I want to build a smaller version of this:
https://www.thepowerstore.com/24v-2070ah-c100-energycell-re-high-capacity-vrla-battery-bank.html
With this battery (or one like it):
https://www.thepowerstore.com/simpliphi-phi-3-2-kwh-high-power-lfp-battery-24v.html
Thoughts? Pitfalls? Alternatives?
http://www.beginningfromthismorning.com/
Follow this guy.He's already done it with batteries from a Nissan Leaf.
I love the ingenuity of developing new ways of using these new technologies.
BUT...
The SAFETY message doesn't often get included in DIY pursuits.
How can these technologies harm you, or your neighbours?
Unfortunately, that knowledge is often buried in scholarly sources, not out in the common media.
Everyone needs to gauge for themselves what risks any particular technology poses, and whether they want to take those risks.
Don't just follow someone else!
One wonders if Madame Curie had known what she was really messing with, would she have continued, miscarriage, cancer, et al?
Expand the experience, go where none other has dared to go, but DO IT WITH KNOWLEDGE OF THE DANGERS!!!
A safe busnut continues to be:
Happy coaching!
Buswarrior
Lots of knowledge here also for years with them. :)
https://www.technomadia.com/lithium/
There are a ton of unique and different battery choices these days. Those are VRLA - valve regulated lead acid - AGM lead acid batteries, a well known and mature technology developed in the 1960's for military aircraft use, but nothing particularly new. You can build your own house bank of commercially available deep cycle AGM batteries in a variety of sizes. Sean, a highly technical old-timer around here that now plays with quite large boat, built a very large house bank out of 8D sized AGM batteries with tremendous success. The point being that you don't need to buy a high end UPS or building battery system designed for large solar systems for your bus - the technology and effectiveness can be equalled with more accessible batteries and inverters. You don't say how large you want to go, I'd venture a guess that a 1,000 AH 24 volt system could be built for around $6,000. Figure $6.40 per 24 volt AH for high quality AGM batteries.
Lithium or similar, including taking Chevy Volt batteries apart, are places I don't go yet. AGM's I've used and abused for many years...
You no doubt know this well, but you design based on known load, time, and recharge capability. Figure what you need to do, for how long, and how long it takes to get back to ground zero, and you can design a system. VRLA AGM lead acid is a very good battery choice if you can afford it or need it's particularly attractive qualities - an 80% depth of discharge, and a very fast recharge rate with the correct voltage regulated charger.
Also do not fail to consider the inherent fire/explosion risks of lithium batteries. Inadequate safety measures can mean that one simple puncture can result in a conflagration of astounding proportions. Life threatening doesn't begin to do it justice. Obviously the risk can be minimized if you know what you are doing but it's not to be taken lightly.
Jim
Quote from: Jim Blackwood on April 09, 2019, 05:35:38 PM
... a conflagration of astounding proportions...
I bet that the smoke tastes really yummy too? Once...
Happy coaching!
Buswarrior
Lithium batteries need thermal management. You need to cool them in hot wheather and warm them if cold (they cannot be charge when it's freezing temperature).
Even a coach converter like Millennium luxury coach won't go for lithium right now, maybe in 2 to 5 years...(look on You Tube).
For now, AGM is the way to go.
Agree on need for thermal mgt but virtually every electric car manages this on lithium packs.
Howdy,
I have had LiFePo batteries in my coach for five years. First, educate yourself about Lithium before you even begin. Lithium is not lithium, there are many different technologies out there. Some are more inherently dangerous than others.
LiFePo can be quite friendly in an RV environment. It does require knowledge of how to charge them without killing them, some sort of battery management system to provide a safeguard against over or undercharging, and a completer understanding that they do not behave like lead acid batteries.
Suggest you take a look at the Battleborn site as a starting place. I have no stock or connection with them, just they have an excellent starting place for learning about what you are getting into. Also, keep in mind that sailors and cruisers have been using Lithium based systems for some time now.
There is also a strong connection between the complexity of the system and what you want to do. If you just want to have a lighter, longer lasting version of the standard 12/24V house system, then the install isn't too tricky. If you want to go all in and run a roof top AC or two, then get ready for complication and big $$$$
Hopefully, anyone that goes down this road, will make accurate records of expenditures to implement this type of system. Then others can compare the cost vs. Gen run time vs actual use or need of systems.
