Who has experience with (blue) aluminum cells in a mobile system?

[Mex Rider]

BTW, don't forget, if you are building or modifying use only dual contact power points in an RV of any sort, and don't forget to add an RCD if you don't already have one installed, better broke than dead. I also added a changeover switch.

For us beginners, or me at least, what is a RCD and what are dual contact power points? Thanks for the help.

 

[Mex Rider]

No website. We sail the west coast of BC so very rugged, very remote at times and lots of storms and adverse weather, Baba 30, loaded with solar, wind gen, hot pressure water, water maker etc. a solid boat for a semiretired couple in 50's. do 1-2 month trips with friends with their own boat every spring/summer. Sailing for 30 years on west coast Canada

Last boat, before serious health issue was Tradewind 35 with 400 amp hours of AGM....so much weight for my little boat....If I had only known about lithium, lol! Building a cruising van to take its place, easier to get to medical when needed but most all of the same design parameters, thinking about portable watermaker given the impending climate catastrophe, sadly to say. One of my four liveaboards over twenty years was a Baba40.... oh how I loved that boat. Keep sailing amigo, wind and seas at your back.

 

[sduser]

can I hook up all eight cells in parallel and just wait for them to equalize?

Yes but it could take a long time.

See 1:35 here

 

[Scott Sparks]

Hello everyone, new to the forum. Seems like lots of good information here. I have a Class A 30' motorhome. I've installed 8 100watt panels on the roof in series parallel due to concerns of shadows out dry camping. I've found some 4awg PV cable that I used to connect the panels and feed down to two Tracer 4215BN MPPT Charge Controllers monitored with two MT50 meters. This gives me some added capacity if I decide to add more panels. These feed my battery bank which is currently 896Ah(8x 224Ah 6v) of AGM batteries. This feeds a Xantrex 3012 inverter charger which I was lucky enough to pick up refurbished. I just purchased 16 135Ah lifePO4 AL cells from BLS to replace the very heavy AGM batteries. My plan is to 3D print a quarter inch spacer insert between each cell to provide an air path between the batteries to help cooling. Then construct two rings around the batteries, one near the top and one near the bottom. Then mount on a plywood board with holes drilled for cooling. then mount this on some type of form cushion or spring arrangement for some shock mounting. I will post any issues I see along the way. My main concern is cooling and vibration, when we are plugged into shore power or running the generator the inverter can pump out up to 150A for charging the batteries. So if they are depleted this could cause some heating and heat is a big battery killer as is vibration. I plan on installing a temp sensor on each battery, you can get these small temp sensors on Amazon that have two sensors per display and you can run the sensor leads on stranded CAT5 or CAT6 wires so you can get 4 sensors connected with one cable. These can then be brought inside to an instrument panel. I realize it's probably a little over kill but I'd rather have too much information than not enough.

 

[Tex]

THE ENGINEER. An engineer is a person who passes as an exacting expert, on the basis of being able to turn out with prolific fortitude, infinite strings of incomprehensible formulae, calculated with micro-metric precision from vague assumptions which were based on debatable figures taken from inconclusive experiments carried out with instruments of problematical accuracy by persons of doubtful reliability for the avowed purpose of annoying and confounding a hopelessly bewildered group of practical, mechanically minded and experienced personnel who are frequently referred to as the "Shop".

Bit harsh!
Twelve months ago I couldn't even spel enginear, now I are one!

 

[Tex]

Yes but it could take a long time.

See 1:35 here

I find my ISDT BatteryGO-8S to be be very efficient for the price, can take a day or two.
Good for top or bottom balance

.

 

[Mex Rider]

Yes but it could take a long time.

See 1:35 here

Thanks, looks like I'll need to order a capacity tester, problem is lockdown here in my little town.... can't return if you leave except for doctor

 

[Dzl]

For us beginners, or me at least, what is a RCD and what are dual contact power points? Thanks for the help.

Not sure if this got answered already or if I'm even correct, but I believe an RCD is similar or identical to a GFPD (Ground Fault Protection Device)

 

[Mex Rider]

Okay...have not seen that mentioned before, and fo you know what dual contact power points are...thanks much

 

[Ampster]

I find my ISDT BatteryGO-8S to be be very efficient for the price,

The setting on your BMS is for Lipo not Life. Your voltages look like Life (LFP or LiFePO4)
I apologize if this is redundant, I recently saw a similar comment in another thread but couldn't find it. I wanted to let you know before something bad happens. Presumably your charge controller is set for the correct chemistry, which should reduce the probability of anything happening.

 

[grizzzman]

The setting on your BMS is for Lipo not Life. Your voltages look like Life (LFP or LiFePO4)
I apologize if this is redundant, I recently saw a similar comment in another thread but couldn't find it. I wanted to let you know before something bad happens. Presumably your charge controller is set for the correct chemistry, which should reduce the probability of anything happening.

