1912 Baker Electric battery replacement

Post up a thread for your EV. Progress pics, description and assorted alliteration
rmlane
Groupie
Posts: 33
Joined: Sun, 19 Dec 2010, 03:39
Real Name: Richard Lane

1912 Baker Electric battery replacement

Post by rmlane » Wed, 22 Dec 2010, 23:28

So, the family has an electric vehicle already. It's the same one Jay Leno has - a century old Baker Electric.


The car is reliable and simple to drive (if completely different to modern vehicles - tiller steering from the rear seat, hand throttle).

The car is currently fitted with a dozen 12V lead acid batteries, two sets of 6 in series. 72 volt system, each string of six batteries can be turned on individually. The batteries are "car" batteries but quite large - the sort of thing you'd put in a small truck or boat. It's fitted with a large and old fashioned on-board charger.

The car could handle up to 80 volts and draws about 100 amps at max load.

Both the batteries and the charger are rather tired.

I'm looking for advice on whether there's a better solution for the battery than just buying a dozen deep cycle car/truck batteries and a new charger.

User avatar
acmotor
Senior Member
Posts: 3595
Joined: Thu, 26 Apr 2007, 03:30
Real Name: Tuarn
Location: Perth,Australia

1912 Baker Electric battery replacement

Post by acmotor » Thu, 23 Dec 2010, 01:06

Hi rmlane,
Welcome to the AEVA forum !
You'll get plenty of suggestions for battery options from the folk here.

I guess one has to ask what your expectations are of the Baker.
It won't be the daily commute as I expect the licence requirements are vintage holiday weekends daylight non freeway etc.

The other question is that of keeping the vehicle original i.e. deep cycle lead acid flooded batteries. Maybe not. I'm certain Baker would have fitted lithium cells if they were available at the time !!!

I'd be fitting Lithium Iron Phosphate cells (LiFePO4) with suitable battery management and charging system. This could extend operating range x 3 or reduce battery weigh by 3 while offering many years and thousands of cycles.
Check out the links for batteries
http://www.aeva.asn.au/links.php

BTW maximum battery range would be obtained with the two sets of batteries operated in parallel (minimises current, of particular importance with lead acid batteries) although I think the original one at a time idea was for peace of mind i.e. keeping half the capacity in reserve for the trip home.
iMiEV MY12     105,131km in pure Electric and loving it !

User avatar
Simon
Senior Member
Posts: 431
Joined: Sun, 19 Aug 2007, 19:38
Real Name: Simon
Location: Perth WA
Contact:

1912 Baker Electric battery replacement

Post by Simon » Thu, 23 Dec 2010, 02:12

Hi rmlane
I would say go with the Lithium too. Image
But I wonder how would the suspension go with a third or half the battery weight?
Could you post some photos of the Baker? I am sure we would all like to see some pics..

rmlane
Groupie
Posts: 33
Joined: Sun, 19 Dec 2010, 03:39
Real Name: Richard Lane

1912 Baker Electric battery replacement

Post by rmlane » Thu, 23 Dec 2010, 06:17

The plan is to occasionally use it for the daily commute once there are some convenient "electric car parking spaces" near my work in the CBD. My current vehicle is 53 years old, I've driven things up to 80 years old rounds town or in car rallies (closed road speed events).

The Baker is fully road registrable, as it is 100% compliant with the road rules... of 1912. It certainly isn't freeway or motorway capable - top speed is about 50 kmh.

That said, enthusiast based insurance puts some milage and usage restrictions on your cars - things like "twice a week" or "6,000 km a year" are normal.

As for originality: The lead acid batteries aren't original. Bakers were originally fitted with nickel-alkaline batteries, not lead acid. If I had the nickel batteries, I'd use those - they never wear out. They've been lost, however. Anyway, I have no qualms about dumping the modern lead acid for modern lithium.

The lead acid sets can be used in parallel, I'll keep that in mind when using them, but at the moment people are nervous about taking it long distances because we don't know how much range we can get our of the old batteries.

The suspension is half-elliptic springs at each corner, beam axles front and rear. No dampers. The car won't care about weight reduction of a couple of hundred kilos - it has no "handling" to lose in the first place.

Main aim of the upgrade would be to improve range and to have a discreet "power reserve" gauge hidden away somewhere - I assume you can instrument a LiFePO4 battery set so they you can determine its current state of charge?

