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Old 01-30-2017, 08:47 AM   #21
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boywonder, I purchased groups of used laptop batteries on ebay a year or so ago. Which is a crap shoot to get good ones. Recently I've noticed the prices on ebay have gone to high in my opinion due to everyone trying this stuff. I then cut open the packs to get the cells out. Then tested, etc. It was a lot of work and I wouldn't do it again. I'd just purchase 4 new prismatic/brick cells from the electric car folks. The new brick cells would be safer, ready to go immediately, and in the end not be that much more expensive per KWh. I don't regret starting out with the ebay method because in the beginning I looked at this as a learning exercise with the possible side benefit of working.

Flux, In a way, yes, and that's what you do with all batteries. Voltage and current is your measure of full. The main difference with lithium types is that resistance doesn't really increase as the battery gets full like a lead acid dose. So with lead acid, full is determined by voltage (14.7 ish, varies by battery manufacturer and temperature) and a drop in current below a set amount (say 4 amps, varies by battery size and manufacture). Now with lithium full is mainly determined by voltage only. Since there won't be much increase in resistance once the full voltage is reached you want your charge to stop. Very little to no "float" time is necessary like lead acid and can be damaging. With my pack I chose to end full charge at 4.1 volts instead of 4.2 which is a little lower. With lithium stopping short will increase cycle life which is the opposite for lead acid. Under volting your lead acid will shorten it's cycle life.

1der, Yes temperature is a big limiting factor. There is different info on what is safe for a 18650 cell. Some say do whatever as long as above 0*F, some say it's Ok to discharge below 32*F but not charge, some say storage below 32*F but no charge/discharge. I have my beliefs but I have chosen to be conservative at this time and I keep my pack above freezing at all times. I have it mounted inside to keep it warmer. I have an esbar diesel heater and I don't worry about it running all the time on cold trips to keep the water from freezing too. The heater has been great here in Colorado. I did remove the lithium pack this winter to store it in the garage because the van wont fit in the garage and a lot of mornings here in Colorado the interior van temperature is 32*F or colder. I'm thinking lithium would probably be fine to store below freezing but I'd be concerned charging or discharging. All production packs, EV cars, laptop batteries, phone batteries, have a temperature sensors to cut power when to hot or cold but my home brew set up has no automatic temperature disconnect so it's up to me to decide. Actually a lot of the EV cars have liquid environmental control systems to keep the packs warm and cool for safety and performance.


Here you can see I mounted the battery in the dead space behind the toilet. Not very glamorous but it used up the lost space.


-Eric

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Old 01-30-2017, 08:56 AM   #22
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All great info and well written up.

One of the factors, I believe, with Lithium battery banks is they are not very tolerant of charging at temperatures below 32* F. Right now, sitting here in Beastie3 in Mammoth, it is 27*F, it got down to 5*F this morning.

Our AGM batteries are mounted below and behind the differential, so they see whatever the temp is outside. If I dedicated some room inside, I could have the batteries above 32* while we have the heater on, but I would not be inclined to often leave the heater running while away from the van.

How are you guys dealing with this supposed Li temperature constraint?
We'll have the van heated at all times when away from home. We want fresh water in the winter, so that requires a heated van at all times. We're not doing propane, so our heat will either come from a D2 or Rixen's D5 setup, and we're totally fine having either of those systems running while we're gone. Not a lot of fuel or AH used to power a D2 for 24 hours.

Victron, Mastervolt, and Lithionics all build their own BMS systems that are either built into the battery, or are standalone. They all have low-temp cutoffs in place. So even if you didn't keep the van warm, you can discharge below 32 degrees, but you'd need to wait for the battery to warm up above freezing before it will accept an incoming charge.

Since you have your batteries mounted outside, that really wouldn't work for you unless you went with a custom battery enclosure. Advanced RV has a special box for the batteries mounted in your location, but it's heated, insulated, and has a beefy skid plate on the bottom.

When you factor in the available AH from a cold lead-acid, combined with how fast a lithium can be recharged, most people really don't need much capacity from a lithium battery as far as AH. That means relocating to the interior doesn't take up as much space as one might initially think.

If you figure you have about 80% available from a cold 200 AH lead-acid, that's about 60 AH available (50% depth of discharge). That's 126 lbs of battery.

