Converter charging amperage low?

[Fourkids&abeagle]

Hello all,
My two Battleborn BB100s (12v) only charge at about 10-11 amps max. I have already upgraded the converter to a Progressive Dynamics 4045LIKA (45 amps max) set to the Li mode (constant 14.6V) and the batteries are monitored by a Victron BMV-712.

I’ve checked the batteries, they’re both good and hold a charge. My question is, if the charger is rated for 45 amps, and my trailer is rated for 30 amp service, why do my batteries only charge at 10-11 amps when plugged into shore power?

I’ve searched the forum but couldn’t find anything and I’ve left several messages with Battleborn with no return call yet. Any help you can provide is much appreciated!

[ARoamer]

How discharged are your batteries when you are seeing 10-11A?
Did you get more amps before the converter swap?
Assuming everything is wired correctly-

Possibly a bad shunt / meter?
Possibly a bad converter?

BTW, 30A at 110vac is different than 45A at 12vdc. Your power supply draws 540 watts to make 45A @ 12vdc (ok.. close, 14.6v). Your trailer's 30A ac shore line can supply 3300 watts.

[Grumpy]

The 45 amps is the maximum output the converter can produce for running your 12 volt items. The battery charging circuit is usually much less.

[craigav]

What voltage are you reading when the charging is at ~11 amps? Part of the charger circuit design is to reduce the amperage to keep the voltage from exceeding 14.6v. ~CA

[ARoamer]

Originally Posted by Grumpy

The 45 amps is the maximum output the converter can produce for running your 12 volt items. The battery charging circuit is usually much less.

I'm not quite sure how this can be since the 12v battery and the 12v systems are wired together per Progressive dynamics install instructions.
...Unless I'm misunderstanding you and you think the 12v loads use most of the 45amps available.

[Grumpy]

Originally Posted by ARoamer

I'm not quite sure how this can be since the 12v battery and the 12v systems are wired together per Progressive dynamics install instructions.
...Unless I'm misunderstanding you and you think the 12v loads use most of the 45amps available.

No that is the maximum that it can supply.

This is from the spec for the 4600 series converters. 4635 4645 4655 as an example

Maximum DC Output Current 35-Amps 45-Amps 55-Amps

The charger varies based on what the battery needs to be recharged. It varies from full charge to a float charge. If the charging amps was a constant 45 amps you'd boil the batteries.

You can operate the rig without a battery and supply all the 12 appliances and lights and the converter will handle the load up to its maximum.

[Fourkids&abeagle]

Craig- it’s showing 9.96A at 13.5V. I know theyre almost full but that amperage is steady from 12.8V to about 13.6 then amperage tails off until 14.6V. It just never gets above about 10 amps even with a very low SOC (say 12.9V).

I know the shunt is good because it took exactly 4 hours to go from 80% SOC to full charge at 10 amps.

I should also mention that I’m plugged into my house’s 20 amp outlet. I know this may limit it some but 10 amps still seems low. All other appliances are off.

What about anyone else with 30amp service, LiFePo4, and a PD converter? You guys getting 20-30 amps in to the battery?

[ARoamer]

I agree something doesn't seem right.
Lithium batteries will take pretty much any charging current you can give them up to their BMS cutoff, depending on manufacturer, usually 100A each, but generally recommended charge rate is below 50A.
Being on 20A 110AC shouldn't be a limiting factor.
If your Lithium batteries are at 12.8V you should be seeing maximum output from your Progressive Dynamics supply, 10A is too low.
I would be contacting Progressive Dynamics.

[craigav]

I suspect either your converter is not set correctly (output switch), or something is wrong with it. It should put out 14.6v and have the full amps available up to that voltage. ~CA

[Fourkids&abeagle]

Thanks Roamer and Craig. You’ve confirmed my suspicions. I’ll call PD this week and post when I have resolved it.

[kcmusa]

Here is my idea, it happened to me.
I ungraded to a 70 amp converter, never saw more than 35 amps even when the battery’s were very low. Measured voltage at battery then at converter output while under load. I had a 2 volt drop because of the wire size and length. I ungraded the wire to some 4 ga I had. Now I see the full 70 amps when the battery’s need it.

