my battery reality

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my battery reality

Soren
I went ahead and converted a 1973 VW bus to electric  www.electricbus.blogspot.com
before I really knew (or still don't know) what I was doing.

Brief info.  I have a 144V system of 24 6V 220amp/h generic golf cart batteries and a Zivan NG-3 smart charger (programed by the factory) My stuff came from http://www.e-volks.com/about3.html except they have changed the charger in the kit, mine is the ng-3.

I have been asking around about how the charging should be working, and what I am getting is 154V after a full pack charge, and I can go 40 miles with big hills and be at 144 V at the end of the day.  I have read on this forum (some of Roland's posts) that charging should be much higher than that, up to over 7 volts per battery.  Is this just battery dependant, and I should stick with what I got, or am I undercharging my pack?  I just don't wan to kill my pack too early or miss out on added Volts I could be using.

In my driving I usually max out at 300 Amps under heavy acceleration, and cruise on the flats below 100.  My top speed is under 50 mph, so I'm stayign off the highways, would a different battery get me faster top end, or is that my motor talking to me, I just don't have much ooph in 4th gear (45 + mph)

P.S. I am using screw type connectrs, should I switch to clamp style to fit around the posts (I've read that here) would that affect performance, or is it just more likely a battery terminal will fail?


Thanks,  this is my first post to the group.

Soren
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Re: my battery reality

Bob Bath
You don't discuss the manufacturer, other than to say "generic."  Either they are US Battery, or they are Trojan.  Either way, you should be following the manufacturer's instructions.  Both have enough antimony in them, that yes, they need to go higher, depending on what you're talking about...
My 144V pack goes to 186V during summer, and 192V during winter, because of specific temperature compensation instructions, BUT, after I pull them off charge, the charge of the batteries IS around 154V.  So the question is, did you mean _after_ charge, with the NG3 going to 186 or so, they pop back down to 154, or is the NG3 only taking them to 154, in which case, you are horribly shortening the life of your batteries.

Some check state of charge with a hygrometer.  That works, but I just watch my current.  If it has dropped to about 3A-5A or so, I've got a sweet charge.  But once per week, I keep it on until current drops to C/10, which is about 1.5 amperes, adding water if nec.  As a result, my batts. are acting brand new, even though they're 1.5 years old.
Hope that helps,

Thinking about converting a gen. 5 ('92-95) Honda Civic?  My $23 "CivicWithACord" DVD (57 mins.) shows ins and outs you'll encounter, featuring a sedan; a del Sol, and a hatchback, each running 144V/18 batteries.  It focuses on component/instrumentation/battery placement and other considerations.  For more info,   http://home.budget.net/~bbath/CivicWithACord.html
                          ____
                       __/__|__\__
             =D-------/   - -     \
                      'O'-----'O'-'
Would you still drive your car if the tailpipe came out of the steering wheel?


--- On Fri, 6/13/08, glasers <[hidden email]> wrote:

> From: glasers <[hidden email]>
> Subject: [EVDL]  my battery reality
> To: [hidden email]
> Date: Friday, June 13, 2008, 10:41 PM
> I went ahead and converted a 1973 VW bus to electric
> www.electricbus.blogspot.com
> before I really knew (or still don't know) what I was
> doing.
>
> Brief info.  I have a 144V system of 24 6V 220amp/h generic
> golf cart
> batteries and a Zivan NG-3 smart charger (programed by the
> factory) My stuff
> came from http://www.e-volks.com/about3.html except they
> have changed the
> charger in the kit, mine is the ng-3.
>
> I have been asking around about how the charging should be
> working, and what
> I am getting is 154V after a full pack charge, and I can go
> 40 miles with
> big hills and be at 144 V at the end of the day.  I have
> read on this forum
> (some of Roland's posts) that charging should be much
> higher than that, up
> to over 7 volts per battery.  Is this just battery
> dependant, and I should
> stick with what I got, or am I undercharging my pack?  I
> just don't wan to
> kill my pack too early or miss out on added Volts I could
> be using.
>
> In my driving I usually max out at 300 Amps under heavy
> acceleration, and
> cruise on the flats below 100.  My top speed is under 50
> mph, so I'm stayign
> off the highways, would a different battery get me faster
> top end, or is
> that my motor talking to me, I just don't have much
> ooph in 4th gear (45 +
> mph)
>
>
> Thanks,  this is my first post to the group.
>
> Soren
>
> --
> View this message in context:
> http://www.nabble.com/my-battery-reality-tp17836114p17836114.html
> Sent from the Electric Vehicle Discussion List mailing list
> archive at Nabble.com.
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev


     

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Re: my battery reality

Peter VanDerWal
In reply to this post by Soren

> I have been asking around about how the charging should be working, and
> what
> I am getting is 154V after a full pack charge, and I can go 40 miles with
> big hills and be at 144 V at the end of the day.  I have read on this
> forum

Is 154V with the charger connected or after it's been removed?  154V is
not bad for a resting voltage, but WAY to low for a charge voltage.


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Re: my battery reality

Soren
I guess I hadn't realized there was a difference.  My charger is a pre-programed black box "smart charger" with no controls, I get 154 V after the charging cycle (which has a few different stages to it) So I feel better about that now.  I thought peoples resting pack voltage was 180V. I'll just have to trust the charger.

Soren

<quote author="Peter VanDerWal">


Is 154V with the charger connected or after it's been removed?  154V is
not bad for a resting voltage, but WAY to low for a charge voltage.


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Re: my battery reality

Soren
In reply to this post by Bob Bath
Hi Bob,

When I say generic, I mean generic, no brand name, labeled by the tire store I bought them from.  I will ask them to find out more for me.

I guess I was not understanding how chargiing works since my charger is a black box with no controls.. The after charge voltage is 154V  so I guess this is right.

I can't do any changes to my charging cycles, I just hope the charger is smart enough to help me out.  I'll have to write them a letter too. (Zivan NG-3 charger)

Do you have any suggestions as to what I should do with my battery ternminals.  Right now I did them with lead screw on tops,  Should I change these to copper ring lugs?  OR switch to wrap around lead lugs?  What are the neg consequences for sticking with the screw ons if they seem to be working?

Thanks Bob


Soren
<quote author="Bob Bath">
You don't discuss the manufacturer, other than to say "generic."  Either they are US Battery, or they are Trojan. (SNIP) did you mean _after_ charge, with the NG3 going to 186 or so, they pop back down to 154, or is the NG3 only taking them to 154, in which case, you are horribly shortening the life of your batteries.
(SNIP)
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Re: my battery reality

Richard Acuti
In reply to this post by Soren

Hi Soren,

As another vintage VW convertee, it's good to meet you. I also have the NG3 charger. The finishing voltage could be dependent on the battery but what we really need to know is if this is where the batteries are just before the charger shuts off, or is this the resting voltage a while after the charger shuts off. If it's the latter, then 154 volts is correct. Also, perhaps there's a little impedence in your voltmeter circuit that's causing a slight miscalibration.

Regarding your milage, amperage draw, and top speed, some of this sounds like a combination of terrain and driving habits and maybe motor choice. I'll guess that you're running an 8" or 9" motor and rule that out for now.

You mention using 4th gear. I think you may be "lugging" the motor. To get the most efficiency from the motor you should be running it in the higher RPM's. In my Beetle, I never use 4th and I've topped out at 70 mph.  Check on the Samba website archives for your gear ratio: www.thesamba.com and calculate the max RPMS's for each gear that your motor can handle. If you're anything like the Beetle, you should run about like this:

(I'm assuming you have a larger motor than I do with a lower RPM threshold)
1st: 0-25 mph
2nd: 25-50 mph
3rd: 50-60(65?) mph
4th: Never

You also mention steep hills. If you're getting 40 miles' range in hill country then you're doing pretty well especially since you're driving a brick. It's a shame you don't have regen.

Yes, a higher voltage flooded battery (like my 8 volts') would get you more speed but less range, and the hill-climbing would be kind of rough on them. 12v AGM batteries cheerfully give high current but they don't have as much capacity, lifespan and they cost more.

