House battery bank

[buswarrior]

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

[richard5933]

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.

[chessie4905]

Brushless motor?

[Dave5Cs]

no spark condition I hope.

[richard5933]

The fan is specifically designed for this application. Used in many solar installations around the world. Not worried about sparks.

http://zephyrvent.com/

[chessie4905]

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.

[richard5933]

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.

[Oonrahnjay]

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

       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

[MagnoliaBus]

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 !

[MagnoliaBus]

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 ?

[richard5933]

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.

[TomC]

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

[richard5933]

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.

[eagle19952]

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.

[MagnoliaBus]

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).