I'll need to consider all of your points before I actually start building a system. I am lucky to have my PD 4590, and I'll want 1000-1200 AH in a system without spending $3,000 on one battery. I like to build my own when possible and the electrical system is the system I'm most familiar with, but if i get new appliances, I'll need to recalculate everything anyway.
I noticed the LFP batteries getting more attention lately and I can use them safely...but I wanted the various points of view. Thanks so much.
Here's another thought. With these batteries we are beginning to get large enough that making your own begins to look like it might be feasible. It's basic technology, a couple of lead plates, a separator, and some acid in a plastic box. By now some of our folks are proficient enough in making plastic boxes (holding tanks) to give it a go. Modern battery plates are stamped with a waffle pattern that increases surface area while lightening the plate but battery capacity is entirely dependent on plate surface area while life is dependent on plate thickness so that's a trade-off. I suspect you could buy a quantity of 1/16" thick lead plate and some glass mat for separators. Optima did it by the simple expedient of rolling it all up in a cylinder but plenty of other approaches are possible, and then you have to stick the plates in a puddle of lead to terminate the cell. Drop it in your case and add acid. Wouldn't surprise me any if the original optima prototypes were dropped into sections of PVC pipe, but overall a plate stack is probably easier to manage and the trimming scrap can be melted down to make the bus bars and terminals. You could make it as large as you want, the issue probably being handling the weight. You could certainly make it longer lasting. And you could add to it rather easily once you made the first one or two.
Jim
Jim - That may be taking the DIY concept just a little bit further than most.In the early years of automobile development though, I'm sure that many did just as you describe using glass jars.
I've read through this, and if the end result is 1K to 1.2K of Ah capacity, the biggest bang for the buck is going to be flooded cell 6v batteries. six Trojan L16H-AC batteries will easily get you over 13K of Ah capacity and probably cost less than half that capacity with other types of batteries. Of course the trade-off would be maintenance and venting requirements.
Black box in the photo is our battery box with four of the L16 batteries. Could easily have added two more to the enclosure with just a little more material. I used PVC board for the material - it's lightweight and easy to work with. Seams are held together with 1" aluminum angle.
While I am one of those people who will build just about anything, I spent enough time (and sacrificed a few pair of jeans) filling batterys with acid to know building them is something I'll forego in favor of buying them. I do however really appreciate the out of-the-box thinking. The ideas and thoughtful evaluation you all provide helps me more than I can express, and I have no doubt when finished, my system will be engineered just as well as a Mastervolt system.
Thus far, I'm leaning towards those Trojan 6 volt batteries that Richard mentioned, but I'm keeping LFP drop ins in the idea folder. I am also thinking of where I will put them, especially given that I haven't finalized a location of the power center, and just about everything is connected to that.
So, under the bus in a bay, or inside the bus? If I go with the L16H-AC batteries they'll need to go in a bay. The LFP can go in the bus, but is that convenience worth it?
Space utilisation and venting drive the agenda.
Can the space upstairs and the space downstairs be equally useful?
Is there any possible opportunity for the power source to give off offensive or poisonous fumes in either normal or a crisis mode?
Choices choices cjoices
Happy coaching!
Buswarrior
With the weight of these L16 batteries, I tried to put as much of the battery box in the center of the bay as was possible. Of course, this meant that I couldn't vent through the side of the bus. Instead I installed a powered fan which vents out the top of the box and down through the bay floor. It only draws a small fraction of an amp while running, and it only runs when the batteries are charging since that's when they produce gas. To switch it on and off, I used a small digital relay which is set to connect power to the fan at a set point just below my float charge rate. It's hard to see in the photo, but it's directly behind the white PVC pipe.
Brushless motor?
no spark condition I hope.
The fan is specifically designed for this application. Used in many solar installations around the world. Not worried about sparks.
http://zephyrvent.com/
I read the FAQs. They state it is brushless. Thanks for that post. I've been wanting to add some kind of ventilation to my batteries, as all it has is a 3 inch mesh covered hole to the outside in bottom of enclosure. That fan is just what I need. I've wanted to provide powered ventilation, but haven't spent any time on options.
