Had it with Hobbyking products..

[sn0wchyld]

Guys....paying £120 for a poxy 120watt charger for Lipo in Uk is crazy. I have to charge 17Ah of 66V Lipo and I got fed up very quickly of using a normal RC Charger.

So I bought a standard KP charger, you can get the 600W ones for $73 plus deliver from most places like http://www.bmsbattery.com/alloy-shell/27-alloy-shell-600w-lifepo4li-ionlead-acid-battery-ebike-charger.html

Just get them to adjust it so that it charges to you packs total i.e Cells x 4.15v and bulk charge it. The .5V headroom will stop any sneaky overcharging of cells and give you longer life of the lipo. Then I use a stand alone balancer that once a week I just leave on the series'd cells i.e 8 cell connector and just let it balance.

Or just use your normal low power RC charger to balance charge to 4.15v a cell every week or so. Bulk charging is so much quicker and a lot cheaper and dare I say it more reliable.

I second this totally. im using the 900w version from bmsbattery. having a good charger is still a good idea imo, particually if you dont want to wait hours or days for a battery medic to balance your packs. and like others have said, this is one area you dont want to save every penny. because you'll either end up spending more to replace the broken stuff or worse yet end up damaging your batteries.

 

[knoxie]

Guys....paying £120 for a poxy 120watt charger for Lipo in Uk is crazy. I have to charge 17Ah of 66V Lipo and I got fed up very quickly of using a normal RC Charger.

So I bought a standard KP charger, you can get the 600W ones for $73 plus deliver from most places like http://www.bmsbattery.com/alloy-shell/27-alloy-shell-600w-lifepo4li-ionlead-acid-battery-ebike-charger.html

Just get them to adjust it so that it charges to you packs total i.e Cells x 4.15v and bulk charge it. The .5V headroom will stop any sneaky overcharging of cells and give you longer life of the lipo. Then I use a stand alone balancer that once a week I just leave on the series'd cells i.e 8 cell connector and just let it balance.

Or just use your normal low power RC charger to balance charge to 4.15v a cell every week or so. Bulk charging is so much quicker and a lot cheaper and dare I say it more reliable.

Have to disagree here! so without a BMS how does this charger monitor cell levels in your pack whilst its charging then? bulk charging lipo with no BMS is dangerous for newbs and not to be recommend at all, I can charge and balance my pack with each cell to cell level in under 2 hours safely with no worries, this isnt crazy my friend :| its cheap, safe and from my experience with lipo over the last 6 years, the most predictable and efficient method to charge lipo

 

[sn0wchyld]

Guys....paying £120 for a poxy 120watt charger for Lipo in Uk is crazy. I have to charge 17Ah of 66V Lipo and I got fed up very quickly of using a normal RC Charger.

So I bought a standard KP charger, you can get the 600W ones for $73 plus deliver from most places like http://www.bmsbattery.com/alloy-shell/27-alloy-shell-600w-lifepo4li-ionlead-acid-battery-ebike-charger.html

Just get them to adjust it so that it charges to you packs total i.e Cells x 4.15v and bulk charge it. The .5V headroom will stop any sneaky overcharging of cells and give you longer life of the lipo. Then I use a stand alone balancer that once a week I just leave on the series'd cells i.e 8 cell connector and just let it balance.

Or just use your normal low power RC charger to balance charge to 4.15v a cell every week or so. Bulk charging is so much quicker and a lot cheaper and dare I say it more reliable.

Have to disagree here! so without a BMS how does this charger monitor cell levels in your pack whilst its charging then? bulk charging lipo with no BMS is dangerous for newbs and not to be recommend at all, I can charge and balance my pack with each cell to cell level in under 2 hours safely with no worries, this isnt crazy my friend :| its cheap, safe and from my experience with lipo over the last 6 years, the most predictable and efficient method to charge lipo

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10952
thats what im using in conjunction with the bulk charger. Ive got the alarms set for 4.18v and 50mv delta V. I woldnt want to bulk charge without em though. I know what your saying re noobs and lipo, and I agree, though to be honest I think there's more risk if you have to reconfigure your pack each time to charge than there is if you bulk charge with some sort of cell level allarm/monitor.

