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Discussion Starter · #1 ·
Aloha, I finally got my Yaris. 14 optima agms arrived at about 8volt each. Car has zilla and warp9. Anyway I have a few newbie questions (some kinda stupid, but I am getting my education). I would rather ask for advice about charging as the batteries are mostly old and end of their life cycle so have nothing to loose..... except I do not want to blow the Zilla or hairball. Anyways here goes:

1: I have 2 x 48v golf cart battery chargers that I was going to charge 4 batteries at a time. Question: If I was to charge 4x12v in series, I assume I could charge the next 4 batteries with the other charger at the same time because the charger is based on an isolation transformer?

2: Could I use one 48v golf cart charger and split it into 2xneg. and 2xpos. @ 48v outputs each (half the amperage though) and charge the first 4 batteries and skip 4 and hook up the second set of 48v -+ to # 9,10,11,12 battery. Question: will the middle 4 batteries isolate the + from the first bank of batteries and the - from the 3rd bank?

This is to play around with the car until I finally can afford lithium

thanks
francis
 

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Welcome to the EV world, it's a great sport.

Careful, a golf cart charger on my Optimas will overcharge them -- they tend to be setup for floodies, which can handle more abuse.

8V each doesn't sound good -- hopefully you can revive them.

You could call the charger manufacturer to make sure the charger is really isolated. Does the charger have a true "isolation transformer?" Many transformers are not actually isolation transformers (cheaper that way). A few batteries between charger A and charger B will not isolate the chargers.
Aloha, I finally got my Yaris. 14 optima agms arrived at about 8volt each. Car has zilla and warp9. Anyway I have a few newbie questions (some kinda stupid, but I am getting my education). I would rather ask for advice about charging as the batteries are mostly old and end of their life cycle so have nothing to loose..... except I do not want to blow the Zilla or hairball. Anyways here goes:

1: I have 2 x 48v golf cart battery chargers that I was going to charge 4 batteries at a time. Question: If I was to charge 4x12v in series, I assume I could charge the next 4 batteries with the other charger at the same time because the charger is based on an isolation transformer?

2: Could I use one 48v golf cart charger and split it into 2xneg. and 2xpos. @ 48v outputs each (half the amperage though) and charge the first 4 batteries and skip 4 and hook up the second set of 48v -+ to # 9,10,11,12 battery. Question: will the middle 4 batteries isolate the + from the first bank of batteries and the - from the 3rd bank?

This is to play around with the car until I finally can afford lithium

thanks
francis
 

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Discussion Starter · #3 ·
One more ? Can I hook the 48v charger outputs in series to make 96v? thanks
Francis
 

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Discussion Starter · #4 ·
OK I charged up all 14 12v Optimas and got varying results:

Starting voltage Ending voltage
#1 7.24 12,75
#2 6.37 12.64
#3 5.66 12.67
#4 4.71 12.77
#5 10.44 12.89
#6 5.25 12.59
#7 9.68 12.27 (got hot and outgassed)
#8 5.19 11.78 (got hot and gassed)
#9 8.45 12.44 (got somewhat hot)
#10 8.01 12.26

the ones #7 to 10 seem to be bad as the charger did not "throttle down" and kept charging at 12 amps. Total charge time for the groups of 3 batteries was 2 1/2 hours @ 12-15 Amps. (some went down to float at 2 amps

The #11 to 14 all charged to 12.65 or so but i only charged for 2 hours or less. Tomorrow I will check voltage and put a load on them to see if any are not shorted. Also will individually charge the lower voltage ones.

WaDaYa think
Francis
 

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Discussion Starter · #5 ·
Will these cheap chargers work? Two types on ebay. The 14 "orbital" 50ah 12v batteries in my Yaris are at the end of their life anyway. Here they are:

http://cgi.ebay.com/12V-10A-AC-DC-A...840?pt=LH_DefaultDomain_0&hash=item56419f0078

http://cgi.ebay.com/12V-10A-DC-Univ...993?pt=LH_DefaultDomain_0&hash=item4aa5cf4459

Do they put out 14v or so?

The second one says regulated and seems to have a pot to adj the V out.

Do you think they "throttle down to float when at the end of the charge?

Do you think they are Isolated in/out (110vac from 12vdc)

thanks
francis
 

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#1, No. You will need an adjustable 12 volt output because you want to push those batteries up to about 14.7 volts peak at end of charge.

#2, Perhaps. I see a voltage trim though I have no idea how much it can be pushed upward. How the supply shuts down in the even of over current is also important. You need one that will roll back voltage to not exceed max current to charge large batteries effectively. I notice that this seller doesn't combine shipping so you are looking at $25 per charger. It will really only work (maybe) with your current pack and you will need a new charger if you later go to Lithium.

Manzanita Micro is having a 1 day sale tomorrow. 10% off any charger. The PFC-20 is still $1845, but it is the kind of charger that you will want to keep around. You can adjust the voltage from about 12 volts to about 400 volts and set the current and timer functions to meet your needs. It will also really do 20 amps, input or output whichever comes first. I don't think you will get much of anything out of your current lead pack. Those starting voltages pretty much mean it was killed. They just won't have much capacity and their life has been cut down too. Sad to say, you are in the market for a new pack and charging system to go with it.
 

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Until you get your batteries into a more workeable condition, I would recommend you charge each battery individually with a standard "smart" 12v battery charger, preferably one with an AGM setting. Those power supplies will not do what you need them to, and the price is more expensive to boot. Look for something like this:

http://cgi.ebay.com/ebaymotors/15am...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

Once your batteries are more in line, you could bulk charge them.....
 
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