We have Smart BMS CL 12/100 (HQ213244TWG, firmware 1.08 ) used as a current limiter (80amp Victron MegaFuse) from a standard 12V narrowboat alternator tht charges a LiFePo4, with a separate external BMS. Today for an unknown reason, it has been delivering zero current to the battery/DC system.
When checking via bluetooth on the Victron Connect App, the BMS is active (charge, load is active, the remote switch is closed, with Alternator ATC (On). There are no error-codes stated.
Whilst the engine is turn on, the alternator side voltage is 14.6V, and the the LiFePo4 is normal approx 13.5-14.0V. These readings I have confirmed with a seperate multi-meter.
The alternator does provide power or current when this was connected directly to the battery, so the issue seems to be related to the SmartBMS unit.
I wanted to check if this is unexpected behaviour (e.g. firmware bug) that needs further diagnosis, or simply the unit is faulty and needs to be returned?
@pumpkinteapot has it worked before? Are the three pin connectors daisy chained through the batteries? If that is the case, why is another external BMS involved? Are you using Victron Batteries? Is the 80 amp fuse tested ok?
The 3 pin connectors are daisy-chained to each other onto the same SmartBMS - this is a known un-official workaround for working with external BMS for non-Victron LiFePO4 batteries (but is understandably not supported by Victron).
80Amp fuses were both fine during testing.
This has been working before without any issues to date, which is why I am quite surprised the unit suddenly fails to transfer any current.
This was before the Orion Xs came along at the end of the last year as a cost effective alternative.
It seems to have failed, but wanted a confirmation from Victron. Sadly, there’s no way the company will accept the return, or even propose a solution to diagnose this.
I am not sure how it “current limits”. Could you explain that further?
I have not had bad experiences with failed equipment and returns. In fact they have always been very accomodating so if you are experiencing difficulty, that is unfortunate.
@Yachtbird It has a fuse on the alternator input to the BMS that the BMS uses as a crude current shunt and within the BMS it has a current control circuit to limit the alternator current to a max of circa 80-90% of the fuses value. I assume there will be some form of PWM driven FETs to achieve this.
As acknowledged by @pumpkinteapot the BMS is being used off piste, not connected to a set of Victron batteries. People have reported this works in the past but it is not supported by Victron, therefore it falls into a grey area for support and warranty.
@pwfarnell thanks for the update. I can see now you set the fuse size via Bluetooth and that sets the current limit function. Looks like a handy device.
@pwfarnell - yes exactly as described. I haven’t come across any other current shunts - except DC-DC chargers.
Having looked back - when you consider the cost of the BMS + OEM Mega Fuse + Victron BMS Cable - it is probably worthwhile now purchasing the Orion XS now on its way, if you can accept a lower charge. However, with inflation the price seems to be going up from last year…
The better option is to modify the alternator regulator directly - this can be a SpeedWake system or MasterVolt system which has better control over regulating the alternator excitation.
Unfortunately, these units are around £700, without labour costs. For mostly chinese alternators nowadays it is not worth bothering with. For commercial usage it’s probably better, however better alternatives exist. We already seeing hybrid engines (BetaMarine, now Canaline) offering high power charing (albeit 48v), but for those unable to retrofit and transitioning to Lithium on boats there aren’t many cost-effective options.
Does anybody know how to get Victron to accept a return, even if you don’t get a refund in order to understand what the issue is?