Does your PD 75A charger get 14.4v and 75A to batteries? - Montana Owners Club

hemiallen · 08-11-2021, 05:02 PM

Having an issue with my PD4575 Factory installed converter. It is running 14.1v at the charger as measured by a VOM, but through the Montana wiring it gets 14.0 to the disconnect, very little loss across the disconnect ( 0.04v) and 13.6v 46A at the battery shunt and battery as checked with a vom at the battery. Hmmm. Seems like a huge loss from the disconnect to the batteries. Trying to recharge 300Ah battleborns.

Next try at resolving this:
I ran a direct 4 gauge wire ( in addition to the factory wiring to help troubleshoot factory wiring) from the charger to the battery and it still only got 13.6v and 53 A. not much of a change in charging quality, but 53A vs 46A is a help. The 4 gauge is the largest the PD connector allows ( although PD guy says a 3 gauge should fit ( I only have 4 gauge available)

So I disconnected the external 4 gauge from a battery lug I added, and I ran direct from the PD charge system to the battery, and holding the 4 gauge and putting my vom across the wire and negative of one battery and I get 14v !!!! Seems good, but wait.

I connect that same wire back to the battery, and the batteries and shunt read 13.6v ? What the heck, are the batteries the problem of why the PD can't run the batteries up to 14.4v ( which is the recommended charge voltage for them) and 75 Amps? And when the batteries are at 100% according to the shunt the voltage goes up to 14.2 volts? PD guy says that makes sense once there is no load needed to recharge the batteries.

These are brand new batteries, and when installed the shunt read 14,4v, the In Command read 14v, but I failed to verify with the VOM but suspect it would have agree'd with the others.

HELP.....

Allen

carlrx7 · 08-11-2021, 05:15 PM

are you using the charge wizard function? How long are you letting it charge? 4 6v batteries can take some power. Let it go and once it starts getting full, the voltage will start to rise. Most I've seen is 60A in my 555AH of LiFePo4.

hemiallen · 08-11-2021, 05:27 PM

Sorry, this is 300Ah of battleborn Li batteries, using the Li switch. I did try the Lead position and charge wizard, and it made no difference at the shunt.

Allen

carlrx7 · 08-11-2021, 05:45 PM

The voltage will not get to 14.4 until it gets to the top 5% of battery capacity, then it will shoot up like a rocket. Yes, its a little lower than advertised but just need to let it charge.

hemiallen · 08-12-2021, 03:56 PM

Thanks Carl

Everything I read and ask ( battleborn also) the charge voltage from this unit should be, and stay, at 14.4v , 13.6 is for lead and a lead charger runs continuous at 13.6 regardless of load.

I get the feeling the PD is capable of producing 14v, and was verified, but when connected to a battery below fully charged the converter can't keep up like it should? Not sure if recharging at 14.4 and 53 amps ( both wires) will recharge faster than what I am seeing, which is 13.6 at 53A, but I suspect the converter SHOULD sustain 14.4 V like BB says it should , and their batteries prefer to get full use of them.

No reply from PD today, I'm thinking he'll want me to take it to a repair shop to verify my findings. He keeps asking if I have a loose connection and maybe heat due to poor connection, but my jumper direct from their lug to one battery surely can't have a loose connection unless it's deep in the Converter.

Thank you

Allen

carlrx7 · 08-12-2021, 05:03 PM

You will not see 14.4 volts until the batteries are full. As long as it is putting in amps, it’s not full yet. The load of the batteries are pulling the voltage down

jetskier · 08-12-2021, 08:40 PM

13.6V is the natural float voltage for the BB LiPO4. As stated, the 14.4-14.6 is only for bulk & absorption voltage when they are nearly full (>90%). They (BB) recommend holding the absorption voltage for 20 minutes for each battery. Most controllers (solar or chargers) have settings for float, absorption and absorption time.

https://battlebornbatteries.com/char...es-the-basics/

hemiallen · 08-12-2021, 10:15 PM

I am guessing this is what you are saying?
https://www.google.com/url?sa=i&url=...AAAAAdAAAAABAD

I assumed BULK is the function of recharging from deep discharge, like when I did the 68% draw down and that Battleborns suggestion of 14.4 was during bulk recharging. My old Lead system with charge wizard was able to recharge my lead batteries at 14v..... as measured with a cheap inline digital readout device ( before I knew what a shunt is). I guess I expect a claimed recharge of 14.4v 75A to actually read 14.4V 75A on my victron shunt. ?

