I have requested a shipping quote for two of those (actually 3 ... to have swap spares):
Post in thread 'What batteries are you using?' https://www.electrifiedboost.com/threads/what-batteries-are-you-using.8/post-348
I'm developing a battery problem...
- Thread starter AlexLTDLX
- Start date
Post in thread 'What batteries are you using?' https://www.electrifiedboost.com/threads/what-batteries-are-you-using.8/post-348
MkngStffAwesome
Active member
i dont think charging C rating really matters cos you'll struggle to charge at even 1c off the alternator.. back to my example of 14s= 51.1v.. 4.5ah @ 4p = 18ah... 51.1v @ 18amps = 919.8watts that at 13v = 70.75amps.... This is the entire current from my alternator and assumes no losses. lol
... if you really want to replicate the TorqAmp with its smart on board charging.
I think for a daily driver we need to find a good combo (motor consumption, battery capacity and charge rate limit, on board smart charging AND a high power charger which takes 220V AC (e.g. limited to 10 A to not trip a standard fuse).
With LTO Cells the fast charging rate really helps for speeding up the charging from a wall socket.
Ideally the battery pack covers some serious time window of operation (realistic, with variable consumption/off times AND alternator support)!
Really trying to wrap my head around "not just track racing".
If a Chevy Volt can operate for a few hours before getting "plugged in" then why can't we design a system which really runs for hours with a itsy bitsy teeny weeny RC motor!?
MkngStffAwesome
Active member
LTO fast charging will not be of any practical benefit.. the example i gave before is at a 1c charge rate and the manufactures spec for the battery says 2c which is your 10A at 220v right there.. we also need to remember than my example is also for a very small battery .. if we took the example form my other post for lifepo4 26650 of 91.25v @ 9p = 42.5ah = 3.878 KW's way more than a 10a 220 system and thats at 1c charging
As for the LTO's it's 89.6v at 18ah = 1.612 kw at 1c .. at 15c charge that is 24.18kws..... Which also isn't possible to charge at 220v 10amps..
LTO's ability to fast change is only useful with smaller packs.
Sure we could have a massive battery capacity (definitely wouldn't be LTO then) to run the the turbo "all the time" but that would result in alot of batteries and expense ... back to my little example... i thing i need about 100amps at 48v...4p gives me 18ah... 23p would give me 103.5ah (322 cells 26650) or 1 hour constant running... in realty on the road or on the track you can't literally run 100% throttle so this could be good for say 2 hour on the track and maybe 3-4 hours on the road (just guessing)
FYI 23P at 51.1v = 5288watts at 1c charging.
Assuming you are on the road and partly (less than 1c) charging from the alternator you really dont need to much capacity because you can not drive flat out for more than 10 seconds .. i mean from 0 how fast will you be going in 10 seconds.. it will defiantly be WAY faster than legal limits.. then after this you probably need to brake... which you can charge... cruzzing charging..... stopped at the lights charging...
I'm defiantly going to be charging from the alternator
As for the LTO's it's 89.6v at 18ah = 1.612 kw at 1c .. at 15c charge that is 24.18kws..... Which also isn't possible to charge at 220v 10amps..
LTO's ability to fast change is only useful with smaller packs.
Sure we could have a massive battery capacity (definitely wouldn't be LTO then) to run the the turbo "all the time" but that would result in alot of batteries and expense ... back to my little example... i thing i need about 100amps at 48v...4p gives me 18ah... 23p would give me 103.5ah (322 cells 26650) or 1 hour constant running... in realty on the road or on the track you can't literally run 100% throttle so this could be good for say 2 hour on the track and maybe 3-4 hours on the road (just guessing)
FYI 23P at 51.1v = 5288watts at 1c charging.
Assuming you are on the road and partly (less than 1c) charging from the alternator you really dont need to much capacity because you can not drive flat out for more than 10 seconds .. i mean from 0 how fast will you be going in 10 seconds.. it will defiantly be WAY faster than legal limits.. then after this you probably need to brake... which you can charge... cruzzing charging..... stopped at the lights charging...
I'm defiantly going to be charging from the alternator
I tend to agree with MSA's points. I do understand that most of you aren't interested in drag strip performance, but you guys have the benefit of having much less displacement to boost. It should be easy to build a pack with sufficient capacity along with an on-board charging solution. MSA and I had a messaging chain where I tested a boost converter. It cost around $20; but the realistic limit for charging a 70 volt pack with one of these is around 5 amps - that gives you 30 amps draw on a 12 volt source. But the toroid got pretty warm; so I'll probably limit the charging current to maybe 4 amps. Either way, at that rate to recharge from 1 dragstrip pass would take about 15 minutes. I could double them up and cut that in half. Interestingly, it's actually more practical to charge from the car's alternator that to plug it in. It's simply easier. You guys could basically do the same thing. Even if you eventually drain the pack, if it's hooked up to only recharge while the main contactor is off, you'd substantially increase your boosted time, probably over what you could use in a reasonable amount of time.
