Hybrid car battery packs for EV bike project.

[V-spec]

http://www.ebay.co.uk/itm/LEXUS-GS450H-2008-NEW-MODEL-HYBRID-BATTERY-CELL-PACK-PERFECT-/181130260547?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item2a2c347043

Hi All

I am seeing more and more hybrid cars being broken for spares and battery packs for sale! My question is has anyone ever stripped down a hybrid pack and reused its cells for a ev bike project? Can it be done? Im thinking of doing this for my project.

Thanks

V

 

[V-spec]

Ok everyone so i managed to buy a hybrid battery pack for cheap! i mean i paid £150 for a LEXUS MODEL CT200 HYBRID BATTERY CELL PACK, this has 28 NIMH 7.2v cells which are 6.5ah. My plan is to strip it down and somehow use them for my bike project.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=251277733535&ssPageName=ADME:B:BOC:GB:1123

High Output Battery
Using proven and reliable nickel-metal hydride technology, the Lexus Hybrid Drive system’s 202V, 36 DIN hp (27 kW) battery allows the new CT 200h to operate in EV mode, driving under electric motor power alone. Located beneath the rear loadspace floor, the fan-cooled battery pack size has been minimized to reduced impact on cabin accommodation.

27kw of power for £150 is a bargain if you ask me!

Any advice would be great such as BMS, Charging etc.

Thanks

V

 

[Monstarr]

There is a reason that this is not something many people do.
read in on the topics about the use of Prius batterymodules.
NiMH is a pain to charge and needs some kind of delta v detection to measure if the battery is full.
charging in parallel is not adviced.

allbattery sells a 40 cell nimh charger. Each 7.2v module contains 7 nimh cells. not ideally but the charger will charge 7 modules in serie.

as one of the few advantages they can put out massive amps.

 

[dogman dan]

That and nimh is heavy. But now that you have it, may as well invest in a charger. You might want to have more than 6 ah, so you may want two chargers if they are affordable.

Hint, RC charges have an nimh mode. Two hyperions? Two cheaper 8s chargers? Whatever you buy, a good RC charger will charge anything you ever run across in the future.

 

[peterperkins]

They aren't a pain to charge at all if you use a simple constant current dc led power supply of about 300-350ma for the 6.5ah sticks.
Combined with adequate ventilation they simply burn off excess charge as heat and self balance very nicely.
It's a technique we use to balance HV packs from Insight's, Civics etc etc.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=350728901913

http://www.ebay.co.uk/itm/AC-220V-DC-30-60V-12-18-x1W-Halogen-Lamp-LED-Power-Supply-Transformer-/290913834769

The ones above for instance cheap as chips and will charge a pack with a fully charged voltage from >30 <90V for the high speed boys.
Lower voltage versions are available. Just choose the voltage range to suit you number of sticks.
Charge overnight and job sorted.

I sell used Insight and Civic sticks in the UK £6.00 each plus postage or collect as many as you like.
They are incredibly robust and are a doddle to bolt together with M6 bolts and can deliver 100A or take 50A regen.

6 sticks gives a 6.5ah 43v nominal pack that weighs 6kg for £36.

 

[Monstarr]

That and nimh is heavy. But now that you have it, may as well invest in a charger. You might want to have more than 6 ah, so you may want two chargers if they are affordable.

Hint, RC charges have an nimh mode. Two hyperions? Two cheaper 8s chargers? Whatever you buy, a good RC charger will charge anything you ever run across in the future.

8s in NiMH terms is 9,6V. 7 NiMH modules (each containing 6 cells) in series will be 42s.
There are no RC chargers that will charge these amounts. Only 20s max as i recall correctly.

My 40s nimh allbattery charger charges to little less than 60V. At that point the modules are warm and usually be a bit swolen up indicating a full charge.

@PeterPerkins, i like the idea but charging 6500mAh packs with 350mA will take more than half a day. Thats way too long for daily use imho.

 

[Monstarr]

This is the 2A 48V charger btw.
http://www.all-battery.com/TenergyNiMHBatteryCharger01017.aspx

I see they also sell 1A chargers now for $18.74. They didnt sell them last year when i bought the 2A charger.
This would be a nice affordable solution to the parallel charging problem.
http://www.all-battery.com/48vsmartuniversalchargerfor40-cellbatterypack1a.aspx

 

[SamTexas]

8s in NiMH terms is 9,6V. 7 NiMH modules (each containing 6 cells) in series will be 42s.
There are no RC chargers that will charge these amounts. Only 20s max as i recall correctly.