This is the controller I used to turn the fan on & off.
https://www.amazon.com/gp/product/B01MUBB6CF/ref=oh_aui_search_asin_title?ie=UTF8&psc=1
This item is no longer available, but there are others out there. I believe it was intended to send a signal to cycle a battery charger on/off, but the current rating for the relay was high enough to use it to power the fan itself.
The only problem I had was trying to track down instructions on how to connect and program the thing - it's rather cryptic and instructions are hard to find. Read through the user comments to find some good information.
Quote from: richard5933 on April 12, 2019, 05:26:15 AMThis is the controller I used to turn the fan on & off.
https://www.amazon.com/gp/product/B01MUBB6CF/ref=oh_aui_search_asin_title?ie=UTF8&psc=1
Thanks, Richard. I looked at Amazon and found this -- which seems to be very equivalent, inexpensive, accurate (according to purchaser comments), good for a small fan or for a relay for larger loads. Very useful! Thanks again.
https://www.amazon.com/Electronics-Salon-Voltage-Disconnect-Protect-Prolong/dp/B018TW0KN2/ref=pd_sim_0_1/134-4854625-7055707?_encoding=UTF8&pd_rd_i=B018TW0KN2&pd_rd_r=3f1e2ed7-5d45-11e9-aa61-a910d2132542&pd_rd_w=uHWnz&pd_rd_wg=kHrXF&pf_rd_p=90485860-83e9-4fd9-b838-b28a9b7fda30&pf_rd_r=3MJGQ70TKW17W2JPTVPA&psc=1&refRID=3MJGQ70TKW17W2JPTVPA#customerReviews
Quote from: richard5933 on April 11, 2019, 03:21:30 AM
Jim - That may be taking the DIY concept just a little bit further than most.In the early years of automobile development though, I'm sure that many did just as you describe using glass jars.
I've read through this, and if the end result is 1K to 1.2K of Ah capacity, the biggest bang for the buck is going to be flooded cell 6v batteries. six Trojan L16H-AC batteries will easily get you over 13K of Ah capacity and probably cost less than half that capacity with other types of batteries. Of course the trade-off would be maintenance and venting requirements.
Black box in the photo is our battery box with four of the L16 batteries. Could easily have added two more to the enclosure with just a little more material. I used PVC board for the material - it's lightweight and easy to work with. Seams are held together with 1" aluminum angle.
Very nice job !
Quote from: richard5933 on April 12, 2019, 05:26:15 AM
This is the controller I used to turn the fan on & off.
https://www.amazon.com/gp/product/B01MUBB6CF/ref=oh_aui_search_asin_title?ie=UTF8&psc=1
This item is no longer available, but there are others out there. I believe it was intended to send a signal to cycle a battery charger on/off, but the current rating for the relay was high enough to use it to power the fan itself.
The only problem I had was trying to track down instructions on how to connect and program the thing - it's rather cryptic and instructions are hard to find. Read through the user comments to find some good information.
What are you using to charge that battery bank ?
Quote from: MagnoliaBus on April 12, 2019, 03:31:06 PM
What are you using to charge that battery bank ?
https://www.progressivedyn.com/rv/power-converters/pd9200-series-rv-power-converters/pd9270-70-amp-rv-convertercharger/
This is how we charge when we're plugged in or on generator. Trojan recommends 10% of max capacity for charging rate, so the 80-amp model would have been ideal. However, that would have really pushed the 120v circuit towards it's upper limit - it's a 20-amp circuit but I don't like to run things continuously at more than 80% of rated capacity. The 70-amp charger can safely run on a 15-amp circuit, so that's what we went with. So far so good.
https://www.sterling-power-usa.com/SterlingPower24volt-to-12volt-dc-to-dc-batterytobatterycharger.aspx
This charges the battery bank at up to 70 amps while on the road.
We've been really happy with both of these. I wired the on/off toggles for the chargers so that both the 12v and 24v plug-in chargers have to be in the off position in order for the 24v-to-12v charger to activate.
We also have a Victron solar charge controller which is connected to the battery bank parallel to the other chargers for when we deploy our solar panels.