On a completely unrelated (but still battery-related note), I just got in from trying to use one of my Lishen packs to stick weld. The biggest issue? Too much power. I was welding angle iron from bed frames, and was consistently seeing current over 200 amps. For 1/8" thick mild steel, you want to limit current to around 90-100 amps. But the battery stayed completely cold, and in fact after over 10 minutes of screwing around the voltage in the pack dropped less than a tenth of a volt. Talk about some insane power! And to think, I'm using two of these packs in series...
On a completely unrelated (but still battery-related note), I just got in from trying to use one of my Lishen packs to stick weld. The biggest issue? Too much power. I was welding angle iron from bed frames, and was consistently seeing current over 200 amps. For 1/8" thick mild steel, you want to limit current to around 90-100 amps. But the battery stayed completely cold, and in fact after over 10 minutes of screwing around the voltage in the pack dropped less than a tenth of a volt. Talk about some insane power! And to think, I'm using two of these packs in series...
MkngStffAwesome
Active member
My example of 18ah .. with 100amps pulled gives me 10.9 minutes of run time .. lets call it 10minutes... but remember that's 10 minutes of constant draw... this sounds like nothing but it's actually alot that is 60 10 seconds runs without charging !, I would be in jail for long time if it did that ! lol
Obviously as long as there is some charging going on too then the numbers will increase..
If i charge at 5amps then it will take 20 times longer to charge than discharge.. so a 10 second run would take 200 seconds to charge... this also sounds bad but thats less than 2 minutes,, and this is for an impractical 10 seconds run that maybe you'll do every now and again.. and also as their is a 200 second gap you can do this endlessly.
There is the situation where say there is a big hill and maybe you want to boost up that .. sure you can do that for 5 to 10 minutes (thought not constantly because you will need to turn and brake as some point)... presumably you'll have to go down the other side so wont be boosting for that.. so as long as it's off 20 times more than on then your all good. Which as long as it's not on at cruse speeds you'll be all good.
i'd like to also say that his is also true for real turbos,, while a turbo can in theory run max boost for ever ... driving conditions does not allow that.
Obviously as long as there is some charging going on too then the numbers will increase..
If i charge at 5amps then it will take 20 times longer to charge than discharge.. so a 10 second run would take 200 seconds to charge... this also sounds bad but thats less than 2 minutes,, and this is for an impractical 10 seconds run that maybe you'll do every now and again.. and also as their is a 200 second gap you can do this endlessly.
There is the situation where say there is a big hill and maybe you want to boost up that .. sure you can do that for 5 to 10 minutes (thought not constantly because you will need to turn and brake as some point)... presumably you'll have to go down the other side so wont be boosting for that.. so as long as it's off 20 times more than on then your all good. Which as long as it's not on at cruse speeds you'll be all good.
i'd like to also say that his is also true for real turbos,, while a turbo can in theory run max boost for ever ... driving conditions does not allow that.
WB projects
Active member
@AlexLTDLX @MkngStffAwesome I just post something and my charging onboard is awesome ! sorry I dont take the time to read all your text but Im doing it right now haha
sorry if you got me wrong. I am very well aware about the realistic "duty cycles" of boost (configurable for sure as well).
And I am aware about the realistic gains with alternator charging in the pauses (what I called on board charging).
I was just promoting the wall plug charger ADDITIONALLY ... (even if it won't be on higher Cs and for safety reasons).
Thinking of having the car parked at night ... and plugged to the wall ... just to make sure everything is full next morning. (Well yeah, DIY LiPo is out of the game for me just for the recharge risks! EV LiPo modules which are able to deliver the current are not cheap either!)
And I am aware about the realistic gains with alternator charging in the pauses (what I called on board charging).
I was just promoting the wall plug charger ADDITIONALLY ... (even if it won't be on higher Cs and for safety reasons).
Thinking of having the car parked at night ... and plugged to the wall ... just to make sure everything is full next morning. (Well yeah, DIY LiPo is out of the game for me just for the recharge risks! EV LiPo modules which are able to deliver the current are not cheap either!)
MkngStffAwesome
Active member
You made this statement
So we explored the truth of LTO's faster changing (15c) being useful or not relative to lifepo4(1-2c)... Which is.. theoretically yes .. but in realty no.
You then made this statement
I then Explored that statement..
I'm not trying to be a know it all...
I didn't actually know the answers until i started to run the numbers ... I wanted to run the numbers because i need to know the answer for myself too.
People are making statements.. here and there and they are interesting statements ... And they should be investigated for the good of everyone.
So we explored the truth of LTO's faster changing (15c) being useful or not relative to lifepo4(1-2c)... Which is.. theoretically yes .. but in realty no.
You then made this statement
I then Explored that statement..
I'm not trying to be a know it all...
I didn't actually know the answers until i started to run the numbers ... I wanted to run the numbers because i need to know the answer for myself too.
People are making statements.. here and there and they are interesting statements ... And they should be investigated for the good of everyone.