A 110 AH lithium from Lithionics mounted inside gets you 88 AH available. It's 14.9 x 8.0 x 12.7 and weighs 32 lbs. With a 2nd alternator, you could recharge this battery from empty in about 25 minutes of driving. Compare that to how long it takes to recharge an AGM.
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Old 01-31-2017, 11:55 PM   #23
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WOW!! The education one receives here is priceless! Even when I am barely hanging on the comprehension end...Shuttlepilot, thanks for the easy to understand explanation and tour of your system..beyond cool! Sporty has an inverter, wired for solar (have three 165 watt panels I'm installing when the cold weather leaves Iowa)...we want to stay out for days and not have to use the generator much or even at all if we can...we are power hungry...we have TV (you can see the dome, it didn't look that big when we ordered it! Man that thing is huuuuge, but it makes the general public think we are Govt. or weather chasers), espresso machine, water heater, charging things, toaster oven, furnace, fans, stuff and things...again, I am not even close to your skill level to perform such a feat solo...I am really looking for the plug n play lithium with little to no genius work...BUT, I know we all would want to hear much more about your system and its successes! Again people, all great posts!
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Old 02-01-2017, 07:15 AM   #24
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WOW!! The education one receives here is priceless! Even when I am barely hanging on the comprehension end...Shuttlepilot, thanks for the easy to understand explanation and tour of your system..beyond cool! Sporty has an inverter, wired for solar (have three 165 watt panels I'm installing when the cold weather leaves Iowa)...we want to stay out for days and not have to use the generator much or even at all if we can...we are power hungry...we have TV (you can see the dome, it didn't look that big when we ordered it! Man that thing is huuuuge, but it makes the general public think we are Govt. or weather chasers), espresso machine, water heater, charging things, toaster oven, furnace, fans, stuff and things...again, I am not even close to your skill level to perform such a feat solo...I am really looking for the plug n play lithium with little to no genius work...BUT, I know we all would want to hear much more about your system and its successes! Again people, all great posts!
I think for your situation, there isn't any genius work that needs to be done. Your solar charger would need to be replaced with the lithium version, or updated for lithium. It's the same unit - just with a lithium charge profile. Same with your charger (if it's not adjustable), and maybe your inverter. A quick call to those places will tell you if they are compatible or can be updated for lithium. The wiring and everything is still the same. And the lithium batteries look just like your AGMs. Shuttlepilot went the home-brew route, which is an option for you, but may not be the best option given your knowledge.

Lithionics would probably be a better setup for you given the wide variety of shapes they have, and the fact that they have built-in BMS systems. They are a drop-in physically given that they connect and look just like an AGM. I'm not sure if that's what you meant by plug-in play.

Portable Power and RV Batteries | Lithionics

Remember that you can take a lithium down to 80% depth of discharge, where an AGM is about 50%. So, if you have a 200 Ah lithium, you have 160 usable Ah with lithium, or 100 Ah with AGM.
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Old 02-01-2017, 11:08 AM   #25
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Quote:
Originally Posted by Wrinkledpants View Post
I think for your situation, there isn't any genius work that needs to be done. Your solar charger would need to be replaced with the lithium version, or updated for lithium. It's the same unit - just with a lithium charge profile. Same with your charger (if it's not adjustable), and maybe your inverter. A quick call to those places will tell you if they are compatible or can be updated for lithium. The wiring and everything is still the same. And the lithium batteries look just like your AGMs. Shuttlepilot went the home-brew route, which is an option for you, but may not be the best option given your knowledge.

Lithionics would probably be a better setup for you given the wide variety of shapes they have, and the fact that they have built-in BMS systems. They are a drop-in physically given that they connect and look just like an AGM. I'm not sure if that's what you meant by plug-in play.

Portable Power and RV Batteries | Lithionics

Remember that you can take a lithium down to 80% depth of discharge, where an AGM is about 50%. So, if you have a 200 Ah lithium, you have 160 usable Ah with lithium, or 100 Ah with AGM.

THANKS YOU WRINKLEPANTS!!! That is exactly the explanation/suggestion I was needing...and yes, shuttlepilot (and you WP) have an amazing intel and work abilities...I need the plug n play...and you were correct there too! Just wishing I could "plug the new one in and get to playing as normal." I feel as if I can go back to bed now...I've learned my new 'thing' for the day!
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Old 02-02-2017, 03:11 PM   #26
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After all the great information and education, we have decided to put off Lithium for another lead-acid period...I have the new solar panels to install and will use my current system to recharge/supply electricity...Hopefully, in the time we will use up the next batteries, lithium and its new pieces will be cheaper and a snap to install (I should say, some else to install) Again thanks for the information, and still will call Lithionics to get an idea of what to save up for!
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Old 02-06-2017, 08:00 PM   #27
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Wow, Just now, while reading the latest post in this thread, NBC world news showed home video of a laptop battery exploding while charging. It was then moved outdoors and it exploded again after which a fire extinguisher was used on it. Then it exploded a third time, all while unplugged. The manufacturer recomended charging on a hard surface, disconnecting once fully charged, avoiding rough handling (would 4 wheeling be considered rough handling?) and never to leave a charging battery untended. I think if I were to install one in my van, I'd want it in a fire proof box at the least. The damn thing exploded three times, twice after being unplugged. With millions of these batteries in service all around the world, the chances of it happening to you or me is probably very minimal, but I'd sure want it somewhere where it couldn't catch my van on fire if I turned out to be that one in a million.
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Old 02-06-2017, 08:24 PM   #28
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Laptops are a different chemistry than the deep cycle lithium. It's an apples to oranges comparison.

If you fear being burned alive by a deep cycle lithium battery, then an AGM is definitely the way to go.
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Old 02-06-2017, 09:16 PM   #29
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Laptops are a different chemistry than the deep cycle lithium. It's an apples to oranges comparison. If you fear being burned alive by a deep cycle lithium battery, then an AGM is definitely the way to go.
I didn't know that, but there's no fear here at all, I'm stuck in the dark ages with cheap Costco lead acid golf carts. Shuttlepilot might consider the metal box though, with his recycled laptop batteries. Anyway, I"m not saying I wouldn't love the advantages of Lithium once the price comes down and by that time I expect you will have plenty of experience with them. I"m looking forward to your reports.
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