I am mid-way through a campervan build, and have just bought a second battery for my setup (the first was bought around a year ago). Both are Victron Lithium NG 12V 200Ah, with exactly the same part number (BAT512120620), but the new one looks slightly different, mainly what looks like a black cap on top (I haven’t tried unscrewing it ), which isn’t present on the first one.
My questions are, has the design just been updated, does the black cap have any relevance? And most importantly are they, in every meaningful way, still the same battery, and do I need to consider anything more before adding the new one to my system (it will be connected to the original one in parallel).
Many thanks in advance. Here is a picture for reference, don’t mind Henry, he wasn’t much help with this question.
OGPS
(Ed @ Off-Grid Power Systems - offgridps.com)
2
That black cap is a cover for the ventilation port so if a cell vents (releases a lot of hydrogen and other gasses) it can be piped overboard. Since you are putting the batteries in parallel you should be fine combining them.
I thought one of the advantages of LiFePO4 was that it was sealed so didn’t needed any venting to outside… are they now saying this must be vented to outside, or is it an optional thing?
OGPS
(Ed @ Off-Grid Power Systems - offgridps.com)
4
You are confusing off-gassing during charging to a catastrophic cell failure event. LFP batteries do not off-gas when properly charged like lead-acid chemistries do. Note the word properly. A quality battery has a BMS inside that will prevent catastrophic failures in almost all scenarios. But, like anything designed and manufactured by humans, there is always the possibility of failure. If you put LFP batteries in a small, confined, unventilated space then it is possible for flammable gasses to build up and ignite if there is an ignition source. This is extremely rare and with a quality battery configured properly it’s nothing to be concerned about. Using the Victron NG batteries along with a mandatory Victron NG BMS will work just fine so you don’t have anything to worry about.
Ah yes ok I see the difference… and yes I do have the Victron NG BMS in place, so just to clarify when you say I don’t have anything to worry about, do you mean even if I don’t vent to outside and leave the black cap in place? I guess the new battery would be no more or less at risk than the older battery that doesn’t have the vent at all
OGPS
(Ed @ Off-Grid Power Systems - offgridps.com)
6
That’s correct. I suspect, but I don’t know for certain, this is largely a requirement for ABYC certification.
), which isn’t present on the first one.