EV Traction Dry Cell battery - Absorption and Float settings

JakachiraJakachira Solar Expert Posts: 47
Hi folks

I just got my hands on a 235ah 12v battery EV4DA-A. This dude was kind of pricey and would not want to make any charging mistakes.

My charge controller is a Morningstar TSMPPT-60 and has the charging settings shown on the image below.

Attachment not found.

There is a setting for an AGM battery (this one they say its a EV traction dry cell battery but irregardless it's still an AGM, right?).

Looking at the graphs on the battery spec it says I should be able to charge maximum 14.4 to 14.7. I regard this range as very wide and would like you help to choose the correct values.

I am afraid of undercharging it and at the same time I am afraid of overcharging it. I have to say i stay in an area where temperatures are a bit on the high side.

So what settings do you thing I should choose (i can do custom settings but i am not overconfident in doing so)



  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: EV Traction Dry Cell battery - Absorption and Float settings

    I don't know what specs that battery should use, but I do know a "dry cell" is not an AGM. This doesn't mean the term is being used properly in this case or that the AGM settings won't work.

    AGM is Absorbed Glass Mat, aka "starved electrolyte". It is a lead-acid battery which has fibreglass mat between the plates and just enough electrolyte for the electrochemical reaction to take place.

    A dry cell uses dry chemical acid or alkaline as electrolyte. No doubt someone will tell me I'm wrong, but I'm not: it is not my fault people and even companies use terms incorrectly.

    From the look of the picture in the link (I am unable to see the data sheet clearly) it does in fact appear to be an AGM or at least a VRLA. It looks like the Absorb Voltage recommended is a whopping 2.6 Volts per cell, or 15.6 Volts. Again, I can not read the document clearly. Perhaps someone else can, as it does appear all the needed information is there.

    At that Voltage this would be a poor choice for RE applications as many charge controllers can't reach that level and most 12 Volt inverters would scream and shut down long before 15.6 Volts.

    You really should figure out if and how you're going to use something before you buy it. I suspect here that you will regret the purchase, and not just because a large portion of the price goes to paying for repeated use of the word "green".
  • JakachiraJakachira Solar Expert Posts: 47
    Re: EV Traction Dry Cell battery - Absorption and Float settings

    Thanks for the reply. Definitely you have read the battery spec incorrectly. The maximum voltage for bulk charging at 25degreesC is 14.7 as shown in the pdf. However, it says from 14.4 to 14.7 is OK. The gap is too wide to pick a setpoint without knowing exactly the consequences. They have a well-documented spec for this battery, if you don't mind you can open that PDF from a PC.

    As for the quality of this battery, it's one of the best battery in the local market. I have no doubt about that and the price says it all. The battery has a good warranty too.

    Thanks though.
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