# [EVDL] Charging U2200's



## EVDL List (Jul 27, 2007)

Hello John,

I would go with the 7.2 volts per battery for now and see how long it takes 
to get to 1.277 SG per cell which would be 100% State of Charge. That 
maximum voltage may be at 77 F. You may be able to adjust the voltage rate 
up when the temperature is below 77 f. and down when the temperature is over 
77 F. You will have to see what the Interstate specs call for this.

The 7.75 volt rate may be the same as a equalization charge which is done 
normally when the battery voltages vary more. My Trojan specs said I can go 
5 percent difference between batteries before I have to equalized. You could 
contact Interstate to see how often you should applied the 7.75 volts 
charge.

When I charge my batteries to 1.277 SG per cell to 100% SOC, then I reset my 
E-Meter either to the ampere-hour rating of the battery where it will count 
down or you can set it at 0 AH where it show how much you use.

Lets say you set it at 0 AH at 100% SOC, then when you use 10 AH, it will 
display -10 AH. Now when you charge the battery the E-Meter will count back 
to 0 AH. Turn off the charger and check the specific gravity and it not at 
1.277 SG, then charge it 10 percent more than you took out, or until the 
E-meter reads 0.1 AH which should be close enough for a SG reading between 
1.275 and 1.277 SG.

Roland


----- Original Message ----- 
From: "John G. Lussmyer" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Sunday, June 07, 2009 8:00 PM
Subject: [EVDL] Charging U2200's


> Okay, here I have this nice new pack of U2200's. There were all within
> a couple hundredths of 6.26v from the factory.
> Looking at the Interstate site, they say to bulk charge at 7.2v, and
> absorption phase at 7.75v. (seems kinda high to me.)
> I have 48 batteries in series, so that would be 345.6v bulk, and 372v
> absorption.
>
> So what voltage do I set my PFC-50 at?
>
> -- 
> --
> John G. Lussmyer mailto:[email protected]
> Electric Vehicle Battery Monitoring Systems, http://www.CasaDelGato.com
>
>
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## EVDL List (Jul 27, 2007)

The if they are US Battery/Interstate workaholics, Nawez from US 
Battery has on numerous occasions indicated regular everyday charging 
should be to 2.58 volts per cell + or - depending on the temperature.

I have Interstates and I have been setting my PFC-30 to the 
temperature adjusted equivalent of 2.58 volts per cell voltage 
setting and then have the timer start when acceptance voltage has 
been reached.

A few people on the list insist this is too high for everyday 
charging, but I am going on the advice of the manufactures VP of 
engineering (which is also the specs listed on their web site)

As for current levels I think it isc/10 up to the 2.58 per cell and 
then c/20 after.

There was a thread one or more years ago where Mark B. was having 
problems with his US battery batteries and it turned out it was 
because his charger was not capable of charging at the appropriate 
voltage / current combination. According to Nawez, Trojans and US 
Battery product are different by more than name and have different 
charge specs.

John




> Roland Wiench wrote:
> 
> > Hello John,
> >
> ...


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## EVDL List (Jul 27, 2007)

> John O'Connor wrote:
> > The if they are US Battery/Interstate workaholics, Nawez from US
> > Battery has on numerous occasions indicated regular everyday charging
> > should be to 2.58 volts per cell + or - depending on the temperature.
> ...


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## EVDL List (Jul 27, 2007)

> John G. Lussmyer wrote:
> 
> > Well, that does seem to match the Absorption Voltage they
> > specify on their website at:
> ...


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## EVDL List (Jul 27, 2007)

> John G. Lussmyer wrote:
> 
> > John O'Connor wrote:
> >> The if they are US Battery/Interstate workaholics, Nawez from US
> ...


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