 

[AussieJester]

+1 snowchild..seen more threads with kff
Because of mistakes with plugging and reconfiguring
Than I have seen rooted packs from bulk
Charging, its fast and simple and with a little common sense
Exercised very safe ..imo

KiM

 

[knoxie]

cell level balance charging for me is the safest option, I know exactly the state of each cell in each pack, no danger of paralleling at the balance connectors and 1 bad cell pulling the other one out either.

For newbs bulk charging with a BMS is fine and great but he was advocating bulk charging with no BMS or alarms= not great! the RC method is preferable to this but I do agree Bulk charging with a BMS is better for newbs than RC split and link for discharge for newbs, which is why it suits me coz I aint a newb and I run different voltages on different bikes with the same pack so I have to do it this way

 

[Spacey]

I have Cellog 8S on each 8S part of my pack. The 17.8Ah 66v is permanently wired up so that the only charging point is one XT60 charging plug that gets plugged into my 900W charger set for 66V.

The cells are never charged over 4.15v, 0.5v headroom on each of the 16 cells is a good headroom for charging and longevity. The cells are never out by more than 0.01V after 2 weeks of charging to 4.15v and discharging to 4.17v at the lowest. Charging takes just over an hour and is usually checked with the cell log 8's.

Once in a while I put the standalone balancer on each of the 8S balance connectors which are paralleled as in 3 x 8S 5.8Ah blocks soldered into 1 x 8S block including the balance connectors. It balances at 300ma so is not too slow, takes 3hrs to balance it packs so 6 hours every few weeks.

Before I had to have the jet turbine power supply powering my icharger 1010b+ which would charge at 300W max (more like 250W) for each of the packs so it was taking 3 hours a pack = 6hrs to charge the damn battery up. I have to charge to get to work then again to get home. I set a timer to come on 1.5hrs before I leave for work and 1.5hrs before I leave work. Works great so far.

The biggest danger is constantly unplugging and plugging in different packs, I have KFF'd twice from being tired. I would rather bulk charge with good headroom and check regularly than the faff that is charging each group at 250W.

 

[GaryJS]

Well guys, I think the bulk charging with cell level monitoring is sounding good for the future, but I have just dismantled my charger again and studied the circuit a bit and I think it MIGHT be repairable.. The trickiest bit will be the connector to the LCD that got burnt.. I've ordered 3 FETs (IRF7811A), 2 Diodes (SB530) and 4 caps (470uF but I ordered a slightly larger package that is rated for 4x the ripple current in case that was the weak point before) from Farnell and plan on having a dabble at fixing it tomorrow..

Wish me luck!

 

[knoxie]

so what if 1 cell goes out when you are charging, unless you charge them in the house within earshot or you have your celllog switching the charger off this is not safe, remember this is a newb option I am talking about, bulk charging with no BMS as you are suggesting is not safer than cell level balance RC charging, unless you have a cellog on each pack and you have them switching the charger off its not safe and hence my original point that if you arent using a BMS then RC charging is the best way forward for newbs as you can plug it in and forget about it without having to sit with the pack or keep an ear out for the cellog alarm the charger monitors it completely.

 

[GaryJS]

With one caveat knoxie.. You'll need to be in earshot if you use cheap hobbyking kit!

 

[Spacey]

knoxie true I understand that it is not safe for noobs but then really they shouldn't be using Lipo from the start. Just buy some A123 packs that will out last and perform all the same but a lot safer. As soon as this pack is finished I will be going A123 for sure.

 

[SamTexas]

Two items from my first hobbyking order have now exploded under normal use.. How bad is that?! And to top it all, it will cost me more to return the items than they are worth - Please.. Can anybody calm me down and recomend a replacement for my 4x6s Hobbyking charger?

FWIW, I bought 2 Supermate DC6 balance chargers from HobbyPartz.com and both of them failed within 2 days. I replaced one cap on one of them and it worked for another few days and something else failed. I gave up.

So I built my own charger using genuine Sony AC-LS5 adapters. No problems at all so far (4 mths, 100+ charge cycles). No more silly balancing.

 

[MadRhino]

I fast charge with Meanwells and Cell logs. I stay with my Lipos all the time they charge, which is not very long, and I find that it's safer than trusting an RC charger and go away.

 

[GaryJS]

Mine is a commuter bike so spending an hour+ a day watching lipo charge in my shed / garage (I'm not planning on bringing them into my house!) is not an option... I'd rather be inside playing with my 9 month old lad

 

[Gordo]

Space, check the typo.......discharging to 4.17V??????