Try the shift points listed above, and cruising with the motor at higher RPM's. It's more gentle on the batteries and the motor. Your acceleration will probably be a little slower but you might get longer range and a little more top speed. You may even be able to safely go faster in each gear but use caution or you'll overspeed the motor and damage it. That's why I recommend calculating the motor RPM's in each gear vs. your motor's RPM limit as provided by your manufacturer. I can help you if you need.

Please post an update...I'm pretty curious how it all works out.
__________________________________
Message: 24
Date: Fri, 13 Jun 2008 22:41:01 -0700 (PDT)
From: glasers
Subject: [EVDL] my battery reality
To: [hidden email]
Message-ID:
Content-Type: text/plain; charset=us-ascii


I went ahead and converted a 1973 VW bus to electric
www.electricbus.blogspot.com
before I really knew (or still don't know) what I was doing.

Brief info. I have a 144V system of 24 6V 220amp/h generic golf cart
batteries and a Zivan NG-3 smart charger (programed by the factory) My stuff
came from http://www.e-volks.com/about3.html except they have changed the
charger in the kit, mine is the ng-3.

I have been asking around about how the charging should be working, and what
I am getting is 154V after a full pack charge, and I can go 40 miles with
big hills and be at 144 V at the end of the day. I have read on this forum
(some of Roland's posts) that charging should be much higher than that, up
to over 7 volts per battery. Is this just battery dependant, and I should
stick with what I got, or am I undercharging my pack? I just don't wan to
kill my pack too early or miss out on added Volts I could be using.

In my driving I usually max out at 300 Amps under heavy acceleration, and
cruise on the flats below 100. My top speed is under 50 mph, so I'm stayign
off the highways, would a different battery get me faster top end, or is
that my motor talking to me, I just don't have much ooph in 4th gear (45 +
mph)

Thanks, this is my first post to the group.

Soren
________________________________

Rich A.
Maryland
http://www.austinev.org/evalbum/371.html
http://patriotfuel.blogspot.com/




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Re: my battery reality

Soren

Richard Acuti wrote
Hi Soren,

As another vintage VW convertee, it's good to meet you. I also have the NG3 charger. The finishing voltage could be dependent on the battery but what we really need to know is if this is where the batteries are just before the charger shuts off, or is this the resting voltage a while after the charger shuts off. If it's the latter, then 154 volts is correct. Also, perhaps there's a little impedence in your voltmeter circuit that's causing a slight miscalibration.

Regarding your milage, amperage draw, and top speed, some of this sounds like a combination of terrain and driving habits and maybe motor choice. I'll guess that you're running an 8" or 9" motor and rule that out for now.

You mention using 4th gear. I think you may be "lugging" the motor. To get the most efficiency from the motor you should be running it in the higher RPM's. In my Beetle, I never use 4th and I've topped out at 70 mph.  Check on the Samba website archives for your gear ratio: www.thesamba.com and calculate the max RPMS's for each gear that your motor can handle. If you're anything like the Beetle, you should run about like this:

(I'm assuming you have a larger motor than I do with a lower RPM threshold)
1st: 0-25 mph
2nd: 25-50 mph
3rd: 50-60(65?) mph
4th: Never

You also mention steep hills. If you're getting 40 miles' range in hill country then you're doing pretty well especially since you're driving a brick. It's a shame you don't have regen.

Yes, a higher voltage flooded battery (like my 8 volts') would get you more speed but less range, and the hill-climbing would be kind of rough on them. 12v AGM batteries cheerfully give high current but they don't have as much capacity, lifespan and they cost more.

Try the shift points listed above, and cruising with the motor at higher RPM's. It's more gentle on the batteries and the motor. Your acceleration will probably be a little slower but you might get longer range and a little more top speed. You may even be able to safely go faster in each gear but use caution or you'll overspeed the motor and damage it. That's why I recommend calculating the motor RPM's in each gear vs. your motor's RPM limit as provided by your manufacturer. I can help you if you need.