Some quick reading suggests that I want to target a current drain of 0.5C to 0.8C - given the car can suck 80+ Amps, I'm going to need 100-160 Amp-hour batteries. Cell voltage seems to be 3.2v, I want ~80 volts, so 25 cells.

Something like 25 x SE180AHA? 140 kg. Even a set of 25 of the 400 AH ones only weighs 350kg - I would have to check the dimensions - are lithium batteries noticeably less dense/more bulky than the equivalent lead-acid cells?

Some pictures below - this is Jay Leno's one - used because it is easy to find photos online. Ours is the same model.

Image

Image

User avatar
EV2Go
Senior Member
Posts: 2059
Joined: Wed, 16 Jul 2008, 00:21
Real Name: Paul
Location: Brisbane 1963

1912 Baker Electric battery replacement

Post by EV2Go » Thu, 23 Dec 2010, 08:52

25 batts would give you a nominal voltage of 80v, but peak is more likely to be 90v (3.6v)

Depending on how far you want to go would determine if the 400Ah would be a better proposition than something like a 200Ah. Best thing to do is find the dimensions of the various Lithium batteries and see what would fit in the space you have available.

Yes you can get a SOC reading with Lithium, the new EMS I just purchased displays that as one of the outputs. Bear in mind that most SOC readings are average at best.

rmlane
Groupie
Posts: 33
Joined: Sun, 19 Dec 2010, 03:39
Real Name: Richard Lane

1912 Baker Electric battery replacement

Post by rmlane » Thu, 23 Dec 2010, 13:22

I'll do some more driving over Christmas and also get the dimensions of the two battery compartments (one at the front one at the rear). I'll also try and get some "cruising" amp values rather than concentrating on peak. And I'll double-check the peak voltage capability of the car - I might need to drop a couple of cells. Six lead-acid is 72V nominal, 84V peak?

If a 200-ish AH pack plus the BMS would fit into a single compartment, that would have the pleasant side effect of letting me use the other compartment as storage. I could have a boot! You can see the front compartment in both the pictures - it's the flat-toppped curved hatch at the front with the cute little chrome handle.

What's the simplest way to get 12V for the lights? Do you tap the main pack somehow, put in a little switch-mode power-supply to drop from 80V -> 12V, or do you run a separate 12V set of cells?
Last edited by rmlane on Thu, 23 Dec 2010, 03:31, edited 1 time in total.

rmlane
Groupie
Posts: 33
Joined: Sun, 19 Dec 2010, 03:39
Real Name: Richard Lane

1912 Baker Electric battery replacement

Post by rmlane » Thu, 23 Dec 2010, 15:13

Thanks for the advice so far, here’s some more quick questions:

Anyone know roughly how much 180-200AH cells and 400-ish AH cells are? I fired off a query to www.ev-power.com.au

How slowly do you have to drain a cell to get its nominal AH value? If I’m pulling 90 Amps out of a 180AH cell will I really get two hours?

A charger plus BMS for a 22-cell pack is roughly how much? A grand or two?

LiFePO4 cells apparently prefer to stay above 30% charge – lots more cycles if you don’t drain them below 20-30%. You kill them if you take them dead flat. That’s fine – however, the Baker will do a lot of very short trips (shops and back to get the milk, round the block to give people rides, etc). How do these cells cope with lots of 5-10% drain cycles. Drain 10%, recharge, repeat. Any memory effect or damage from small cycles?

OMG charging times... from a 10-amp circuit it looks like it’s 7-8 hours to charge a 22-cell 180AH pack, 16+ hours to charge a 400AH pack. And I’m running a low voltage pack in comparison to the other vehicles I see on this site. How on earth do you get reasonable charging times? Especially for people running those 50-90 cell packs!

User avatar
woody
Senior Member
Posts: 1714
Joined: Sat, 21 Jun 2008, 02:03
Real Name: Anthony Wood
Location: Mt Colah

1912 Baker Electric battery replacement

Post by woody » Thu, 23 Dec 2010, 15:22

What's your 53 year old ride? They made some cool cars in 57.

Which CBD are you commuting to?

For the 12V system - it's good (required?) to keep a separate 12V battery so you can run the hazards etc when the main pack is broken.

I think most use a switchmode to keep the separate 12V battery charged

You could charge the 12V when you charge the main pack.