[DanNJanice]

Originally Posted by kcmusa

Here is my idea, it happened to me.
I ungraded to a 70 amp converter, never saw more than 35 amps even when the battery’s were very low. Measured voltage at battery then at converter output while under load. I had a 2 volt drop because of the wire size and length. I ungraded the wire to some 4 ga I had. Now I see the full 70 amps when the battery’s need it.

^^^^Excellent point^^^^^

If you are using ANY wiring that was installed by the trailer manufacturer, you can almost bet it is cheap, poor quality, and undersized. There are calculators online that list wire gauge sizing for voltage sensitive applications (high current DC is one of them). When I have used the calculators I still go one wire gauge larger. I also use tinned Ancor Marine wire for everything I install, as well as pre-glued heat shrink tubing at the terminal ends.

[ARoamer]

Previous questions....

>>>>Did you get more amps before the converter swap?
>>>>Assuming everything is wired correctly-


Definitely agree with kcmusa, wrong wire gauge and / or length would cause this.

[01tundra]

What size wire and what is the circuit length between the batteries and converter?

Have you zero calibrated the BMV-712 yet?

I have 1/0 cable between the batteries and converter (PD9160ALV) with a wire pull length of about 2 feet.

[Fourkids&abeagle]

63 amps?! Wow. That’s good to see.
I never got more than 15 before the swap, and that’s the highest I’ve seen post swap.

Yes, I’ve calibrated the BMV-712 according to an earlier call with the Battleborn folks.

I have an X23B hybrid, and on that model the converter is on the back wall of the trailer, with the batteries on the tongue. So they are as far away from each other as possible, approximately 25 feet. So…based on what you guys are saying, it seems like the original wire is way too small for the distance and current.

I’ll try PD again tomorrow, but in the meantime o had to take my trailer back to storage and won’t be able to get to it at least until the weekend. But I think you guys have talked me on to the problem. I’ll have to plan a wire upgrade from the converter to the batteries.

[ARoamer]

>>"I never got more than 15 before the swap, and that’s the highest I’ve seen post swap."<<

Welp, that info helps! Not a converter issue.

>>"converter is on the back wall of the trailer, with the batteries on the tongue. So they are as far away from each other as possible, approximately 25 feet."<<

See if you can find a gauge marking on your wire, or measure the conductor diameter.
I'm curious to know what Jayco seems to think is adequate!

Here's a wire gauge calculator I like---
https://www.wirebarn.com/Wire-Calculator-_ep_41.html

According to your info, 2 GA or larger would be ideal. OR, run a smaller gauge to equal 2 GA (or larger) along with the existing wire.

Hopefully it will be an easy pull, 2 gauge at 25' may be a PITA especially if it's clamped / secured in places.

[01tundra]

Originally Posted by Fourkids&abeagle

63 amps?! Wow. That’s good to see.
I never got more than 15 before the swap, and that’s the highest I’ve seen post swap.

Yes, I’ve calibrated the BMV-712 according to an earlier call with the Battleborn folks.

I have an X23B hybrid, and on that model the converter is on the back wall of the trailer, with the batteries on the tongue. So they are as far away from each other as possible, approximately 25 feet. So…based on what you guys are saying, it seems like the original wire is way too small for the distance and current.

I’ll try PD again tomorrow, but in the meantime o had to take my trailer back to storage and won’t be able to get to it at least until the weekend. But I think you guys have talked me on to the problem. I’ll have to plan a wire upgrade from the converter to the batteries.

Yeah, our converter is rated at 60A, but the power wiring system has been optimized.

I figured that, it's common regardless of trailer brand.

On ours the batteries were on the tongue and the converter in the very back of the trailer, connected with 8 AWG wire.

First thing I'd consider is moving those batteries inside. You can get them closer to the converter, protect better against theft and have them in a more controlled temperature.

The second thing you can do is pull a larger wire between the batteries and converter, some people leave the factory wire and pull a second wire, but if you relocate the batteries I'd just run a new wire.