 

[Spacey]

I keep on doing that typo lol broken arms still not healed so typo's galore. 4.15v charge 3.7v discharge.

 

[trappermike]

The problem?? (Oh boy everyone's gonna attack me on this...)
Hi-tech batteries. So expensive,and 1 bum cell screws everything...
I truly studied these batteries,but concluded-a lot of $$$$ spent,no guarantees,so many possible failure points.
Fine if you are rich and like to experiment. But NOT reliable for the PRICE.
MY 72v SLA's cannot fail,my bikes a rocket and they're cheap to replace.
I've studied hi-tech batteries over and over,yes very light for sure,reliable no in my opinion.
Well if you got lots of money to experiment,don't complain....

 

[sn0wchyld]

The problem?? (Oh boy everyone's gonna attack me on this...)......

pretty much...

Really?? my lipos are 'less' reliable than sla, but so long as you take care of em, they're way better. my 14v 5ah lipo's were ~25$ each delivered, SLA's I've found actually cost almost as much, and they last half as long at best. and given their charge/discharge efficiency to get the same amount out of sla i'd have to buy at least 2-3 times as much. Im not knocking you if you want to play it safe on a budget, sla is one of the safer budget batteries out there, but I have to disagree that they're the cheapest.

ps
1 bum cell doesnt screw everything, it might be a pita, but for me it'd be $50 and about an hours work to replace with new stuff. That's yet to happen in about 800km so far though...

so yea, your predictions were right, FLAME ON !! hehe. sorry dude, I just couldn't imagine strapping 40-60kg of lead to my bike vs the 6kg of lipo. (to get a roughly equivilant usable watts under heavy load)

 

[trappermike]

You're saying your 6 kg lipo is the same as 60 kg SLA?? 60Kg?even my mother-in-law didn't grow that big suddenly...(And she doesn't burst into flames-haha!)
I hope you are not inhaling any of the battery fumes when it's charging!!
Since you are so adament how about a fair comparison? What did it cost for your battery pack and charger,compare it to mine and see how it lasts for 3 years.
My 72v-10ah pack and charger cost me $270. 40 pounds yes.
What did yours cost,will it handle a 50 amp draw controller,mine does.Will it last 2-3 years,let's see? Most likely you have a pack with about 2C or 3C output,would die very fast with my motor.
You're tired of Hobbyking products because you can't admit your "Hi-tech" battery and such aren't reliable.
Your battery is 6kg,how big is it-volts and amp-hours?
Well let's compare...for 2-3 years.

 

[trappermike]

Well-how many watts is your bike really? How much power does your motor demand from your pack?

 

[Ricky_nz]

You know that Lead causes brain damage.... :lol:
Maybe someone has been licking the plates of his SLAs

 

[trappermike]

You know that Lead causes brain damage.... :lol:
Maybe someone has been licking the plates of his SLAs

Well gee... is that lithium for your battery or did your doctor prescribe it for you?

We've gone from actual electrical specs to insults from invertebrates.
Since you cannot engage me on a technical level... sink to insults.

Okay, how about this then. Give me the specs and price on your bikes electrical system. You think yours is so good, then show me how cost effective it really is.

 

[nechaus]

Lol you obviously have not done to much study ...
The only thing IMO that sla is good for is, solar or a power source that does not need to be moved much. . Even so sla is more expensive than my thunder sky's per wat hour I get. Where I live ... its funny to think of riding a ebike with chuncks of lead .. strapped only getting uptown 10ks without pedaling.. sla for people that don't have a job and rob the local junk yard .. lead acid can be just as dangerous if charged in a non ventilated room.. if not more .. lipos are not new technology in anyway ... they have been around for years

 

[nechaus]

I hope you realise your 10 AH is most likely rated at a 20 hour rate... so to even get close to your 10 ah you would have to run a load of .5 ah for 20 hours to reach that 10ah rating ...

 

[neptronix]

You're saying your 6 kg lipo is the same as 60 kg SLA?? 60Kg?even my mother-in-law didn't grow that big suddenly...(And she doesn't burst into flames-haha!)
I hope you are not inhaling any of the battery fumes when it's charging!!
Since you are so adament how about a fair comparison? What did it cost for your battery pack and charger,compare it to mine and see how it lasts for 3 years.
My 72v-10ah pack and charger cost me $270. 40 pounds yes.
What did yours cost,will it handle a 50 amp draw controller,mine does.Will it last 2-3 years,let's see? Most likely you have a pack with about 2C or 3C output,would die very fast with my motor.
You're tired of Hobbyking products because you can't admit your "Hi-tech" battery and such aren't reliable.
Your battery is 6kg,how big is it-volts and amp-hours?
Well let's compare...for 2-3 years.

lol... let's do a comparison.
A 5s 5AH 20C lipo pack is 640g.