Lithiums are about 1/3 dense than lead acid by volume.
Planned EV: '63 Cortina using AC and LiFePO4 Battery Pack

User avatar
woody
Senior Member
Posts: 1714
Joined: Sat, 21 Jun 2008, 02:03
Real Name: Anthony Wood
Location: Mt Colah

1912 Baker Electric battery replacement

Post by woody » Thu, 23 Dec 2010, 15:33

rmlane wrote: Thanks for the advice so far, here’s some more quick questions:

Anyone know roughly how much 180-200AH cells and 400-ish AH cells are? I fired off a query to www.ev-power.com.au
About $1.5 - $2/Ah i.e. $300 / $600 each. They are the most expensive bit. If your 80V * 100A is your peak then you won't need 200 or 400 Ah cells unless you want to drive interstate

How slowly do you have to drain a cell to get its nominal AH value? If I’m pulling 90 Amps out of a 180AH cell will I really get two hours?
Lead acid are normally at their 20 hour rate (AKA C/20), I think TS + SE quote their 1 hour rate (can't remember), so if I'm right, then yes you will get 2 hours

A charger plus BMS for a 22-cell pack is roughly how much? A grand or two?
BMS can be $2-$20 cell. Charger you could spend lots for e.g. 3 Phase (Zivan)

LiFePO4 cells apparently prefer to stay above 30% charge – lots more cycles if you don’t drain them below 20-30%. You kill them if you take them dead flat. That’s fine – however, the Baker will do a lot of very short trips (shops and back to get the milk, round the block to give people rides, etc). How do these cells cope with lots of 5-10% drain cycles. Drain 10%, recharge, repeat. Any memory effect or damage from small cycles?
Not sure, but you don't have to charge every night if there is.

OMG charging times... from a 10-amp circuit it looks like it’s 7-8 hours to charge a 22-cell 180AH pack, 16+ hours to charge a 400AH pack. And I’m running a low voltage pack in comparison to the other vehicles I see on this site. How on earth do you get reasonable charging times? Especially for people running those 50-90 cell packs!
You can get 15A circuits or even 20A, 30A, or run two 10-15A chargers on separate circuits. Or 3 phase 20A / 32A / 63A.
Planned EV: '63 Cortina using AC and LiFePO4 Battery Pack

rmlane
Groupie
Posts: 33
Joined: Sun, 19 Dec 2010, 03:39
Real Name: Richard Lane

1912 Baker Electric battery replacement

Post by rmlane » Thu, 23 Dec 2010, 15:44

The '57 is a Jaguar Mk VIII. Pic at the end of the post. Terribly unsuitable for conversion - weighs just over 1.8 tons. I tell myself it's OK because of the "Re-use" in "Re-use, reduce, recycle" (and I only drive about 6,000km a year). Also: Coolest car EVAR!

I'm in Sydney, about 10km from the CBD.

Roger - put a 12V system in and use that to run the lights. I'm unlikely to drive it at night other than driving 1km to the local shops/restaurant.

Sorry - lithiums are 1/3 less dense (2/3rds the weight) or 1/3 the weight? I'm talking physical density, not energy density. IE: If I fill up the exact same space that is full of lead-acid now, will the battery pack be 1/3 or 2/3 of the weight?

Image


rmlane
Groupie
Posts: 33
Joined: Sun, 19 Dec 2010, 03:39
Real Name: Richard Lane

1912 Baker Electric battery replacement

Post by rmlane » Thu, 23 Dec 2010, 15:56

woody wrote:About $1.5 - $2/Ah i.e. $300 / $600 each. They are the most expensive bit. If your 80V * 100A is your peak then you won't need 200 or 400 Ah cells unless you want to drive interstate
Ouch!

I was thinking 180AH was a minimum because I read that you want to drain the cells at less than 0.8C - however I could easily be misunderstanding the cell ratings.

If I'm driving any reasonable distance in the Baker it will spend a lot of time close to peak power - top speed is 50 Kmh, if I'm driving to town then I'll be running at over 50% of max power for 20 minutes, with long bursts of full power when the traffic is moving quickly.

What size would you normally recommend for 8 kVA peak draw?
Last edited by rmlane on Thu, 23 Dec 2010, 07:28, edited 1 time in total.