Below is how I rewired our trailer -

[kirkelli]

as your batteries charge your voltage charge current drops. If your batteries are discharged pretty good they will take full current from your charger and start to drop lower as your batteries start to peak. Also, you converter has a maximum charge current of 45A. Do you have a Battery Monitor installed?, one that requires a shunt for accurate reading.. This will give you complete information on your battery status, charging condition and amp hours etc.

[Fourkids&abeagle]

Roamer - yep, you’re right - I talked to PD and Battleborn today and they both confirmed 2 gauge is what I should have. So…guess what size is in there now? 8 gauge! I had no idea the factory wiring would be so undersized.

I went to the storage lot and towed it to an RV park nearby with full 30 amp connection. The converter is actual putting out 14.6 when I touch the output terminal. But when I touch a fuse, it’s already at 14.45, which matches the highest voltage I’ve gotten my batteries to. Strange. The battery voltage from the wires at the battery were 13.4, so I’m losing quite a bit from the 8 ga wires.

Tundra- thanks for the schematic! I have a lot of the same equipment - solar controller, blue sea, BMI-712, Battleborn, etc. I definitely need to add some fuses and a bus bar. Im going to print out your diagram and highlight the parts I have and then try to make them match as much as possible. That’s super helpful; thanks again.

Next step is to order some 2 ga and do a test run just to make sure the voltage and amps actually change. Then yes, it will be a huge PITA to run the new wires. It’s August in Vegas. Not gonn a be fun, but gotta get done. Will follow up later.

[craigav]

Originally Posted by Fourkids&abeagle

Roamer - yep, you’re right - I talked to PD and Battleborn today and they both confirmed 2 gauge is what I should have. So…guess what size is in there now? 8 gauge! I had no idea the factory wiring would be so undersized.

I went to the storage lot and towed it to an RV park nearby with full 30 amp connection. The converter is actual putting out 14.6 when I touch the output terminal. But when I touch a fuse, it’s already at 14.45, which matches the highest voltage I’ve gotten my batteries to. Strange. The battery voltage from the wires at the battery were 13.4, so I’m losing quite a bit from the 8 ga wires.

Tundra- thanks for the schematic! I have a lot of the same equipment - solar controller, blue sea, BMI-712, Battleborn, etc. I definitely need to add some fuses and a bus bar. Im going to print out your diagram and highlight the parts I have and then try to make them match as much as possible. That’s super helpful; thanks again.

Next step is to order some 2 ga and do a test run just to make sure the voltage and amps actually change. Then yes, it will be a huge PITA to run the new wires. It’s August in Vegas. Not gonn a be fun, but gotta get done. Will follow up later.

I certainly agree that going with 2awg would be best, however with that in mind, 8awg is rated to carry 40 amps (more with higher heat but 40a is common). Keep in mind that when you have a longer run the higher the current the more line loss which certainly could explain the voltage differences which the thicker 2awg wire will help you with.

Because of your consistent low amp readings from the converter though (I would double check the current output at the batteries and at the converter), I highly suspect that you have a poor terminal connection or similar component in the circuit creating higher resistance in the circuit somewhere which in turn is causing the lower amps. It is also possible the converter is putting out is rated amps but going somewhere other than the batteries. Running a new 2awg wire certainly may\should bypass whatever is causing the less than optimal connection(s) so again, I still think 2awg would be better overall, point being that if you can only get 10~15 amps across your 8awg, that in of itself indicates more resistance than what an 8awg cable has which again means you have a poor connection somewhere assuming the amp and voltage measurements you shared are correct.

If you don't already have a 12v dc clamp style amp\voltage meter, I would highly suggest you obtain one for this and any future issues as having accurate voltage and amperage measurements from multiple locations is needed to know for sure what is going on.

~CA

just a couple of charts, where you see that even 10awg is rated for 30 amps (fyi, your RV power cable is likely 10awg and can carry ~30 amps).

https://www.cerrowire.com/products/r...pacity-charts/

https://www.lapptannehill.com/resour...ampacity-chart