge, we can set the thermostat to colder temps without worrying about running the batteries low. With the lead-acids, the furnace could only be used for one evening, set at 60 degrees, before the batteries would need to be recharged by running the van early the next morning. This was when the lead-acids were in perfect shape, too! Now, we can set the furnace's thermostat to 68-70 degrees and run the fridge colder for two days straight and still have 50% capacity remaining. Another thing about the new batteries that I'm really enjoying is the fact that I no longer have to haul my heavy solar briefcase along on the shorter (2 day) trips. It's a striking improvement over the old batteries, and I highly recommend getting the lithiums if you can.

We camp in the Anza-Borrego desert very often, with occasional trips to the mountains in southern California. Because of this, we rarely see temps drop into the 30s. Obviously, the location of our batteries (inside the van) allows us to keep their temperatures up to where charging/discharging the lithiums isn't an issue. I'm sure that an external battery box and camping in cold climates would make it so that the lithiums aren't an option.

Now, I'm just waiting to see what happens with the alternator. If it fails, I'll have it rebuilt again and then install the B2B charger. There's no need to replace the charger/converter, so I'm all set there. I'm planning on permanently installing the solar panels on the penthouse, so that will only improve my capacity to dry camp.

I hope all this rambling helps out, and if you have any other questions, feel free to ask!

Kurt

[rob_gendreau]

Wow, Kurt, thanks for that. I have a very very similar set up going in, although I'm not sure of the brand of isolator I currently have. Somewhat lighter wire too; 8 gauge with 40A fuse. And an alternator I worry about.

I am still kind of curious about the Kisae. I am thinking that if I go the lithium route I'd just disconnect the alternator to isolator wire (but keep it for future possible use) and then connect up the other two (from van batt to house batt; could use an existing terminal block I have or maybe just one post of the existing isolator, since it's there. Then the Kisae in back. It's cheaper than the Redarc I looked at, and allows for a remote dongle which would be really handy; I hate having to dive around under the gaucho to see if my solar is working, etc and for doing trouble shooting.

A couple of questions though: I'm wondering about having a cutoff between the Kisae and van battery. I occasionally need to charge the van battery, and I would assume that this would then trigger the Kisae, which I might not want. The Redarc has a way of wiring to an ignition-on source instead of just relying on voltage. But I haven't yet found a convenient spot to wire in the battery switch, which I'd like to put where the isolator is. But I haven't found anything with terminal bolts on top or that's low enough profile and easy to reach under the plastic reservoir.

But lots of good info. I've been impressed with Battle Borns so far.

BTW, did you opt for any method of warming them? I recall the BMS had temp sensors so that they cut off charging around 30F or so, but since I camp in cold a lot be nice if could warm them. The Relions have some internal method of doing that to some extent, maybe just an internal heating pad.

[capnkurt]

Hopefully, Greg will be able to offer you some insight as far as hooking up the B2B and whatnot - I don't feel comfortable with guessing about the cut-off switch either, since my system doesn't have one, but I can see where it would be very beneficial in the situation you describe.

I haven't looked into keeping the batteries warm. We are never in very cold conditions, but if we were planning a trip in a cold climate, I would think that a heating pad under the battery would suffice. The temperature under the gaucho seems to stay fairly stable as long as we're running the furnace/van to keep warm. I don't know if a battery heating pad exists with a thermostat, but that seems like it would be great. Maybe even something that turns off if voltage reaches a programmed setting?

I looked at Relion batteries as well, but I didn't realize they had a method of temperature regulation built-in. That would be a great feature for those in cold climates. I went with Battleborn simply because I found more testimonials online.

Kurt