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NG3 chargers can't current limit on lithium batteries?

60322 Views 144 Replies 21 Participants Last post by  jollmo
We've been using an NG3 charger for the last several years to charge our lead acid pack. We originally had Electric Conversions install an optional low current mode switch on the NG3 so that we could charge on a standard 15 amp outlet while at work.

We're in the process now of upgrading our pack to lithium. Before we purchased the new batteries we had contacted Electric Conversions regarding modifying our NG3 to handle the lithium batteries. They said they would be able to modify the charging profile for our configuration.

Now, after just receiving the charger back from Electric Conversions we noticed that the low power option had been removed from our unit. They failed to mention this little detail to us. I contacted them and all I was told was we can't current limit on lithium batteries and it would take to much time to do. If you can current limit on lead acid why not lithium? If the hardware of the NG3 supports current limiting on lead acid it should be just as capable of current limiting on lithium. I realize that it might require a separate charging profile or something but it can be done.

My plan now is to figure out the profile programming of the NG3 and modify it myself. I have a lot of professional experience in reverse engineering electronic systems and feel that it can be done. I know a lot of people have been down this path before on here and have found some decent information. If anyone has information about the NG3 charger that would help speed up the process it would be appreciated.

Two lessons here, NG3s don't currently have a current limiting capability on lithium and avoid Electric Conversions. After reading some of the other posts on here, I'm not the only one to have problems with this company.
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I have a used NG3 - it's set to charge LeadAcid at 144V. I want to alter the output voltage using the blue trim pots as mentioned in this thread.

However, the other instructions about measuring the output voltage do not work for me.

The instructions I've read say set the selector to 7 or F and disconnect any load on the output. In both cases when I test, I get a red flashing light and the on/off beeper/buzzer.

Does anyone have any tips for measuring/setting the NG3 output voltage?
Thank you.
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