Choosing a charger

[eman0079]

Hi my name is Erick and I'm working on a 914 Porsche electric
conversion for TCU. We're using 12, 12V deep-cycle blue top (agm)
optima batteries connected in series to make up our 144V battery pack
to run the car but I can't decide which charger to go with.

There's the quick-charge 12 bank ev charger (mb1210x12) that can
individually monitor and charge 12 12V batteries, meaning it can
correct for voltage imbalances, but I'm worried about hard wiring it.

And then there's the more traditional Russco ev SC 30 charger which
requires a transformer to step up to our voltage but can push out alot
of amps and has a 3-stage charging system tailored to optima
batteries.

I'm leaning towards the quick-charge to increase battery life but I'm
not sure. Does anyone have any ideas?

Any help would be greatly appreciated,
Erick

[John RA Benson]

go for the individual chargers. that way at least the bats will stay
balanced and there will be less worry about overcharging the healthy
bats. specially with agms.

jrab

[racunniff]

Just be careful. See TimK's adventures with individual Soneils at
http://civic-ev.blogspot.com/2009/06/very-dark-day-with-joule-chargers.html

For my battery replacement project, I'm going with the Manzanita
PFC-20 combined with Mk2 analog battery regulators.

Ross

On Aug 17, 4:54 pm, John RA Benson <j...@e-m-w.com> wrote:
> go for the individual chargers. that way at least the bats will stay  
> balanced and there will be less worry about overcharging the healthy  
> bats. specially with agms.
>
> jrab
>

[John RA Benson]

ouch. that's bad.
Tim's idea of using the light bulbs to replace the shunt resistors is
valid for the mk2 as well. if you need to shunt more current, it's
fairly cheap to get higher wattage bulbs or string in series. I wish I
had done that straight away with my setup. it might have made me
appreciate the mk2 a little better. They shunt, then overheat, then
fail. Then a battery fails, and will keep failing because of runaway.
I was never able to get my bats all caught up and keep them there -
despite monitoring every freaking charge. That's my adventure. Still
longing for a better solution that's affordable...

jrab

[racunniff]

Interesting idea - I assume the resistor in question on the mk2 is the
one hiding under the heatsink? I might disassemble one when they show
up...

Ross

On Aug 26, 3:14 pm, John RA Benson <j...@e-m-w.com> wrote:
> ouch. that's bad.
> Tim's idea of using the light bulbs to replace the shunt resistors is  
> valid for the mk2 as well. if you need to shunt more current, it's  
> fairly cheap to get higher wattage bulbs or string in series. I wish I  
> had done that straight away with my setup. it might have made me  
> appreciate the mk2 a little better. They shunt, then overheat, then  
> fail. Then a battery fails, and will keep failing because of runaway.  
> I was never able to get my bats all caught up and keep them there -  
> despite monitoring every freaking charge. That's my adventure. Still  
> longing for a better solution that's affordable...
>
> jrab
>

> On Aug 26, 2009, at 18:27, racunniff <rcunn...@gmail.com> wrote:
>
>
>
> > Just be careful.  See TimK's adventures with individual Soneils at

> >http://civic-ev.blogspot.com/2009/06/very-dark-day-with-joule-charger...

[Lou]

hi all i went with multiple chargers six months ago and i am happier http://www.chargingchargers.com/marine-battery-chargers/pro4.html i use them for overnight charging and when no more than 50% DOC because they are slow. i fall back onto the manzanita for faster charges but i know that the batteries  receive a balanced charge most of the time so they stay equalized. it was a lot of work in terms of the multiple wiring but worth it in the long run. here are photos of the set up --- On Wed, 8/26/09, John RA Benson <jr...@e-m-w.com> wrote:

From: John RA Benson <jr...@e-m-w.com> Subject: [914ev] Re: Choosing a charger To: "91...@googlegroups.com" <91...@googlegroups.com> Cc: "914ev" <91...@googlegroups.com> Date: Wednesday, August 26, 2009, 2:14 PM

ouch. that's bad. Tim's idea of using the light bulbs to replace the shunt resistors is  valid for the mk2 as well. if you need to shunt more current, it's  fairly cheap to get higher wattage bulbs or string in series. I wish I  had done that straight away with my setup. it might have made me  appreciate the mk2 a little better. They shunt, then overheat, then  fail. Then a battery fails, and will keep failing because of runaway.  I was never able to get my bats all caught up and keep them there -  despite monitoring every freaking charge. That's my adventure. Still  longing for a better solution that's affordable... jrab On Aug 26, 2009, at 18:27, racunniff <rcun...@gmail.com> wrote: > > Just be careful.  See TimK's adventures with individual Soneils at

> http://civic-ev.blogspot.com/2009/06/very-dark-day-with-joule-chargers.html

[Tim Kutscha]

Hi jrab,

I talked with the shop that used light bulbs as shunts and they
found that the bulbs kept burning out! I think the external power
resistor solution might be a better one than the light bulbs.
I've been using the Belktronix charging shunts for awhile now
and they seem to work reasonably well. I don't know if Belktronix
would sell just the shunts. If you ever go with a Belktronix charger,
make sure you get the Gen2.0 version (NOT Gen 1.5).

Just my two cents,
Tim

----- Original Message ----
From: John RA Benson <jr...@e-m-w.com>
To: "91...@googlegroups.com" <91...@googlegroups.com>
Cc: 914ev <91...@googlegroups.com>
Sent: Wednesday, August 26, 2009 2:14:03 PM
Subject: [914ev] Re: Choosing a charger