Voltage on Solix Units

[DR Bass]

I have a Solix 15 G3 at the Bow and a Solix 12 G3 at the Console. Both on a dedicated circuit to a 100 ah lithium. 8 ga. wire to a fuse bus from battery and 10 ga. wire to each of the units.

Each unit will read over 12 volts (12.1-12.5) when on by itself. When I power the other unit on, voltage drops (according to screen "voltage supply") to 11.1 to 11.4.

Is this normal or acceptable?

Thanks.

[bobcoy]

Not normal or acceptable. What is the voltage at the battery. Either the battery or the connections are not adequate. You need to determine the drop between the battery and the unit to determine which it is. Bob

[DR Bass]

Multimeter reading at battery was like 14 or 15 volts. I'm guessing it is my connections. Using butt connectors to connect 10 ga homeruns to 18 ga. Humminbird power wires.

Why are the voltage levels good with one unit on?

[bobcoy]

The larger the load the more the drop. None of your numbers are good. A charged battery is 12.7 or 12.8 volts. Lithium is about 13.4. With no load(resistance) there will be no drop no matter how poor the connections are. Properly crimped, butt connectors are excellent. JMO Bob

[MichAngler]

I would also ask if you shortened the factory power cords

6 feet of 18awg can cause a large drop (I have 12 to 16 inches on each)

go back over your connections

you should see at least high 12 volts on both graphs

I have a 125 AH running 4 graphs and live scope with a very similar wire setup and I never see voltages that low

[bobcoy]

Depends on what you consider a large drop. From 6' of #18 with 3 amps I would guess .2 volts tops.

[bobcoy]

Was re-reading your post. If you used one Butt connector for the 10 to 18 gauge your 18 is probably a loose connection, The largest difference in wire for a Butt connector size will only mate a 10 to a 14 and that is not a great situation. I double the 14. 18 is only half that size. you need a screw terminal to accomplish that connection. Like I said with everything powered up read the voltage at the battery(to the tenth of a volt) and then at both finders and post the #s. We will figure this out. Bob
Let me add, with the charger unplugged.

[DR Bass]

Is a terminal strip a better choice than a soldered connection with a solder seal or shrink wrap over the top?

[Wayne P.]

Is a terminal strip a better choice than a soldered connection with a solder seal or shrink wrap over the top?

Yes a terminal strip or fuse block since it supports the "splice".

[DR Bass]

I just metered 11.5 volts at the battery with both Solix units running. It measured 13.6 with no load.
Bad battery?

[bobcoy]

I would be on the phone with the battery guy. Bob

[Mike2718]

I agree with Bob. There’s a very good chance your battery is bad. Instead of just testing the voltage on the battery, I would also try load testing the battery with a carbon pile load tester. That will truly tell you if the battery is good or bad. You can have a battery that measures 12.6 volts so you think it is a good battery but drops a lot as soon as you put a load on it. If it is a bad battery, you won’t get 12.6 volts after the load test.

[bobcoy]

Don't believe its possible with Lithium.

[Mike2718]

Don't believe its possible with Lithium.

I didn't know that. I thought you could load test to just under a 100 amps on a lithium. I have seen where 100 amps were applied to lithium batteries to see if the BMS would kick in and shut down the battery. I figured if you applied a little less than that, it would put enough load to see if it is good or not. Oh well. Forget that then. Thanks for the clarification. Don't need the OP ruining his battery although it may be bad anyway.

[tweakjr]

I just metered 11.5 volts at the battery with both Solix units running. It measured 13.6 with no load.
Bad battery?

That right there is the load test and tells you the battery is not performing.

[bobcoy]

I didn't know that. I thought you could load test to just under a 100 amps on a lithium. I have seen where 100 amps were applied to lithium batteries to see if the BMS would kick in and shut down the battery. I figured if you applied a little less than that, it would put enough load to see if it is good or not. Oh well. Forget that then. Thanks for the clarification. Don't need the OP ruining his battery although it may be bad anyway.

The load test that would be used on lead acid would not be good. Any drain of the battery will tell you something about it's health. There is still not a recognized test for Lithium. It would need to be tailored for particular batteries and their BMS programs. As the prior post said the load of the 2 units was enough to tell it's bad. Lithium needs to be respected as potentially dangerous even with LiFeP04 batteries. Bob

[WranglerSS]

I use the Ancor step down butt connectors to go from the Solix power wire to 10ga run to battery with adhesive lined heat shrink.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[MichAngler]

That right there is the load test and tells you the battery is not performing.

2nd

No need to look elsewhere

[Mike2718]

The load test that would be used on lead acid would not be good. Any drain of the battery will tell you something about it's health. There is still not a recognized test for Lithium. It would need to be tailored for particular batteries and their BMS programs. As the prior post said the load of the 2 units was enough to tell it's bad. Lithium needs to be respected as potentially dangerous even with LiFeP04 batteries. Bob

That’s good to know. I do, however, find it a little strange that my lithium battery is rated for 100 amps of continuous discharge and 350 amps of discharge for 3 seconds. I tested my previous lithium battery differently. I have a meter that measures amps, amp/hrs and volts. I connected an inverter to the battery and plugged a couple of fans into the inverter. I also plugged in an “old fashioned” electric clock that has an hr, min and second hand. I set it for 12:00. I started the fans, measured the current and let it go. I knew how long it ran by the time when the clock stopped. I was able to calculate the amp/hrs based on the current flow and time. It wasn’t completely necessary because my gauge measured all that. I had to “wake” the battery back up to get a reading on my gauge since it was inline with the battery. Turned out I was only getting 30 amp/hrs out of a 120 amp/hr battery so I knew it was bad. The fans only put out, if I remember correctly, 4 amps. That’s a heck of a lot less than my 500 amp carbon pile tester. Based on what you’re saying, I’ll stick to the fan and clock method to test this battery if I need to.

[DR Bass]

Thanks for the replies/help. The battery is an Amped 100ah lithium. I've had it and used it for about a year and a half in a kayak. They are standing behind their product and sending me a new battery. They have been very quick to get back to me.