Why do the number of cells in series matter? This is Nickel batteries, they don't need balance leads. So what are you talking about? Voltage?

 

[SamTexas]

6 sticks gives a 6.5ah 43v nominal pack that weighs 6kg for £30.

21Wh/lb. Is that just about as heavy as SLAs?

 

[Monstarr]

8s in NiMH terms is 9,6V. 7 NiMH modules (each containing 6 cells) in series will be 42s.
There are no RC chargers that will charge these amounts. Only 20s max as i recall correctly.

Why do the number of cells in series matter? This is Nickel batteries, they don't need balance leads. So what are you talking about? Voltage?

Because somebody was referring to the use of cheap 8s RC chargers to charge nimh. It has nothing to do with balancing, just the battery setup.

 

[SamTexas]

Because somebody was referring to the use of cheap 8s RC chargers to charge nimh. It has nothing to do with balancing, just the battery setup.

OK. Makes sense. 8s is 33.6V max. But nothing's wrong with using two 8s chargers in series or independently to charge a 48V Nickel battery.

 

[Monstarr]

You cannot charge nimh at high capacity with the lipo setting. The full charge indication requires a different approach then just measurement of voltage.
NiMH tends to drop in voltage when its reaching its fully charged state. They call that drop the delta v and is pretty sensitive. Lipo chargers will not read that.
So you have to use the NiMH setting on RC chargers which will be in the 40-42s area. There arent any 'Hyperion/iMax' type RC chargers that will support those NiMH configurations.

 

[docnjoj]

Astroflight still makes a charger for NiCd and NiMh that does 40S. Very accurate and may have heat detection shutoff these days. Mine is strictly electronic Dv/Dt.
otherdoc

 

[SamTexas]

You cannot charge nimh at high capacity with the lipo setting. The full charge indication requires a different approach then just measurement of voltage.
NiMH tends to drop in voltage when its reaching its fully charged state. They call that drop the delta v and is pretty sensitive. Lipo chargers will not read that.
So you have to use the NiMH setting on RC chargers which will be in the 40-42s area. There arent any 'Hyperion/iMax' type RC chargers that will support those NiMH configurations.

Who says anything about charging nickel batteries using the lithium setting? That would be catastrophic. I have in front of me a 6s lithium charger that supports 15s nickel. So an 8s lithium charger should support 20s nickel. 2 of them would charge a 48V nickel battery.

 

[Monstarr]

You cannot charge nimh at high capacity with the lipo setting. The full charge indication requires a different approach then just measurement of voltage.
NiMH tends to drop in voltage when its reaching its fully charged state. They call that drop the delta v and is pretty sensitive. Lipo chargers will not read that.
So you have to use the NiMH setting on RC chargers which will be in the 40-42s area. There arent any 'Hyperion/iMax' type RC chargers that will support those NiMH configurations.

Who says anything about charging nickel batteries using the lithium setting? That would be catastrophic. I have in front of me a 6s lithium charger that supports 15s nickel. So an 8s lithium charger should support 20s nickel. 2 of them would charge a 48V nickel battery.

Ok, you could do that idd. I thought u meant something else.

 

[Hillhater]

27kw of power for £150 is a bargain if you ask me!

That is 27kw max output ? ..not 27 kWhr capacity , .. i assume ?
202 volts , and 133Amp (max) from 28 x 7.2v modules

 

[V-spec]

The thing is i have 24 calb 40ah cells which put together are bulky and heavy. Im hoping to strip the battery pack down and reconfigure the cells to run 28/29volts which means putting them in series and parallel. Where would i start? would each cell pack in parallel need a separate charger? Should arrive this week ill start playing with it and post my progress.

http://www.direxplorers.com/dir-equipment-configuration-articles/328-nimh-batteries.html

some light reading.

Thanks

Vish

 

[V-spec]

So ive been doing alot of reading on these cells, and generally they are a pain in the a@se. Not as easy as Lifep04 or lipo. Why do the car manufacturers use them? I want to draw 70amps continuous and max upto 150amps. And they can be bloody dangerous enough to set your house on fire or punch a hole in you if you mess about and blow them up.

Right sounds like my kind of fun!

Vish

 

[67spyder]

How are you making out with building a pack from these cells? I just started a thread (before I found this one) about cutting up the battery from a hybrid GMC truck. The local insurance salvage has one with a reserve bid of $400 CDN (not far from 150 pounds you paid). I am looking at doing an ev conversion on a honda cub C70 small motorcycle.