How to take voltage reading at Power Center under sink area

[68camaro]

I am switching my batteries from AGM to Lithium and they will arrive tomorrow. My power center is set up for 12v AGM, voltage is set up to 12.7 or 13v. For lithium I need to increase voltage to 14.6v or the 16v listed on power center.

Using picture below, I do this in 2 to stages:

1. Move switch on the box from "3 stage" to "Fixed Output"; and
2. Turn the screw from 13v to 16.5v, while reading voltage to make sure I increase to correct voltage.

So my question is how do I read the voltage on the power center? Do I simply put the meter prongs where the white and black wires connect from silver box to fuse box? I assume I need batteries installed to get the power flowing, and do I raise to the 16.5v as printed on box or to 14.6 which is usually the 100% charge for lithium?

The last pic is a James River smallmouth for your viewing pleasure.


Thanks

[chin_k]

Can you provide the make and model of the charger? It is not the usual one that I see around here.

With the fact that I am completely foreign to your hardware, here is what I going to say: Yes, you can put the voltmeter on the output of the charger to check the voltage. I don't think you want to connect the battery, since it will drop the voltage to whatever the battery is at when it is charging up. I strongly suggest that you look at the manual of the charger to see if there is any instruction on the voltage adjustment for the output.

[68camaro]

Thanks chin_k, I have the Boonedocker 3-Stage 45 amp power center (BD1245PC), it is direct replacement to original. The directions are sparse and do not tell you where or how to take voltage reading.

If I take out and do test on workbench, I get no reading from +/- wires. I wonder if I need to reinstall to get reading?

[BobW9]

The 16.5V is the max, with 13 being the minumum. Set at the voltage specified by the batteries - for lithium that is usually 14.4 or 14.6.

Do NOT go to 16v, that is too high for any lithium pack that is nominally rated as 12V. My batteries specify the internal BMS will shut down if you tried to go past 14.8V.

The batteries will need to be connected in order to measure the voltage setting, and yes just put the leads on the plus and minus for either the charger, or on the batteries themselves. Make sure to start with the voltage dialed down to 13, then increase by turning the screw driver clockwise (looks like you’ll need a real small one for that). You’ll want to do this when you know the batteries are less than full.

For a lithium system I would really get a battery monitor that uses a shunt to measure the voltage and current at all times, so you can monitor what your system is doing.

The charger should stop when the current going into the batteries goes down to 1 amp or so. If you have the increasingly common lithium batteries in the usual group 28/31 size, then they will have an internal bms (battery management system) that will shut down when full, in case the charger goes longer than the batteries like. But you really should have that battery monitor with shunt, to be able to see what is happening, in case the charger or batteries have issues at some point.

[chin_k]

Some charger will not output power unless it is detecting reasonable voltage and polarity (that is, from the battery) on the output. Maybe you measured zero is because of this safety mechanism?

I would go with product with good customer support, however. This is one of the reasons Progressive Dynamics are often recommended among people in this group. Great product, customer service (phone and email) and made in the USA. Try to get info from the manufacturer if you can, since I do not have experience with the charger that you have.

[chin_k]

According to this, here is the re-branded version for the charger: https://powermaxconverters.com/wp-conte ... l-2018.pdf

https://www.rv.net/forum/index.cfm/fuse ... 906081.cfm

Again, I have no experience with the charger, and the link above seems to say it should output voltage without a battery... you can tell I have no clue at this point.

[68camaro]

The 16.5V is the max, with 13 being the minumum. Set at the voltage specified by the batteries - for lithium that is usually 14.4 or 14.6.

Thanks, I am using Lifeline and and the recommend charge voltage is just as you say.

Do NOT go to 16v, that is too high for any lithium pack that is nominally rated as 12V. My batteries specify the internal BMS will shut down if you tried to go past 14.8V.

Lifeline say their BMS shuts down at 15.4v.

The batteries will need to be connected in order to measure the voltage setting, and yes just put the leads on the plus and minus for either the charger, or on the batteries themselves. Make sure to start with the voltage dialed down to 13, then increase by turning the screw driver clockwise (looks like you’ll need a real small one for that). You’ll want to do this when you know the batteries are less than full.

Big thanks. I guess my worry is I need to take out power center mainboard leaving wires intact while its connect to battery to turn the screw since it is on side of main power box in my first pic.

I did find this video which does a great job of explaining and taking apart the Power Center and taking voltage measurements. Theirs is different system with no way to up voltage for lithium but everything else in video really helps bring this complicated little box into focus. Power Box starts at 2:20 and lasts 15 min..

https://www.youtube.com/watch?v=t_Qyur- ... =1&t=1661s

For a lithium system I would really get a battery monitor that uses a shunt to measure the voltage and current at all times, so you can monitor what your system is doing.

I was considering getting the Victron BMV712 but my battery has bluetooth capable BMS monitor, plus I am installing Victron Orion TR Smart DC/DC converter, so I am not sure I even need the BMV 712 with shunt battery monitor as that seems redundant. If I do find I need it I can add later.

[68camaro]

According to this, here is the re-branded version for the charger: https://powermaxconverters.com/wp-conte ... l-2018.pdf

https://www.rv.net/forum/index.cfm/fuse ... 906081.cfm

Again, I have no experience with the charger, and the link above seems to say it should output voltage without a battery... you can tell I have no clue at this point.

Thanks, the manual you attached was almost word for word identical to mine. The video I posted in previous post here said you do need to attach power source to get reading, I could not get reading myself on bench without power but I will try again later this week.

Good thread from rv forum, need to read again in morning.

Electricity is my nemesis, I never really feel comfortable around it.

[BobW9]

Good point about not wanting to have everything pulled out if you don't have enough room while connected to the batteries.

Well, you could do what I did one time, and just let the batteries’ BMS decide when to shutdown. You can adjust the setting to somewhere about the mid point, put things together, and let it charge. If you monitor the BMS using Bluetooth, you may be able to watch as voltage increases as the batteries get near full, and see what voltage its at when the BMS decides to shut down. Then go back and adjust a bit to get closer to the magic 14.4/14.6, let the batteries run down a bit, and try charging again.

I’m always a bit leery of relying on the internal BMS, but that is what it is there for, and doing it a few times like this shouldn’t be a problem. And since you have that app to tell you what the BMS is doing (nice, I have cheap batteries without that), if you watch closely, you can probably shut the charger off pretty quick, even before the BMS needs to intercede, if you see the voltage going over 14.6. Though if you don't see how high it goes, you may have to fiddle with the setting a few more times than if you let it go as high as it wants.

Also, note that setting dial should be linear, so if you see exactly how far around it goes from left to right, you should be able to guess about where it should be for 14.4/14.6. I.e. 13 - 16.5 is 3.5. 14.6 is 1.6 from 13 and 1.9 from 16.5. So the dial should be just under half way around to its max.

Good luck.

[68camaro]

Thanks Bob. I think out of gate I can do what you suggest with a little trial and error dialing it all in to get to correct volts. Once all is well, I will play around app to make sure its charging correctly and at spec’d rates.

I plan to install and dial in power center tomorrow so it should be an interesting couple hours.