House battery bank

[daddysgirl]

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.

[richard5933]

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.

[Jcparmley]

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?

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.

[richard5933]

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.

[TomC]

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