Yikes, 190 for a 144 nominal is a pretty high equalizing charge every time....

Sent from my iPhone

On Oct 22, 2013, at 1:27 PM, RightHand Engineering <[email protected]> 
wrote:

> Hi Steve,My comment is that the US distributor for Zivan seems to 
> consistently program the Zivan chargers to be too aggressive when charging 
> wet PbA batteries. I got an NG5 from them which charged my 144V pack to over 
> 190V each cycle, and that was in effect doing an EQ charge each cycle. I 
> checked with the manufacturer of my T-145 batteries (Trojan) and they agreed 
> that it wasn't good for the batteries. So I went back to the distributor and 
> asked to have it reprogrammed (for free), but they refused and defended their 
> charging profile as "good" for the batteries. My batteries were dead within 3 
> years, rather than the normal 5 years. I've since replaced my NG5 with a 
> PFC-30 by Manzanita.-Randywww.evalbum.com/1253
> 
>> Date: Tue, 22 Oct 2013 11:54:24 -0400
>> From: [email protected]
>> To: [email protected]
>> Subject: [EVDL] Charge profile on Zivan NG3 for 108V US Battery 125's
>> 
>> Below is the charge profile in my charger for a 108V pack if US-125's
>> 
>> Im = 13 Amps constant current until voltage hits U1 which is 128.7V
>> 
>> Hold voltage at U1 which is 128.7V until current fades to I2 which is
>> 6.7Amps.
>> 
>> Current is held constant at I2 which is 6.7 Amps for T3 which I am a little
>> unclear on, but I believe T3 ends when the voltage hits Um which is 132V
>> (seems very high for a 108V pack, but that is what the data sheet says).
>> 
>> Then it floats forever at 119V
>> 
>> I believe this profile is overaggressive and damaging the batteries,
>> espicially the part where it goes up to 132V.  So, I am looking for some
>> expert opinions as to if this is too aggressive.
>> 
>> Also, I plan to monitor the voltage and pull the plug at a certain point.
>> I believe I should terminate the charge somewhere around 130V, so I know
>> it is at least 80% charged.  Then literally plug it back in, which I
>> believe will go straight to the float charge.  This would essentially skip
>> step 3 of the charge cycle.
>> 
>> Does anyone know if I can actually do this and the charger will behave as I
>> am thinking it will?  If the pack is >80% charged when I unplug, wait a few
>> minutes, and plug back in, will it go straight to float charge mode?  I
>> would think it should as a safety precaution so as not to overcharge the
>> pack in case of a power outage (which is what I am simulating).  I know
>> other smart chargers go straight to float if they are near 80%, but the NG3
>> manual doesn't say anything about this.
>> 
>> Also, is there a way to fake out the temp sensor to trick it into charging
>> to a lower threshold?  That was my other idea.  Or, send it back and tell
>> them I need it programmed for small AGM batteries instead of these big
>> flooded batteries.
>> 
>> Thanks,
>> 
>> Steve
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