I agree the PIC is shown as Lipo not Life. I used one early on.(still have it collecting dust in a box)

 

[Zil]

Bit harsh!
Twelve months ago I couldn't even spel enginear, now I are one!

This was copied from a wall posting in the first Tool and Die, Job Shop I worked. Beautifully hand lettered as a practice lettering assignment from 1910.

 

[Mex Rider]

I find my ISDT BatteryGO-8S to be be very efficient for the price, can take a day or two.
Good for top or bottom balance

.View attachment 17355

What I need, and just ordered is a capacity tester, but to your monitor suggestion, do I need that if I am using a BMS with every cell monitored? I guess I still need this for the setup used in conjunction with the capacity tester.

 

[Tex]

Not sure if this got answered already or if I'm even correct, but I believe an RCD is similar or identical to a GFPD (Ground Fault Protection Device)

Yep, exactly. residual current Device.

 

[Tex]

Okay...have not seen that mentioned before, any of you know what dual contact power points are...thanks much

Double pole GPO/Powerpoint/mains power outlet switches both the active and the neutral, because of the ground situation in a van or boat, if someone reverses the active and neutral in a plug you could still have a live outlet. Legally mandatory in Australia at least, as are double pole RCD's.

 

[Tex]

The setting on your BMS is for Lipo not Life. Your voltages look like Life (LFP or LiFePO4)
I apologize if this is redundant, I recently saw a similar comment in another thread but couldn't find it. I wanted to let you know before something bad happens. Presumably your charge controller is set for the correct chemistry, which should reduce the probability of anything happening.

Sorry for the confusion, that ISDT BatteryGO-8S is nothing to do with my BMS, it is just a plugin balancer for occasional use or checking, it doesn't care what the battery chemistry is, it just performs a simple cell balance. I wired the leads in alongside the BMS balance leads, and it terminates in a plug. The Beauty of it is I can plug it in any time and check the numbers against what I am getting from any of the other connected devices, (BMV-712, MPPT75/15 etc. Or I can perform a top or bottom balance independently of the BMS or anything else if required, (takes a couple of days).

You can see all of my Victron settings in post #101 (see attachments below), I am still waiting for opinions from anyone as to their correctness or otherwise.

 

[Mex Rider]

Double pole GPO/Powerpoint/mains power outlet switches both the active and the neutral, because of the ground situation in a van or boat, if someone reverses the active and neutral in a plug you could still have a live outlet. Legally mandatory in Australia at least, as are double pole RCD's.

Thanks, will have to investigate this equipment in the U.S....haven't seen it mentioned before

 

[sduser]

I am considering using 8 of these 105Ah cells from @mkpieters in a 2P4S configuration. Normal usage would be low (0.1 C) charge/discharge rates. I would like to be able to use as a vehicle starting battery in an emergency though (bypassing the BMS and connecting jumper cables directly to the battery terminals. Any thoughts on the quality of these cells? Specs look good but my biggest concern is the M4 terminals with max torque of 8Nm. Thoughts on these securing larger busbars and pushing 2C-3C?

135Ah LifePO4 cells for sale

diysolarforum.com

 

[redmessengerbag]

Hi Guys, In regard to LiFePO4 batteries in RV's I can provide the following advice.

Cheers
Tex

Without completely quoting the entire post, I wanted to quote Tex's post from first page with the images of his cells in the foam shippers.

How much ventilation does the cells need? After reading this thread, I am a bit nervous now and really like the idea of using the foam the batteries were shipped to me in as to protect against vibrations and flying banging around. But it seems that it would eave very little ventilation especially if the top is closed (Planning a plastic battery box or plywood box)

This is going into an "off-road" van. It's a 4WD ford E350, we are not doing any rock crawling but will be doing some trails...I bought the 280ah xuba cells, and will report back how well they hold up.

 

[Dzl]

Without completely quoting the entire post, I wanted to quote Tex's post from first page with the images of his cells in the foam shippers.

How much ventilation does the cells need? After reading this thread, I am a bit nervous now and really like the idea of using the foam the batteries were shipped to me in as to protect against vibrations and flying banging around. But it seems that it would eave very little ventilation especially if the top is closed (Planning a plastic battery box or plywood box)

This is going into an "off-road" van. It's a 4WD ford E350, we are not doing any rock crawling but will be doing some trails...I bought the 280ah xuba cells, and will report back how well they hold up.

This is still a somewhat open question in my book, but from the data I've seen, compression should take precedent over ventilation unless you will be using high C-rates. From what I've read, cell temperatures will be within a few degrees of ambient up to roughly 0.5C, start to become a factor around 1C and above. This data comes from a study of 20 Ah cells. 280 Ah are a hell of a lot bigger, so I'm not sure how directly it applies, but I would think the principle shoudl be the same (low C-rate = minimal heat generation).

If you compare to drop-in lithium batteries they are completely sealed, packed in, and self contained, (usually with a BMS inside generating heat) and seem to be fine up to 1C. This point is just speculation, I'm not sure how comparable it is.