Please post an update...I'm pretty curious how it all works out.
__________________________________
Message: 24
Date: Fri, 13 Jun 2008 22:41:01 -0700 (PDT)
From: glasers
Subject: [EVDL] my battery reality
To: ev@lists.sjsu.edu
Message-ID:
Content-Type: text/plain; charset=us-ascii


I went ahead and converted a 1973 VW bus to electric
www.electricbus.blogspot.com
before I really knew (or still don't know) what I was doing.

Brief info. I have a 144V system of 24 6V 220amp/h generic golf cart
batteries and a Zivan NG-3 smart charger (programed by the factory) My stuff
came from http://www.e-volks.com/about3.html except they have changed the
charger in the kit, mine is the ng-3.

I have been asking around about how the charging should be working, and what
I am getting is 154V after a full pack charge, and I can go 40 miles with
big hills and be at 144 V at the end of the day. I have read on this forum
(some of Roland's posts) that charging should be much higher than that, up
to over 7 volts per battery. Is this just battery dependant, and I should
stick with what I got, or am I undercharging my pack? I just don't wan to
kill my pack too early or miss out on added Volts I could be using.

In my driving I usually max out at 300 Amps under heavy acceleration, and
cruise on the flats below 100. My top speed is under 50 mph, so I'm stayign
off the highways, would a different battery get me faster top end, or is
that my motor talking to me, I just don't have much ooph in 4th gear (45 +
mph)

Thanks, this is my first post to the group.

Soren
________________________________

Rich A.
Maryland
http://www.austinev.org/evalbum/371.html
http://patriotfuel.blogspot.com/




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Re: my battery reality

Soren

This is what the motor company told me, but I am running 144 V.

The ES-31B is a Series wound DC drive motor. The operating range is 72-144. You do not want to exceed 6500 rpms on the motor. The most efficient rpm range for the motor is 2800-3600 rpms.
 
ES-31B
96 volts
150 amps
2950 rpm
13.6 HP
Continuous rated





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Re: my battery reality

Soren
In reply to this post by Richard Acuti

Hi Rich, My motor company sent me the following:

"The ES-31B is a Series wound DC drive motor. The operating range is 72-144. You do not want to exceed 6500 rpms on the motor. The most efficient rpm range for the motor is 2800-3600 rpms.
 
ES-31B
96 volts
150 amps
2950 rpm
13.6 HP
Continuous rated"

from that I was assuming I should top out at 4000 rpms, does that sound right?

In that case:

1st =16.8 mph
2nd=31.1
3rd=50.8
4th=72mph

based on mph= rpm x radius of tires/ gear ratio x final ratio x 168

tires = 12.3 inch radius measured
final drive = 4.57
rpm = 4000
1st = 3.8 ratio
2nd = 2.059
3rd = 1.261
4th = 0.889

I guess I have been switching gears too early if this is right.

gear info found at

 http://www.lovemybus.com/091BusGears.xls
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Re: my battery reality

Richard Acuti
In reply to this post by Soren

Oooh...good data! Well obviously, don't ever exceed 6500 rpm's or you'll scatter your motor all over the roadway.  

If your manufacturer says 3600 rpm's is the most efficient speed, then that's where you should run it, as often as possible. I mean, 4,000 rpms isn't far off from that anyway and probably wouldn't hurt. When you're hill climbing, you'll have to make a decision: Enjoying more torque by running the motor at a higher gear and a lower speed (generating a lot of heat and motor wear) or being satisfied with a lower vehicle speed and a higher, more efficient motor speed and less heat and motor wear.