You need 8 of those to make a 10S "72v" pack.
8 x 640g = 5120g.

That's 11.2 pounds versus your 40 pounds.

Your lead acid will also not give out the full 10AH due to peukert's effect.
Nor will it give the full watt-hours due to sag.
You'll probably get 5-7 AH out of it.

Worst case for the lipo is that you'll get 9.8AH out of it.
Best case is that you'll get 10.4AH out of it.

I couldn't imagine 40 pounds of battery on my bike. That must be miserable.

 

[sn0wchyld]

You're saying your 6 kg lipo is th.....

mate, chill out, you said people would flame you for touting the pros of sla's, and i just made some points and gave a bit of good natured ribbing. sorry if I caused offence, but I simply dont agree that sla is the cheapest out there when you take everything into account. There's a reason most people dont use sla.

What did yours cost,will it handle a 50 amp draw controller,mine does.Will it last 2-3 years,let's see? Most likely you have a pack with about 2C or 3C output,would die very fast with my motor.

I cant say yet how long mine will last, ive only got 25 cycles on it so far, but its actually been steadily improving in capacity during that time. Most report however that lipo under light loads will actually last for 500 or more cycles...

'Most likely' my pack is actually rated at a lowly 20c. I see 50 amp draws on a regular basis out of a 10ah pack, and it sags a whopping 2v or so. You say you've had it for 3 years, since most sla is only rated to around 3-400 cycles can I assume you dont cycle it every day?

You're saying your 6 kg lipo is the same as 60 kg SLA?? 60Kg?even my mother-in-law didn't grow that big suddenly...

and when I spoke about needing up to 60kg, that is to allow for the rather abismal discharge efficiency of sla under loads above .5c. at 20c, you may only get ~60% of your 'rated' capacity, ie a 10ah pack is actually only 6ah. with my lipo, i might get an efficiency of 95% if im unlucky. now im not running my lipo at 20c, more like ~5, but the efficiency of sla is still pretty bad at that rate, and as such I would need to carry extra capacity to make up for the loss in efficiency. Not to mention the loss of efficiency due to carrying the extra weight.

Also, thats a terrible thing to relate your MIL to a sla battery!!

I hope you are not inhaling any of the battery fumes when it's charging!!

Last time i checked, lead acid (non sealed, granted) were the prime culprits for gassing off during charging, and causing fireballs and explosions from a spark. Lipo is in a sealed pouch, and if they gass off, they're dead. Fames are rare if you dont overcharge em. Not a common occourance if you take care of em.

Since you are so adament how about a fair comparison? What did it cost for your battery pack and charger,compare it to mine and see how it lasts for 3 years.
My 72v-10ah pack and charger cost me $270. 40 pounds yes.

in terms of cost, yes, you win. Congrats. 12 * 25 = 300. Mind you, its minus $50 to get back to 76V nominal. + ~$220 for a top end charger that can charge from 0 to 100% in less than 1 hour. Thats right, a 1.3kw charger. Is that how much power yours puts out? More importantly, mine is likely to last upwards of 500 cycles, possibly even as much as 2+x that of sla. Add in the charge/discharge efficency, and over the life of the batts I'll prob be a few $ ahead. Might not be a big margin, but hell, Ill pay $100 to loose 10's of kg any day.

bbyking products because you can't admit your "Hi-tech" battery and such aren't reliable.
Your battery is 6kg,how big is it-volts and amp-hours?
Well let's compare...for 2-3 years.

and finally, its about 1kwh. 24s 10 ah, about 940wh to be exact. and at, lets say, 95% efficnecy, that is 893 what hours. Had this been a sla at 20c, you might be lucky and get a 60% discharge efficiency. Ie a tad below 600wh. 300 or 30% difference in capacity for something that wiehs less than a quarter as much, and costs a hundred or so more.

feel free to keep arguing too mate, like i said, flame ON!! heehe. Nothing like a good debate to distract me from exam study!!