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Adaptive charge, absorption time, temperature compensation & sensor.


I am getting a bit confused with the amount of information I am trying to take in so I thought I would join the community for some guidance, so thank you in advance.

I am on a easy solar 1600 24v system, 2x Rolls 290a, 50 Charge controller.

When using the formula, I managed to calculate an absorption time of 46mins (rounded up to 1hr)
Does this sound right?
T = 0.38 x C /I
0.475 = 0,38 x 260ah / 208

If this is incorrect then where have I gone wrong? Also, if I am using adaptive charge then does this figure matter?

I also was confused regarding temperature compensation - I saw that the compensation should be set at -4mV/ºC/Cell - so i have set this at-32V/ºC - is this correct?

The system has a temperature sensor, how do I know that it is even working?

Could you also advise on the absorption and float voltages please?
After looking through the manuals I settled for -
Absorption Voltage - 29.40V
Float Voltage - 27.60V
Max Charge Current - 50A

Also, i set the system to 'charge only' when I got to bed, in the morning despite the batteries reading at 24.8+ the system wont turn on until there is a bit of sun to top up the charge, or i need to turn the gene on to allow a top up... It could be for 5 mins and the system turns back on again and doesn't seem to be lacking charge at all.. is there something I have accidentally mis-configured when I was using veconfigure? I've noticed Victron connect app is not a comprehensive as Veconfigure or am i missing something by plugging into the charge controller?

Please excuse the basic questions but I have already fried one set of these batteries in 3 years and it was an expensive mistake i can let happen again... trying my best to get studying again : )



EasySolar All-in-Onetemperature compensation
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1 Answer
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kevgermany answered ·

Assuming your batteries are AGM

Solar.this will not start charging until panel voltage is 5V higher than the actual battery voltage. So your comment sounds like normal operation

Stick to battery manufacturer settings for the charging. Leave the absorption on adaptive. No need to change the default 8 hours max. Absorption time needed varies from day to day depending on use and conditions.

Easysolar is a housing with two main components inside, a solar controller and an inverter/charger. These need to be configured separately with the same battery parameters.

Yes connect and configure are separate products with differing levels of functionality.

Temp sensor is on the inverter/charger only. If you have an easysolar with GX display screen, the sensor values are in there. Otherwise you won't see it on a Bluetooth connection, but will using the MK3 USB cable to your pc.

To add temp compensation to the solar side, you need an extra sensor for the solar controller. It is not the same as the one you have and I think it's a cover off job to cable. You might find the socket for it is already wired up, not sure you need to check. I didn't bother on mine. I just set the solar charge voltage to the lower end of the battery maker's range. For me it's irrelevant in winter as there is so little sun.

Temp compensation. Six cells in 12V, 12 in 24 V. So in your case 48mV/C.

Hope I haven't missed anything, if so or not clear, ask!

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Thanks a lot for your response!

Yes the batteries are Rolls S12-290AGM-RE.

Thanks for letting me know about the charger not charging until the voltage is 5v+ the battery charge, i have noticed that it starts to accept a charge at 30w, however that isn't my concern - My system is set to turn off at 24v, each night before bed I set the system to charge only - it's when i come down in the morning to turn the system back on that It doesn't turn on, the battery is above 24v - has been at 25v at times and won't turn on until it gets to a certain voltage that I am yet to work out. I can't access veconfigure to go deeper into the settings to know if I have set a turning on voltage too low? Hopefully I can do that in a couple of days when we have our laptop back again.

I've got a mk3, however i need to update the inverter firmware to 415 then I can use victron connect at least on my mac so that'll make things a bit easier.

Regarding the temp senson - I have it setup and on the negative terminal, i also have the colour control but I have never seen a temperature reading - when i get connected to the inverter I'll have another look and see if I can find it.

Regarding the absorption time, i'm guessing by selecting adaptive charge I am bypassing the absorption time anyways? How did I get 1 hr from my calculations? haha!

Also, how did you get to 48mV/C. for temperature compensation? Also, i am assuming that should be -48mV/C.?

Thanks again!