At any rate, you've done the math and now you know what you can do. Based on your terrain and driving habits, you'll get whatever you get for range and top speed. Also, I noted that you said your RESTING voltage was 154 after the charger shut off. I believe that you're good in that respect. Yes, the Zivan is a black box with no controls but my experience after a year and a half, is that it's a solid, reliable charger for flooded batteries. Support from the company has been good. Don't draw 300 amps from your batteries for extended periods and you should be fine.
_______________________________________
Message: 27
Date: Sat, 14 Jun 2008 16:38:24 -0700 (PDT)
From: glasers
Subject: Re: [EVDL] my battery reality
To: [hidden email]
Message-ID:
Content-Type: text/plain; charset=us-ascii

Hi Rich, My motor company sent me the following:

"The ES-31B is a Series wound DC drive motor. The operating range is 72-144.
You do not want to exceed 6500 rpms on the motor. The most efficient rpm
range for the motor is 2800-3600 rpms.

ES-31B
96 volts
150 amps
2950 rpm
13.6 HP
Continuous rated"

from that I was assuming I should top out at 4000 rpms, does that sound
right?

In that case:

1st =16.8 mph
2nd=31.1
3rd=50.8
4th=72mph

based on mph= rpm x radius of tires/ gear ratio x final ratio x 168

tires = 12.3 inch radius measured
final drive = 4.57
rpm = 4000
1st = 3.8 ratio
2nd = 2.059
3rd = 1.261
4th = 0.889

I guess I have been switching gears too early if this is right.
gear info found at
http://www.lovemybus.com/091BusGears.xls
________________________________

Rich A.
Maryland
http://www.austinev.org/evalbum/371.html
http://patriotfuel.blogspot.com/




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Re: my battery reality

Soren

Thanks Rich,  I only hit 300 Amps for brief seconds everyonce in a while when I'm tryign to go fater than normal from a start (just testing it out still.)  I'm really going to have to push third gear more.

Do you use 1st gear?  It seems like 2nd starts me out really well. Even 3rd doesn't seem to be a problem.  On my forst big 40 mile day I left in in third almost entirely, but there were no hills that day, just start stop with lights and signs for 20 miles out and 20 miles back, all over town.

Let me know if the NG-3 keeps treating your batteries well.

Anyone else use the NG-3 with good results.
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Re: my battery reality

Richard Acuti
In reply to this post by Soren

Since you're using 6v batteries, 300 for brief seconds is ok..or so I've heard.  I do use first gear, but if I'm stopped on a downhill, I'll start out in 2nd. Starting out in 3rd seems like a bad idea. Sure, you can do it but you're just loading up the motor, making heat.

Like I said though, I think your motor is larger than mine, so starting out in 2nd probably isnt' as detrimental for you as it is for me.

A reader who's monitoring this thread sent me a Jet Electra operator's manual that gives good guidance for general EV driving habits. It's a lot of what I told you plus some finer points that I haven't. I'll forward it to you. It was good reading.
___________________________________
Message: 1
Date: Sun, 15 Jun 2008 10:35:02 -0700 (PDT)
From: glasers
Subject: Re: [EVDL] my battery reality
To: [hidden email]
Message-ID:
Content-Type: text/plain; charset=us-ascii

Thanks Rich, I only hit 300 Amps for brief seconds everyonce in a while
when I'm tryign to go fater than normal from a start (just testing it out
still.) I'm really going to have to push third gear more.

Do you use 1st gear? It seems like 2nd starts me out really well. Even 3rd
doesn't seem to be a problem. On my forst big 40 mile day I left in in
third almost entirely, but there were no hills that day, just start stop
with lights and signs for 20 miles out and 20 miles back, all over town.

Let me know if the NG-3 keeps treating your batteries well.

Anyone else use the NG-3 with good results.
________________________________

Rich A.
Maryland
http://www.austinev.org/evalbum/371.html
http://patriotfuel.blogspot.com/




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Re: my battery reality

Willie McKemie
> A reader who's monitoring this thread sent me a Jet Electra operator's manual that gives good guidance for general EV driving habits. It's a lot of what I told you plus some finer points that I haven't. I'll forward it to you. It was good reading.

Having JUST bought a Jet Escort, this REALLY piqued my interest.  If
you have it in electronic form, how about posting it somewhere?

--
Willie, ONWARD!  Through the fog!
http://counter.li.org Linux registered user #228836 since 1995
Debian3.1/GNU/Linux system uptime  183 days 12 hours 40 minutes

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