User avatar
woody
Senior Member
Posts: 1714
Joined: Sat, 21 Jun 2008, 02:03
Real Name: Anthony Wood
Location: Mt Colah

1912 Baker Electric battery replacement

Post by woody » Thu, 23 Dec 2010, 16:19

Mass Density - checking the specs (i have oldish specs in a spreadsheet)

Cylindrical Lithium (Headway, BMI) about 2kg/L
Prismatic Lithium (TS / SE) about 1.3-1.6 kg/L
Flooded Lead Acid (Exide E3600/E4800) about 2.2kg/L
Small Lead Acid (Greensaver / FirstStart) about 3 kg/L
LiPo (Wattsuprc) about 2kg/L

Most EVs drain their battery pack in about an hour IE 1C.

I think having real figures (cruising amps) will help, but on paper 5kWh will get my car 60km @ 50km/h.

*Edit 5kWh not 5kW
Last edited by woody on Thu, 23 Dec 2010, 05:35, edited 1 time in total.
Planned EV: '63 Cortina using AC and LiFePO4 Battery Pack

7circle
Senior Member
Posts: 540
Joined: Thu, 04 Feb 2010, 02:18
Real Name: Ken
Location: Melbourne

1912 Baker Electric battery replacement

Post by 7circle » Thu, 23 Dec 2010, 16:53

Wow, I wonder how many of these are still around, or in Australia.

Would the orignial Nickle alkaline actually be Nickle Cadmium (NiCd)
As you said "they never wear out." mmm We all wish we had cells that never wear out.

Many battery backup systems (or UPS - uninterruptable power supplies) still use NiCd I worked on a new charger systems that ended up with Westinghouse that used NiCd Cells more than 10 years ago.

So you could get NiCd or NiMH perhaps, but I would suggest LiFePO4 type cells like the SE180's you have already linked to.

I'm not sure what motor is in it but it would likely be similar to a old Forklift brushed motor. But it could have a Controlled Field Winding.

I would want to be careful with putting in these new types of batteries as the orignals may have had a high internal impedance (resistance)

An older (mmm .. oldest) controller like this may use a big resistor and tappings on the field to winding to vary torque.

It was all done with electrical contacts mechanically. The electrical analogue Valves, SCR's and transistors were not used.

I wonder what the original Light globes were they may have run of the 72V battery pack. Maybe they still do. Is there a separate 12V battery?

7circle
Senior Member
Posts: 540
Joined: Thu, 04 Feb 2010, 02:18
Real Name: Ken
Location: Melbourne

1912 Baker Electric battery replacement

Post by 7circle » Thu, 23 Dec 2010, 17:07

I looked up NiMh cells and these guys sell 100Ah prismatic.

The NiMH cells are Nickel Alkaline cells and don't have Cadmium to worry about, they are sold as environmentally friendly.

They can be discharged to flat. I would still recommend a smart BMS for them.
A BMS that uses small wires to sense the voltage on each cell would be suitable.

The Cycle Analyst device has a smart fuel gauge feature.

But NiMH pricing is perhaps not as competive as the LiFePO4, so shoosing between original technology or getting the car to travel twice as far is what you need to decide on.

Having a lighter car with an (in)efficient older motor will get you alot further.
Especially if it will be driving in hilly Syndey areas.
(Edit - Oops That was meant to be "inefficient older motor" as weight has greater influence)
Last edited by 7circle on Thu, 23 Dec 2010, 18:19, edited 1 time in total.

rmlane
Groupie
Posts: 33
Joined: Sun, 19 Dec 2010, 03:39
Real Name: Richard Lane

1912 Baker Electric battery replacement

Post by rmlane » Thu, 23 Dec 2010, 19:15

The original batteries are Nickel-Iron-alkaline not NiMh or NiCad. Nickel, Steel, Potassium Hydroxide. Basically indestructible - you can repeatedly drain them dead flat, massively overcharge them, etc, etc and they'll happily last 50+ years while being abused. Fairly cheap to manufacture. And you could re-charge them twice as fast as the lead-acid batteries of the same era. Before WW-1, they were the EV battery of choice.

Downsides? sh*tty power-density (worse than a modern lead-acid, though better than 100 year old lead-acid tech) and they self-discharge to dead-flat in about three months. They're "gassy" as well. Oh, and they haven't been made since 1975, and if I wanted originals I'd need "Edison" brand ones from the 1930s at the latest. Not going to happen :D

I'm not sure how many Baker's are left in Australia. I know of two, there might be a dozen but it seems unlikely.

