Category Archives: Parades

Watch me build a new battery / inverter box!

I thought it would be fun to have you tag along as I put together my fourth battery / inverter system.

My current battery rigs work incredibly well … But are too heavy to get in and out of my truck with two people.

I’m hoping that a smaller, modular approach will work. The idea of having a box of batteries that could be used by itself for smaller events … But could also be plugged into a larger system for larger events is very intriguing.

I had an old amp rack sitting around that I decided to try out as a battery system. It was a well made case that I had the good luck of not being able to sell on e-bay … And with this year’s Dance for World Community adding another stage to power I decided to give it a try.

The case turned out to be an almost perfect fit for four group 31 AGM batteries … A total of about 5 kWh of power if I’m doing the math correctly … I only plan on using about half of that in an attempt to keep the batteries working in top shape for as long as possible.

The case was made of 1/2″ luan plywood with some sort of plastic laminate covering, all held together with very heavy duty aluminum extrusion … It was built like a tank!

My biggest question … Would the case be able to handle all that weight?

The case did make it a lot easier to wire up the batteries and inverter. The removeable front and rear covers were now going to be the top and bottom, with the main body of the rack becoming the walls of the battery pack.

Four Group 31 AGM batteries installed on back cover of amp rack

Four Group 31 AGM batteries installed on back cover of amp rack

The former rear cover had a nice set of casters mounted on a Baltic birch caster plate … And with the addition of a 3/4″ birch “sub floor”, a layer of KYDEX and another 3/4″ “collar” around the batteries it looked like a good place to start.

The next step was to figure out how best to wire the batteries to the inverter.

A circuit breaker and fuse are added to keep things safe and a metering system is added to keep an eye on how the batteries are doing.

Wiring layout for the new battery / inverter box

Wiring layout for the new battery / inverter box

Here I have the two panels I will be using with the buss bars, fuse holder, shunt and circuit breaker mounted on them. Adhesive backed shrink tubing will be added over the crimped on lugs for safety … and to help protect the wire from corrosion.

I am using 00 marine grade wire for the interconnecting all the parts and I will be using #2 marine grade wire to connect the 12 volt batteries to the bus bars.

It is very important to use the right size wire when working with low voltage DC. The general rule of thumb is to use the largest, shortest wire you can … Otherwise the resistance in the wire will rob you of too much power.

I am already thinking of swapping out the #2 cable for #1 … We’ll see!

Eventually I will be adding a 350 amp ANDERSON SB connector to the pack (to connect multiple packs together) and have included an “extra” set of buss bars to make it easier to do when the time comes.

The AGM batteries I am using are supposed to be safe to mount in any position … And I suspect someday someone will tip this case on end to get it off of it’s wheels. I’m curious to see how the spacers hold up under that!

I've added spacers between the batteries to hopefully keep everything in place should someone ever tries to test the

I’ve added spacers between the batteries to hopefully keep everything in place should someone ever tries to test the “mount in any position” feature of the AGM batteries!

A top “deck” will be mounted on the two power panels for the inverter, battery meter and the ANDERSON SB connectors.

A little paint and it’s time for the “final” assembly.

Wiring of the

Wiring of the “positive” side off the battery bank

I like the modular approach of this system a lot … Making changes as I learn will be a lot easier … In theory!

Having this kind of access to all of the connectors was wonderful … You should have seen (heard?) me trying to wire my previous rigs!

Almost done ... Just need to add the cover and a fan!

Almost done … Just need to add the cover and a fan!

Shrink tubing added … Circuit breaker and fuses installed … Notice the “trap door” for getting at them … as well as the 175 amp ANDERSON SB connector for plugging into my chargers.

With the cover closed up and the fan on the system has been working wonderfully.  The next step will be to add the 350 amp  connector and assemble a larger inverter / power distribution system.

A great project for this winter … Will keep you posted!

Ready to go to work! Trimetric 2035 battery meter on the top left ...

Ready to go to work! Trimetric 2035 battery meter on the top left, “Kill-A-Watt meter to it’s right and 1,100 watt sine wave inverter and the connector for plugging into my  60 amp solar charge controller below.

Luck of the “Irish”!

In the mean time … The show must go on … The rewiring project was going to have to wait.

3/17/2013 … If you live in Boston that date can only mean one thing …

The South Boston St. Patricks Day Parade … Where being Irish is not really required!

I got a call from Mike Majorowski wondering if my battery system would be able to power a float for his band in the parade.

Hmmmmm…..

To see if it could be done I set him up with a couple of “Kill-A-Watt meters to use at his next gig to see how much power they would need … While I started to worry about the weather. Rumor has it that batteries do not like the cold!

With the readings he got from the “Kill-A-Watt meters It looked like my smaller battery system would do the job … At least if the weather co-operated and we got that perfect 77 degree day the batteries were rated for (this is Boston … and I’ve shoveled snow in May!)

I explained my “concerns” to Mike and we decided to try the parade using my larger system … At the smaller system’s price.

We had a beautiful sunny day for the parade … If you don’t mind a little cold wind … We started sound check at 10:00 am at 28 degrees And got all the way up to a “balmy” 37 degrees somewhere along the parade route!

Five hours of run time, 1.83 kWh of power used … We even got a nice “Cool!” From the Boston Police Truck team inspecting all the floats when they asked where we were getting our power from … apparently we did not need a special permit for using a generator on the float … Cool indeed!

At the end of the day the inverter battery meters still showed 90 – 100% full … It would have been nice to have the new meters installed … The parts had arrived … the extra time needed to install them was still on back order!

It was my first event moving the battery boxes around by myself and one thing was certain … Those battery boxes are heavy … Very heavy!

The larger battery system with the Trimetric 2025 meters installed

The larger battery system with the Trimetric 2025 meters installed

The larger system consists of a pair of “Site Safe” tool boxes with each box weighing in at about 500 pounds! … So “portable” is a relative term!

Moving them from the truck to a loading dock, or in this case … To the back of the “roll off” tow truck that was used for the float was pretty easy … Pushing them up the ramp to my truck? … Not so much!

Moving them around was going to take three or four people … Or a lift gate on the back of the truck … I will need to figure that one out later …

My to do list keeps growing!