When I bought my Trace 2512 inverter/charger, since it could be stacked, I asked the owner of the shop about buying two inverters with a big battery bank to run the A/C's during the night. She asked if I had a Diesel generator, and yes I have a 10kw Powertech genset. She said, just run the generator when you need extra power and use only two 8D deep cycle batteries to keep weight down. Remember-you're paying in fuel to carry all the lead around too. Good Luck, TomC
Quote from: TomC on April 12, 2019, 04:01:44 PM
When I bought my Trace 2512 inverter/charger, since it could be stacked, I asked the owner of the shop about buying two inverters with a big battery bank to run the A/C's during the night. She asked if I had a Diesel generator, and yes I have a 10kw Powertech genset. She said, just run the generator when you need extra power and use only two 8D deep cycle batteries to keep weight down. Remember-you're paying in fuel to carry all the lead around too. Good Luck, TomC
We do lots of camping in the north where a/c is not necessary. Primary consideration for us in getting the larger battery capacity was being able to camp for days (almost up to a week) without the noise of the generator when we want to. If we're staying longer we'll have to run the generator, but usually we'll be off to our next destination before they need charging and everything charges while on the road.
For now, AGM is the way to go. Agreed.
They need to be thermally managed too. But not as closely as lithium. I am told.
Quote from: richard5933 on April 12, 2019, 04:14:44 PM
We do lots of camping in the north where a/c is not necessary. Primary consideration for us in getting the larger battery capacity was being able to camp for days (almost up to a week) without the noise of the generator when we want to. If we're staying longer we'll have to run the generator, but usually we'll be off to our next destination before they need charging and everything charges while on the road.
Like you say, A/C is not necessary where i plan to camp (Canada in the summer, northern Texas in the winter).
Also, i wont install a generator. For the price of a generator i can run the engine and burn some fuel to turn the 450 Amps 24V alternator (that is 300 Amps at idle or 7,2 KW).
Quote from: richard5933 on April 12, 2019, 03:41:58 PM
https://www.progressivedyn.com/rv/power-converters/pd9200-series-rv-power-converters/pd9270-70-amp-rv-convertercharger/
This is how we charge when we're plugged in or on generator. Trojan recommends 10% of max capacity for charging rate, so the 80-amp model would have been ideal. However, that would have really pushed the 120v circuit towards it's upper limit - it's a 20-amp circuit but I don't like to run things continuously at more than 80% of rated capacity. The 70-amp charger can safely run on a 15-amp circuit, so that's what we went with. So far so good.
I've got the 4590: https://www.progressivedyn.com/rv/power-centers/inteli-power-4500-series/
The power center charges the batteries at three different charge rates, depending on what they need. I have all three air conditioners connected to it as of now, and I want the end system to be as safe and as AH heavy as I can afford. From what I've read, the lithium batteries have different requirements, the LFP are supposed to be very low maintenance, but they are so much more expensive that I think the L16 batteries make more sense. The point of space utilization is a good one. I can redesign any of the bay areas to be both a battery area and an off season storage area. And I have a little time to consider if I leave the system totally separated, or if I connect it and use a transfer switch. It would be nice to use that huge generator for both battery systems.
Regarding placement of the battery box, I had a few considerations. I wanted it towards the center of the bus side-to-side, I wanted it out of my way so the rest of the bay was still usable, and I wanted it closed and vented.
To accomplish all this was going to make maintenance on the batteries difficult. Two things I did to help with this were to use thumb screws to hold the lid of the battery box, and most important I installed Trojan's Hydrolink watering system.
The fill hose for the Hydrolink sticks out of a small hole on the front of the battery box facing the bay door. All I have to do to fill all the batteries is connect a hand-pump with a quick connect to the Hyrdolink, drop the other end into a jug of distilled water, and pump till I feel pressure. Takes less then five minutes, so I'm able to do it weekly camping season with no problem.
Once every few months I open the lid to visually inspect the batteries, tie-downs, and cables and clean/adjust as needed.
There are other watering systems out there, but since Trojan had one specifically for their batteries I went with that.
Richard
Your battery box looks great. I am very interested in the fan relay that you use. Can you give us a little more detail in how it is set up?
Quote from: richard5933 on April 11, 2019, 03:21:30 AM
Jim - That may be taking the DIY concept just a little bit further than most.In the early years of automobile development though, I'm sure that many did just as you describe using glass jars.