The LFP batteries seem to be the best option - safety is important to me - I don't want a fault in the car leading to thermal runaway in the battery pack, followed by fire, followed by destruction of a century old piece of automotive history.

The motor controller is mechanical but not resistive. Decent sized quadrant-style lever (think "All ahead full! Aye, Aye, Cap’n!") with mechanical switchgear inside it. See YouTube link in my OP for a video of the controls. It has four (or five?) throttle settings. My guess is that the throttle switches various field windings on and off in the motor to alter the current draw. Given the top speed of 50 kmh, 4-5 power settings is enough.

Rod from EV-power in WA has been really helpful, I was able to use the advice from this forum to ask him sensible questions and he thinks 100 or 130 AH cells would easily be sufficient. Using a 24-cell pack also makes charging and maintenance simpler as it's a "standard" size pack (and equivalent to my 6x12V lead-acid setup) with an off-the-shelf charger available.

Full 130AH setup would run to roughly $6,500 including 24 cells, charger, BMS, "fuel gauge", GST and shipping. The whole pack is only going to weigh 105kg, which is a massive weight drop, and give me 10kwHr of power which is just tons compared to the worn out lead-acid pack. Should be enough for a couple of hours of motoring. I forgot to ask for a 12V auxiliary system to power the lights, but what.. $500, tops, including a step-down charger?

Dimensions of main pack would be tiny – if I’m doing the maths right, it’s only going to be about 36cm x 75cm x 30cm (LxWxH). Main pack, aux pack, BMS and both chargers should easily fit in one battery bay with tons of room to spare. Second battery back can have the picnic hamper in it :D

Big Kev Voice: I’m excited!

Of course, now I just need to save up seven grand.... (and get the 91 YO custodian’s permission to upgrade it). The former will be a lot more time consuming than the latter.

rmlane
Groupie
Posts: 33
Joined: Sun, 19 Dec 2010, 03:39
Real Name: Richard Lane

1912 Baker Electric battery replacement

Post by rmlane » Thu, 23 Dec 2010, 19:47

7circle wrote:Having a lighter car with an efficient older motor will get you alot further.
Especially if it will be driving in hilly Sydney areas.
Which gives me an idea for another project for a later day...

I have a 300kg car, complete with ICE, that I’m currently restoring. I’ve already had a friend tell me I should build an electric version. While I don’t want to trash my current ICE-powered car, I could get another one, sans engine and re-build it as an electric. I’d need to use a tiny pack and motor – the existing ICE + gearbox can easily be carried by two people (my Dad and I don’t bother using a hoist we just lift it out of the chassis) – so maybe 50kg?

I’ll have a think about it :) This one I’d need to source a motor...

User avatar
woody
Senior Member
Posts: 1714
Joined: Sat, 21 Jun 2008, 02:03
Real Name: Anthony Wood
Location: Mt Colah

1912 Baker Electric battery replacement

Post by woody » Thu, 23 Dec 2010, 19:58

rmlane wrote: I have a 300kg car, complete with ICE, that I’m currently restoring.
4 wheels? Isetta ? Meschersmit? Trojan? Triumph?

Planned EV: '63 Cortina using AC and LiFePO4 Battery Pack

rmlane
Groupie
Posts: 33
Joined: Sun, 19 Dec 2010, 03:39
Real Name: Richard Lane

1912 Baker Electric battery replacement

Post by rmlane » Thu, 23 Dec 2010, 20:37

1929 Austin 7. Four wheels.

User avatar
woody
Senior Member
Posts: 1714
Joined: Sat, 21 Jun 2008, 02:03
Real Name: Anthony Wood
Location: Mt Colah

1912 Baker Electric battery replacement

Post by woody » Thu, 23 Dec 2010, 21:18

rmlane wrote: 1929 Austin 7. Four wheels.
Nice. Rather have a 300kg car roll on you than a 1800kg one.



(Crash was 18 years ago, driver + car are fine, see YouTube comments)
Planned EV: '63 Cortina using AC and LiFePO4 Battery Pack

rmlane
Groupie
Posts: 33
Joined: Sun, 19 Dec 2010, 03:39
Real Name: Richard Lane

1912 Baker Electric battery replacement

Post by rmlane » Thu, 23 Dec 2010, 21:38

Ouch. That's fairly similar to what my Austin 7 looks like.

