[bikestuff]

Gurus,

This is the first post of my experiences with the Battleborn lithium batteries.  I'll start with conclusion and then share some of the experiences in getting them going.

I like em.  (at least so far).  I ordered 6 of the BB10012 batteries.  They are roughly the size of a regular car battery.  They are far, far lighter than the old AGM batteries.  In fact, I shed 1200 lbs in batteries by doing the switch.  They seem to be constructed well and one call to technical support makes me think this business is serious.   I have not dry camped with them so I don't know how they will really work....but that is for another post.

First Attempt...

When I was at the No-rally-rally, I got some buddies together and we took out the old batts and reinstalled the lithiums using the old cables.  It all seemed to go together pretty well, but when it came time to test them, my Magnum charger was putting out crazy voltages (80-120VAC)!  It was really weird.  I did not have time to troubleshoot before heading home.

When I got back home, I disconnected all but one battery.  With one battery installed the inverter still was acting up.  I called Magnum and talked to their technical support.  They were very good, but they were also pretty cavalier with their safety protocols. I will tell you about that in a second.  They suggested that the inverter had a bad AC board...whatever that is.   I found a great company Inverter Service Center who offered to either repair old one for around $500 / two weeks, or send me a new one $1800 / overnight.  I opted to get a new one and will send old one back at my leisure.

Part of the troubleshooting with Magnum involved disconnecting the AC out wires from the inverter.  I did that without incident...but when I went to put the AC wires back I got a nasty shock.   Here is what you have to realize about the inverter.  It is a pass thru when it is not inverting. (It has its own transfer switch)  The power to your fridge, 120V air compressor and other stuff that runs when your are on batteries goes through the inverter.  I did not fully grasp that fact until I got bit.  

Second Attempt.....

After the first attempt I knew a lot more about what I was doing.  Making new cables was a necessity because the batteries are far different in form factor.  Also the old cables were .....what is the word?.....oh yeah....OLD!  So I sent off and got 50' of black and 50' of red boat cable.   All of it was 4/0 gauge.   This is much higher quality than was came in the coach.  Each cable is made up of lots of little copper wires, but with boat cable, the wires are tinned so that they resist corrosion better than plain copper.  Of course, I had to get a bunch of lugs and a Crimper.   I also got some Heat Shrink Tubing to seal the cable jacket to the lug.

About lugs....there are a million sizes.  You have to get lugs made for your size cable...then you have to make sure the hole is the right size.  On the coach there are some 3/8 posts and some 5/16 posts.  You will need some of both.  

Loaded up with supplies I made a second attempt.  I gently removed the top shelf of my battery rack.  And by gently removed, I really mean absolutely destroyed.  This gave me much more room to work.   3/4" plywood went into the bottom of the shelf to hold the batts.   The batts were wired together with newly made cables. 

In my coach, the positive 12VDC goes to two places...One a lug mounted high up in the bay.  It has two cables on it...one goes to the Isolator in the engine electrical bay and the other goes to the front 12VDC distribution panel in front of passenger seat.  The other 12VDC cable goes directly to the inverter.  While I have a shutoff in the ground wire going to inverter, I did not have a way of shutting off the 12VDC positive....so I added a switch.  I also added a switch to the the wire going to the lug so I could cut off the rest of the 12V positives.

After I got the batteries wired up...time to replace the inverter.

That sucker is heavy!  Disconnecting the wires was easy.  (I turned off the breaker to the inverter, and also used my fancy new switch).  Checking for voltages with a voltmeter is essential.  Do it again, and again to make darn sure there is no voltage present on any leg.  (12VDC and 120VAC).

I built a little stack of plywood to help move around the inverters.  That worked really well.  Got it mounted and the wires reinstalled.  

IF YOU READ NOTHING ELSE ...READ THE FOLLOWING.

The Magnum charger has a very specific start up sequence.  Get the manual and read it three times!   I am pretty sure I killed my original inverter by not following the instructions.   The manual calls for you to leave the AC power off, until you have verified the DC inverting function.  After that you can test with AC.    YOU CANNOT MODIFY WIRES WITH EITHER 12VDC or 120VDC APPLIED.

After the start up procedure the inverter was making 120VAC from the batts and was generating 120VAC pass thru when the shore power was connected.  So all is well.

Conclusion
My old batteries were at the end of their life so it was a no brainer to replace with lithiums.  Battleborn seems like a good company.  I am very happy that I replaced the old cables.  I am not so happy I had to replace the inverter.....expen$ive lesson.

I will report as to how they work in the real world after I have some more experience.

Thanks to Forest and Richard for giving my insight along the way.  Also thank you Georg Ohm for your law.  

Cheers,
bill

[bikestuff]

Gurus, The diagram in the first post is a little misleading. I actually did not install the shunt yet....it is part of the Magnum state-of-charge system. It goes in the negative lead...right after battery before anything else. Also, the fuse should be installed in the positive 12VDC side before anything else. Magnum recommends a 250 amp fuse.

Don't blindly follow anything I say.....You should spend some time with Georg Ohm before you try this at home!

bill

[smagown]

Great update, Bill.