I've read through this, and if the end result is 1K to 1.2K of Ah capacity, the biggest bang for the buck is going to be flooded cell 6v batteries. six Trojan L16H-AC batteries will easily get you over 13K of Ah capacity and probably cost less than half that capacity with other types of batteries. Of course the trade-off would be maintenance and venting requirements.
Black box in the photo is our battery box with four of the L16 batteries. Could easily have added two more to the enclosure with just a little more material. I used PVC board for the material - it's lightweight and easy to work with. Seams are held together with 1" aluminum angle.
The fan I used to vent the battery box is: https://www.altestore.com/store/deep-cycle-batteries/ventilatorsbattery-fans/zephyr-industries-powervent-12v-battery-box-ventilation-p2287/
Prices range from about $70 to $105. This little fan has been running non-stop for more than a year without a hiccup. Only draws about 3w.
The relay I used was similar to this one: https://www.ebay.com/itm/LM-YN-DVB01-12-12V-Digital-Display-Voltage-Comparator-Voltage-Measurement-Contro/282573442887?epid=676982091&hash=item41cab08f47:g:Y3YAAOSwuilcdtIi
The manufacturer's names change so fast on these things that it's hard to tell, but the specs look like what I have. It takes a bit of research to find good instructions for setting up the relay, but in the end I found what I needed. There is a calibration function in there as well if its readings don't jive with your multimeter. Search for instructions for : DVB01
Mine is setup so that the fan kicks on when the voltage is 13.2 volts or above, and it turns off at a few tenths below that (I can't remember what I used for the 'off' setting.) My research showed that off-gassing begins at 13.2 on my batteries, so that is why I used that number. It's also the float charge for my charger. So, when ever the charger is running the fan is running. (Doesn't matter how they're being charged - as long as the voltage is at a charging voltage the fan runs.
The relay has a normally-open and a normally-closed contact. I used the normally-open contact.
The rating on the built-in relay is something like 10a, so it's able to handle turning the little fan on/off without need for additional relays.
One of the places I found helpful hints on using the menu was an Amazon review on a similar product. Here's what the guy wrote:
Very useful relay, but there is no proper manual and the settings are not very intuitive. There also seem to be some blank unprogrammed features in the settings. DC- and DC+ are the Supply Voltage (5V, 12V, 24V according to the Relay). V- and V+ are the measured Voltage. Product description says DC 0 - 100V, but i have only tested it up to 24V. Short-press SET to turn the voltage display On/Off Long-press SET to enter the settings: Press SWT to switch between P0, P1, P2, P3 menu option. Short-press SET to enter the selected menu: P0: Setting the Function with + and - buttons. Short-press SET to return to menu. P1: Set the Voltage "V1" with the + and - buttons, use SWT to change digit. Short-press SET to return to menu. P2: Set the Voltage "V2" with the + and - buttons, use SWT to change digit. Short-press SET to return to menu. P3: Only displays a flashing "00.0", Buttons don't do anything, unknown option. Short-press SET to return to menu. Long-press SET to exit the settings and return to operation with the selected function. As for the functions: F0: ??? F1: ??? F2: Voltage drops under lower voltage: ON, Voltage rises above higher voltage: OFF ("Charge Monitoring") F3: Rises above higher voltage: ON, Drops below under voltage: ON ("Discharge Monitoring") F4: Relay ON within Voltages set F5: Relay ON outside of voltages set F6 to F9: ??? I tried experimenting with all the other unknown functions, but nothing seems to happen at all, i assume they are not programmed at all. Turning the supply Voltage off an on again, the module remembers the set parameters and resumes its function, but the display always comes on again. Power Draw (12V version): 19mA with relay off (7mA display off), 52mA with relay on (40mA display off)
Hope all this helps. Let me know if you need more information.
When I was driving long distance truck cross country, it never made sense to me for a truck to be run with a 400-500hp engine just to run a 5hp air conditioning compressor, or charge the batteries with 15hp of alternator. Yes you can initially save money by not installing a good Diesel generator, but in the end you'll spend a lot more by inflicting much more ware on the main engine, and in the event of a break down, you'll not have any stand by power (generator) to keep you warm, cool or otherwise. And believe me, we've had an air compressor failure, lost an oil filter, waiting for a repair man where we couldn't run the main engine, but kept perfectly comfortable with the 10kw Diesel Generator running. Good Luck, TomC