Poking around for motors for an A-7 conversion shows me just how low powered the Baker's motor is. The smallest motor I've found for a "micro-car" is 100 amp continuous, 300 amp peak... vs the Baker at 60/100...

72 volts also seems to be quite low. No wonder people are telling me that a small battery pack is fine for the Baker.

User avatar
Johny
Senior Member
Posts: 3729
Joined: Mon, 23 Jun 2008, 16:26
Real Name: John Wright
Location: Melbourne
Contact:

1912 Baker Electric battery replacement

Post by Johny » Thu, 23 Dec 2010, 21:44

rmlane wrote:72 volts also seems to be quite low. No wonder people are telling me that a small battery pack is fine for the Baker.
God I hate seeing prangs like that - no roll bar. Anyway the 50km/hr top speed is where the Baker gets it's modest power requirement from. Great to hear that these cars are being cared for.

rmlane
Groupie
Posts: 33
Joined: Sun, 19 Dec 2010, 03:39
Real Name: Richard Lane

1912 Baker Electric battery replacement

Post by rmlane » Thu, 23 Dec 2010, 21:53

I won't be racing my Austin 7, it isn't safe enough. That said... I have raced in a substantially quicker car with no roll-bar. The Austin 7 has a 4-cylinder, 747 CC side-valve motor that makes 10HP. I've done a full Targa Tasmania in a 2.3 litre, twin-overhead-cam, supercharged straight-8. From 1931. No roll-bar, no seat-belts. Goes like stink (over 200HP).

Nothing like a 4-wheel drift in a car with 4-inch wide tyres....

User avatar
Johny
Senior Member
Posts: 3729
Joined: Mon, 23 Jun 2008, 16:26
Real Name: John Wright
Location: Melbourne
Contact:

1912 Baker Electric battery replacement

Post by Johny » Thu, 23 Dec 2010, 21:57

Glad you're still intact enough to take care of that Baker...
I'm not fond of roll-overs - been in one too many (none where I was driving).

7circle
Senior Member
Posts: 540
Joined: Thu, 04 Feb 2010, 02:18
Real Name: Ken
Location: Melbourne

1912 Baker Electric battery replacement

Post by 7circle » Fri, 24 Dec 2010, 05:35

rmlane wrote:
7circle wrote:Having a lighter car with an efficient older motor will get you alot further.
Especially if it will be driving in hilly Sydney areas.
Which gives me an idea for another project for a later day...

I have a 300kg car, complete with ICE, that I’m currently restoring. I’ve already had a friend tell me I should build an electric version. While I don’t want to trash my current ICE-powered car, I could get another one, sans engine and re-build it as an electric. I’d need to use a tiny pack and motor – the existing ICE + gearbox can easily be carried by two people (my Dad and I don’t bother using a hoist we just lift it out of the chassis) – so maybe 50kg?

I’ll have a think about it :) This one I’d need to source a motor...


Ah it's very refreshing to hear that your willing to customise a second Austin-7 chassis as electric.

I love the old style coach building and interiors in cars up to the late 70's.
After that you only get it in very high end cars. So with an electric drive they could provide great commuting pleasure.

The Baker and Austin might be a bit harsh on the suspension for me.

I noted in my my post above that
"Having a lighter car with an (in)efficient older motor will get you alot further."

The poor efficiency of the Baker Motor will be more influenced by the reduction in weight by using LiFEPO4 SE130 cells.

24 x 3.2V x 130Ah will pack 10kWh.

I'd say that these cells will hold there voltage for longer, so top speed with the brushed motor wont "drag a leg" on the leg home.


7circle
Senior Member
Posts: 540
Joined: Thu, 04 Feb 2010, 02:18
Real Name: Ken
Location: Melbourne

1912 Baker Electric battery replacement

Post by 7circle » Fri, 24 Dec 2010, 06:07

Interesting read on te Ni-Fe Cells

This companis still importing them into the USA from China.
There pdf flyer has prices so A 80V pack could use 68 Cells so 10kWH back would need the 7009 Size with a 5hr discharge at 150Ah. So at less than 5 hr it will be even less, closer to 130Ah.
So the pack of 68 cells at 10kg is 680kg compared to 105kg for around 10kWh.
The 7009 price is listed at 16592 of Ah you get the 15% discount, so $8727.
SE130 are better for the wallet, if drifting from originality is allowed.

Post Reply