hi all. i have a customer that wants to replace a sunny island 4.4M-12 that is capable of charging kilowatt labs 3.55kWh super capacitors (ive seen some teardown videos and these are actually lithium titanite cells, but thats another thread altogether). the system has a 5.7kW array and customer has 3 of these kilowatt labs cells (10.6kWh). the promo/tech videos say they have no BMS and should work fine with victron but i wanted to confirm before i start going down this rabbit hole. the fact they are not really super caps sets of warning bells as it is. thanks in advance to all. cheers.
You should have been provided with a series of charging parameters with your LTO batteries, absorption, float, absorption termination time or current, minimum discharge etc. You need to program each piece of equipment specifically with these parameters. LTO are unsupported but if you search here or the old community (links below) you may find some info. I know LTO are advertised as more stable but the lack of BMS is worrying, are you sure that these will be a safe install.
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The titinate battery/cells should/will have a BMS.
More than fingers will be burned. Yikes.
The bms will have normal information such as charge and discharge parameters and maybe slightly different voltages, but like lifepo4 they have a management system. (It doesn’t help that marketing makes them sound like unicorns and fairies)
Surely the manufacturer has some guidelines if they say they are compatible?
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I moderated a few posts that drifted off the technical topic at hand.
My advice would be to avoid the situation unless you are ready to do some deep research and commit to the outcome.
There were dubious claims made when this product was first released, there is quite a bit of info on YouTube that look inside and run tests, and I wouldn’t suggest anyone try to summarise an outcome rather than go look at that primary research material.
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thanks guy. i tend to agree. im very wary of going near these things and will do and charge. i would rather replace the whole lot with pylon or powerplus and build a new victron box. thanks for the moderation. cheers
agree here too LX. i will charge by the hour and read the technical manual etc. thanks for the advice.
Hi Leon @SouthernOceanSolar
As a side note, still, Victron was/is used with supercapacitors, as they say in this blog: Victron Energy - Victron Professional
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thankyou alex i will take a look. much appreciated mate.
We have several older sites running KWL super capacitors / victron integrations, they work very well. However we would not recommend KWL anymore due to build quality. There are better capacitors available in the market at the moment.
@Leon Bateman- What is the exact model / version of the KWL caps do they have installed?
These units have internal control mechanisms for safety and protection, KWL has no BMS / Victron integration, we always install a battery monitor or smartshunt when integrating super capacitors / Victron. If you provide me with the exact model I can provide you with settings.
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thankyou martijn! it appears to be 3550-48-B-1.5C-M-SD-300RCB Version 2.0 Release date may 2018. i cant find this tech manual on the KWL website only similar versions. the customer has also added a 3rd pseudocap down the track to 2 initial packs. could this cause issues? any help is greatly appreciated.
Hi @SouthernOceanSolar,
The KWL caps can only be paired with caps of a similar type. Size can however be different.
If the voltage range of the cap is identical it should be ok. Just amend the config of charge controller, (smart) shunt or battery monitor and Inverter.
I’ll try find the manual for you.