[pairodice]

Thanks for the post on the lithium install! I would love to do this (not sure why though!)...
It looks like you have enough space left over for another slide out tray for stuff.
Are you using them for the engine also?
Nice drawing btw! I started building one and then got sidetracked on other things (squirrel!)...

[bikestuff]

Adrian,

The Battleborn batteries are specifically NOT for engine use. (According to Battleborn). I am not sure why. I replaced my engine batts last year (Lifeline AGM) so I did not even consider lithium’s for this use.

Bill

[bikestuff]

Gurus,

I am adding to this thread as I learn things about the new lithium’s.

As you may know, lithium batteries are really, really good at providing their rated voltage until nearly depleated of charge.   The red line is regular batteries and the black line is lithium.  Notice how much more horizontal the red lines stay.  

   

That is really good.   

But..... (and with me you always know there is a but coming)

How does the charger (in my case a Magnum 2812) know when to start charging the batteries?

I ran the batteries overnight with about a 12-25 amp draw.  When I went to bed I had a DC voltage of 13.1 volts and when I woke up I had a DCV of 13.1. It was hot and I cranked the generator.  The display on the Magnum says Float Charging, but 0 AMPS!  This means there is no current going into the batts.  What gives?

It turns out that the Magnum was built expecting to see a gentle roll off of voltage (red line) and when it gets below 12.8VDC it starts the four step charging process (Bulk, Absorb, Float, Full).

Since I am at 13.1VDC the charger thinks that I don’t need to charge and it is right.  

Here is the thing with lithium technology.  It gives that nice flat voltage right til the end (black line).  Then it falls like a knife!  It seems as though I will not be able to charge the batteries unless they are almost fully discharged.  I am not sure how I feel about that.  

I have a State of Charge accessory from Magnum that I will hook up this week, but the charger does not use SOC as part of its algorithm...it only uses voltage.  (According to the manual).

I am gonna run the generator today.  Tonight, I will turn off genny and monitor battery voltages.   

Cheers,
Bill

[folivier]

Hmmm, my older Freedom 2800 floats at about 13.4Vdc and will do a variable float charge of a few amps to keep my BBs charged. But I did have to look at their chart and select flooded lead acid as the battery type and warm as temperature environment. That gave me the float value of 13.4Vdc. You might have to do something similar to trick it to give you the values you need. Oh, did you disconnect or turn off the temperature compensation on your Magnum? By setting the temp. that allows the charging values to stay the same.
Ours are working great!

[bikestuff]

Forest,

I can adjust the float value in the remote and it is set to 13.3VDC right now. The remote says its in Float Charging mode.

According to Magnum....

Float charge happens after Absorb charge and lasts for four hours after that the system enters FULL charge. It will remain in full charge until the battery voltage drops below 12.7 volts, when it will enter float charge state again. [Note: the knee of the curve when the battery is at the end of its charge-life is at 12.5VDC which is really close to the fixed 12.7VDC]

If the battery voltage falls below the 12.1VDC it will enter the Bulk charge state.

So, if my Magnum is set for 13.3VDC float voltage, and the “re-float” voltage is 12.7VDC (fixed), the system should bounce between those two values.

Here is simplified state diagram of charging for Magnum / Battleborn
Bat voltage. State. Note
====================
12.1 V Bulk. Until Absorb charge is achieved. (14.4VDC)
14.4 V Absorb. Adjustable time based on Ampere Hour rating of battery bank
13.3 V Float. Adjustable voltage. Lasts for 4 hours
13.3 V Full. Stays in Full until voltage drops to 12.7
12.7 V Float. Adjustable voltage. Lasts for 4 hours.
13.3 V Full. Stays in Full until voltage drops to 12.7

...

I will talk to Battleborn / Magnum and see what they say.

Thanks for your help!

[bikestuff]

So the Battleborn batteries are 100Amp-hour capacity.

This means that they can supply 100 Amps for an hour.  With 6 batteries they can supply 600 Amps DC for an hour.  

There are a couple of advantages for lithium batteries.  They don’t mind how you use the amps.  You can pull all 600 amps quickly or over a longer period of time.   With lead-acid batteries there is a penalty for pulling the amps too quickly, you will not get the rated amp-hour of the battery.  Also, lead-acid batteries will be damaged if you EVER pull more than 50% of their charge.

Richard says batteries never die, they are murdered.   This is the reason...if you pull your batteries below a 50% charge, you are eating into their expected life.

So...in my case, I went to bed at 11:00pm with fully charged batteries and a worst case 25amp draw.  I woke up at 6:30.  That is 7.5 hours x 25 amps = 187.5 amp hours.  So, overnight with no particular power conservation I used 31% of my capacity.    If I turned off a few things, the current draw would be 13 amps -> 16% capacity used overnight.

Food for thought.

[Richard]

I don’t know what your charging strategy will end up being. I am aware that using the float mode in conjunction with the flat discharge slope, doesn’t put the charger into a real charge mode until the batteries are pretty depleted. While plugged in to a pedestal, that isn’t an issue at all.

But, if I know I am going to boonie overnight or longer, I simply tell the Magnum to charge. Press the CTRL button, rotate the dial one notch, press the dial, you now can toggle between float and bulk. Toggle to bulk and press the dial. This is my way of ensuring a fully charged battery.