Lead acid battery conversion to lipo

[cgtech]

I used a cleanpowerauto SOC/info meter on those rxvs on that other thread, they work great, and fit in the stock dash no cutting or mods. There are no T-105s in this area for less than $8-900 a set of 6. Another great resource about everything battery look up www.batteryuniversity.com . But, beware, its a 100+ page book on a website, you might get stuck there all day.

[scottyb]

Lipo has some drawbacks, mainly the fire hazard already mentioned. They were popular in the RC industry where their spontaneous combustion is legendary. Proper handling makes them reasonably safe - but its the uncontrolled variable I worry about.
Lipo is being replaced by Lifepo technology. It's safer, charges safely at a much higher rate and has a much lower self discharge rate. I think given a little time the cars will adopt this technology.
Lead acid batteries have been the heart n soul of the electric cart since the 1950s. I don't think lipo is the technology that will replace it.

Keep us posted.

[Rickochet]

Here is a link from RCGroups forum for their Batteries and Chargers sub forum. Lipos have been very popular in RC aircraft for years. But you have to know exactly what and what not to do. Even a small lipo pack can explode with quite a force. Good luck and be careful. This is not the scale you are dealing with but there might be some info you can glean from it.

http://www.rcgroups.com/batteries-and-chargers-129/

[Toplsvette]

Originally Posted by scottyb

Lipo has some drawbacks, mainly the fire hazard already mentioned. They were popular in the RC industry where their spontaneous combustion is legendary. Proper handling makes them reasonably safe - but its the uncontrolled variable I worry about.
Lipo is being replaced by Lifepo technology. It's safer, charges safely at a much higher rate and has a much lower self discharge rate. I think given a little time the cars will adopt this technology.
Lead acid batteries have been the heart n soul of the electric cart since the 1950s. I don't think lipo is the technology that will replace it.

Keep us posted.

Scotty, I don't think lipo will replace lead acid anytime soon either. I just like to try new stuff out. My brother is a mechanical engineer with Bosch that developes battery packs for electric cars and he is helping me some to make sure I do things right. The prismatic cells I am going to use are Lithium Nickel Manganese Cobalt Oxide. They are newer than the lifep04 cells. These cells are used in the Nissan leaf electric cars. With a proper bms that senses voltage and temp they should be safe to use.

[Toplsvette]

Originally Posted by sportcoupe

My local golf cart shop sells new Trojan T105's for $620. It's hard to believe your lithium cells and BMS are cheaper then that even if you are using tiny AH cells.

You won't find t-105's for $620 here in Florida where I live.
I am able to buy a 7.6v 60ah module for $109. For a 36 volt pack requires 5.
They are sold by hybrid auto center. Clean auto sells a mini bms for what I am doing for $106. So it is close to a set of t-105's. We can't get t-105's for less than $700+ here.

[cgtech]

Originally Posted by Toplsvette

Scotty, I don't think lipo will replace lead acid anytime soon either. I just like to try new stuff out. My brother is a mechanical engineer with Bosch that developes battery packs for electric cars and he is helping me some to make sure I do things right. The prismatic cells I am going to use are Lithium Nickel Manganese Cobalt Oxide. They are newer than the lifep04 cells. These cells are used in the Nissan leaf electric cars. With a proper bms that senses voltage and temp they should be safe to use.

This is how i feel too (although, i think in 10-15 years they may be far more common). Every time the lithium topic comes up, there are always a few "negative nancys" who say 'nooo', or 'too expensive', or 'unproven', or 'i like cleaning acid and corrosion', i made up that last one. When the idea was proposed to build the niagra falls hydropower plant to electrify new york city, im sure the same "negative nancys" were there too. If we are ever going to progress into newer, better things, someone has to jump in. I'm excited to be able to participate in setting these things up, Plus i get paid to do it! In my spare time, i enjoy building electronics, and all things mechanical, i would be doing this kind of stuff anyway. When i was a kid, nothing electronic better sit too long, or i was "pirating" it for parts, and a 4 speed trans in my yard i had disassembled was always an interesting distraction.

Toplsvette, looks like you have some good people around you to help with any info you nay need.

[Toplsvette]

Cgtech,
I am the same way. When I was growing up I had to take everything apart to see how it worked. I am a retired USAF fighter mechanic and love tinkering with things. I can build or fix just about anything. My grandpa was a machinist and my uncles were professional drag racers and I hung around them a lot. So I ended up with my grandpas metal lathe and machine tools. I am building a 1940 Chevy pro street truck and a 29 ford model a 4 dr sedan cruiser. I just love building things. I ordered the modules and bms today to give it a shot. I am making a 48v pack for it. Motor is out and ready to send off to plum quick Monday. Do you recommend a 48v solenoid for it. I can reprogram the alltrax for 48v. Is there anything else I am missing. I know I need a charger but there is plenty out there.

[Volt_Ampere]

Look at it this way. If Lipo batteries were ready for prime time they would be standard equipment in golf carts. If electric cars were ready for prime time we would all have them. I worked on electric cars back in the early 70's. They were not practical then or now. More so now but not there yet. I am not talking Hybrids here but full electric only.

[sportcoupe]

It LiPo's aren't good enough for fully electric cars (Tesla Model S has 265 mile range) then FLA batteries aren't really good enough for a golf cart (20-30 mile range).

Then again if it suits your needs (golf cart 2 rounds golf or Tesla Model S anywhere in town for a week) then it is viable.

To compare, a 1908 Ford Model T had top speed of 45 mph and 20-30 mile range. It was gas powered. Good thing we didn't give up on gasoline as a power source.

[cgtech]

Funny thing Toplsvette, my dad was a machinist too, i unfortunately didn't get the lathe... Looks like you got some sweet iron loitering in your driveway!

And yes definitely get a 48v solenoid, Scottyb Www.cartsunlimited.com has good deals on heavy duty ones, and nice cables. You are also going to want at minimum 2ga cables everywhere. If you choose to make your own to link the cells, use only high quality welding cable like Exelene or similar, none of that crummy standard auto battery cable stuff.