Hi, I would like to use LTC3305.
So, I have a question. Please help me.
I am experimenting with the LTC3305 evaluation board.
Use a super capacitor for the auxiliary cell,Lead batteries are used for BAT1 ~ 4.
I connected these with the evaluation board.Current did not flow through the auxiliary cell and the voltage remained at 0V.(BAT1 ~ BAT4: 12V lead acid battery, auxiliary cell: super capacitor)
The BAL LED (D5) was lit, so I think the status is “Balancing”.
The following was written in p.19 of the data sheet.
After startup, the current is limited by the increase in the resistance value of PTC, and the operation of charging very slowly becomes normal.* See “Pre-charge of auxiliary cells” below.https://www.analog.com/media/jp/technical-documentation/data-sheets/j3305.pdf#page=19
Using this as a reference, I left it connected for a while.
Then, there was a voltage rise of about 0.1V in about 10 minutes.Is this normal for operation?Please let me know if the charging speed increases as time passes, or the charging speed is very slow in the first 30 minutes.As a reference, we will share the experimental scenery.
I have tried connecting the balancer with 4 lead-acid batteries. For the auxiliary battery I used 6 series 20F EDLC. When the balancing begins I see a very high current (~20A) which charges the series EDLC to ~12V in small number of milliseconds. After that, balancing currents are normal (<1A). I suggest you try the following settings of the jumpers on the DC2043B.
JP1 - CONT
JP2 - EN
JP3 - 0
JP4 - 1
I understand that the datasheet discusses very slow turn initial charge for EDLC, and I do not know why I see very fast charge initially. It may depend on the jumper setting, but I am not sure yet. So, please try to duplicate my jumper settings to see whether that will cause initial fast charge.
Thank you for the answer.
JP1 to JP4 were set as specified.
However, the results did not change.I think that the capacity of EDLC is different between Taylor-san experiment and our experiment.
In our experiment, 40 EDLCs are used in 4 parallels of 10 series.
Is there a possibility that the charging speed will drop significantly if the capacity is too large?
Or is there an upper limit on the capacity that can be connected to the auxiliary cell?
What is the capacity of your 10S4P EDLC auxiliary 'battery'?
I will try a different DC2043B demo board to see whether I get the same results.
I'm sorry TaylorThe capacity value was wrong.50F is 10 series, 4 parallel.
When calculated, it becomes 20F.1 / (10/50) = 5F5F × 4 = 20F
By the way, EDLC used is a product of the following link.
How is the experiment progressing?
In the past, I think that 20F EDLC was tested in 6 series.Can you tell me the model number (manufacturer) of the EDLC used at that time?
Is it okay to use an aluminum electrolytic capacitor for the auxiliary cell?The capacity is about 800μF.
I think that a high voltage capacitor with low ESR and low leakage current is OK.
please tell me your opinion.