Hi I have checked thru the forums and have not seen this specific question.
I have an IP 65 blue smart charger which consistently senses a higher voltage than is reported by the shunt, which is right next to it. This causes the charging algorithms to under charge the batteries or as I saw in one post to jump from bulk to absorption or float sooner than it should. Question is am I missing something or is this just a bad device or firmware?
Appreciate any responses. This occurs whether I’m charging a lithium battery or a lead acid battery and multiple battery brands and versions.
Hi. I have had no responses from the forum Your question is the first reply.
I have tested with a different IP65 charger….same symptoms and results. My only workaround has been to manually (expert mode) force The charge voltage (bulk/Absorption) to a higher voltage. I am sure an expert would probably tell me that the problem lies in where the battery voltage is being sensed. The IP 65 is reporting its pushed voltage versus what the battery actually reports receiving through the shunt adjacent to it. If I could network the IP 65 with the shunt as I do my charge controllers, I probably wouldn’t see this difference That would allow all devices to work off the same voltage value.
Incidentally….the difference between the voltage readings varies with the amperage… E.g. if I’m trying to charge with 15 A The voltage reported by the charger has a larger “error” then if I charge with 4 amps. Similarly, as the amperage decreases the voltage readings get closer.
If it was the only charger in the system, that would be true. However, when the IP 65 believes the voltage is 14.2 in a lithium profile default, it will enter into a two hour absorption mode before switching to float or storage. Unfortunately, at the same time, the actual battery voltage is only 13.7 and the solar charge controller Remains in bulk mode and soon exceeds the output voltage of the smart blue charger IP 65.
Between the two hour absorption time limit and the actual 13.7 output voltage the amperage contribution of the IP 65 reduces to zero with the battery bank not completely charged. By adjusting the charge profile on the IP 65 to reflect a higher voltage it will continue to contribute to the total amperage charge. (Again, remember it senses 14.2 when it’s really 13.7 At the battery terminals and the smart shunt. Telling it to charge at 14.7 or 14.6 forces the IP 65 to continue to contribute its 15amps to the total charging of the battery bank past 13.7 V).
The only wiring between the ip65 and the shunt are the wires built into the ip65. I have switched between the alligator clips and the ring terminal attachments but there is no difference . Without dismantling the ip65 itself there is no way to change the built in sealed wiring. The IP22 would allow this but not the IP65.
Hi Aubrey,
I finally had to approach it as I believe I described it before By customizing the charging algorithm in the IP65 smart charger. I leave the Solar charge controller (also a Victron ) with the standard lithium profile using 14.2 as its absorption voltage, but I set the smart charger to 14.5 or 14.6.
I believe the whole problem stems from the fact that the smart charger cannot be networked with the shunt, unlike the solar charge controller which can be. So, while the shunt and the solar charge controller are seeing the actual voltage of the battery the IP 65 smart charger is only seeing the voltage that it is trying to push. As the battery bank fills the two get closer in value.
I read somewhere that there were possible plans to network the IP 65 via a software update, however, I am not sure if that’s a priority for them.
IP22 smart charger Does network and probably doesn’t have this problem. If I had it to do over again, I would have purchased the other charger and not the IP 65.
I’m using a recently purchased Battery Smart Charger IP65 12/5 to top up the sealed lead-acid batteries of four cars and a lawn mower each week. I noticed that the Vstart records were curiously high. Today I compared the charging voltage shown via Bluetooth on the Victron app vs readings at the battery terminals made with two, good Fluke multimeters. The IP65 is showing 0.15V higher than the multimeters, early during Absorption phase. I suspect the delta is greater at the commencement of Bulk charging.
From reading earlier replies, it seems that this voltage discrepancy is a feature. I see no point returning and replacing if the new one will be the same. Any news in this respect? Perhaps there’s a production batch problem?
I will make more observations, comparing the IP65’s readings with those of the multimeters, at various stages of charging. A custom charging preset via the Advanced Settings could be the solution, though I notice there is no option for setting the Bulk charge voltage. I guess Bulk is always just full oomff, as per the maximum voltage and current settings for the preset.
Yeah the custom advanced settings are how I solved my problems with this. Replying to make one clarification. Bulk provides max amperage that the battery will accept (or the chargers max) until the Absorption voltage mark is reached. So from that perspective the bulk voltage is set with the absorption voltage setting. There is no other voltage setting specific to bulk by itself. It isn’t needed.
Bulk and absorption are the same target voltage. So there is no need to se thtem different.
The difference between the 2 stages it one stage it is rising to the voltage with current, the other is being held at that voltage not much current.
There always has to be some potential for power to flow.
If the battery is being undercharged, then there is cause for a warranty claim.
I have 4, have not seen a 0.5v difference. None of the batteries are over or undercharged and i do not have to adjust for anything.
The batteries all reach the target set and are held correctly.
There will be natural volt drop proportional to the charging current in the charging cable between the IP65 charger and the battery. I have the same charger. It can only read the true battery voltage when there is no current in the charging cable. If there is a poor connection or the charging cable is extended the volt drop will increase due to higher resistance. If there is a (consumer) load on the system while charging then the charger must satisfy both the load and the charging current and will experience greater volt drop due to the higher current while charging.
If you have a decent multimeter it could be useful to measure volt drops across all available connections in the system while charging just to be sure the natural volt drop is not being exacerbated by a poor connection somewhere. You can expect up to 50 mV across the shunt at rated loads but it should much less across fuses, isolators and cables.
I agree it would be nice if a future firmware upgrade enabled this popular charger to network with a smart shunt or even with other devices such as DCDC or solar chargers that may have less volt drop in their connections to the battery.
I’ve had the same issue for years.
It’s always been .3v difference though.
Lead acid, then lifepo4.
I did a lot of research online and was told the same as you. Check cable and connections.
My cable runs are very short, tight, clean and correctly sized.
Apparently the readings the inverter/shunt gives is from the cable, not the battery…???
Im no electrician but think it odd.
It also has to do with load and soc.
Just wanted to say thanks, SteveK, and everyone else who’s contributed to this thread.
I decided to purchase an IP22 12/30 charger in the end as my IP65 was out of warranty and my motorhome is in fairly constant use.
The IP22 has been working fine regarding voltage readings.
I’m going to keep my IP65 and use it as required as a backup and ad hoc charger for starter and other stand alone batteries. I’ll just be applying the increased .5v voltage in the advanced settings and monitor the actual battery voltage with a decent multimeter. Will also be interesting to see if there’s any change if and when new firmware comes out for it.