I guess my initial results that it took my 13.6V / 46A recharge rate on my 300Ah battery bank taking 3 hours to fully charge them indicated a big problem as I assumed it would take 3 hours if the bank was depleted to around 20%.

If 13.6 is ok, I am still concerned that 46A seems like my Lead-acid drained to 12.2V recovered faster than these Lifpo4's are recharging for my boondocking .

Thank you

Allen

hemiallen · 08-12-2021, 10:45 PM

I am guessing this is what you are saying?
https://www.google.com/url?sa=i&url=...AAAAAdAAAAABAD

I assumed BULK is the function of recharging from deep discharge, like when I did the 68% draw down and that Battleborns suggestion of 14.4 was during bulk recharging. My old Lead system with charge wizard was able to recharge my lead batteries at 14v..... as measured with a cheap inline digital readout device ( before I knew what a shunt is). I guess I expect a claimed recharge of 14.4v 75A to actually read 14.4V 75A on my victron shunt.

I guess my initial results that it took my 13.6V / 46A recharge rate on my 300Ah battery bank taking 3 hours to fully charge them indicated a big problem as I assumed it would take 3 hours if the bank was depleted to around 20%.

If 13.6 is ok, I am still concerned that 46A seems slower than I expected to recharge the batteries.

Thank you

Allen

Daryles · 08-13-2021, 06:31 AM

Allen, I think you are OK with what you are seeing.
I looked up the specs for BB 100Ah 12v batteries and it says 50A max charging current per 100Ah battery. Im guessing the internal BMS manages that.. You got all 3 of your 100Ah batteries recharged in 3 hours (1 hour each). That's pretty good.
I have a PD4575K18LS8 converter. No lithium switch on mine. Just FLA with the charge wizzard.
It has been turned off for about 5 days. I'm only using the 400W of solar to keep the batteries topped off every day. I don't want to over charge them. I turned the convert back on to see what the charge wizzard would put out. Here are those results.

Batteries @ 84% (552Ah, lithium, max charge rate 65A).

Converter off: 13.18v. -4.72A
Converter on, Normal mode: 13.21v. 12.01A
Converter on, Boost mode: 13.28v. 32.10A

I did not disconnect the battery to see what the actual output voltage of the converter is but the current output speaks for itself.
With the batteries connected it puts a load on them and I can't see what the actual output of the converter is in each mode.
Also here is a diagram of how batteries should be connected in parallel just in case that might be a factor in your charging speed.

RipNC · 08-13-2021, 06:52 AM

Allen,

As soon as I set the lithium switch on my PD4575 it tripped the 50 amp auto-reset breaker in battery locker. Replaced the breaker with 80 amp manual rest and put out 14.4. My SG200 and shunt weren't in so not sure what the actual current was then (but exceeded 50A).

Mine also stays at 14.4 - 14.6. I think the lithium switch or the unit is bad. Have you tried cycling the lithium switch off/on again?

mlh · 08-13-2021, 06:58 PM

I just installed a lithium battery and was waiting to see what my charge voltage was. I also installed a new converter. I had hoped the old converter would be ok. I knew better. When I’m on shore power my plug in gage reads 14.4 volts and when unplugged 13.3.
I also installed a nice little 400 watt pure sine wave inverter to run the TV.
I do have a question. I have one battery and a 45 amp converter. What size fuse do I need between the converter and battery?
Lynwood

hemiallen · 08-13-2021, 07:24 PM

Thanks Rip

I do see the new resettable fuse you added, and the nice busbar for the battery positive that you added.
But I don't see the factory red fuse it replaces. I have a similar factory bar with several red wires coming off of it. Most are on grey AUTOMOTIVE resettable fuses, the one end one I can see is 30A but i'd have to tear the whole busbar down to read them all. At the right end is the power cable ( about 2 gauge-red) that came on the Lead battery and goes to that fuse, and next to it is the positive power to the 80 amp resettable fuse for the hydraulic system.

I am currently ( 3rd drawdown test) getting 60.48A average out of the PD after I added the second 4 gauge wire from the PD directly to one of the batteries. I will have to route it inside the rv as I added it to see if the factory wiring to the master battery switch and seemingly loner than needed cable for the battery recharging. Tempted, as per PD to make a short jumper ( both lugs) and step up to a 1/0 cable to the battery busbar with my own on-off switch, to shorten the cabling and as PD suggested less loss, but the 60A right now ( at again 13.66v) took just under 3 hours to recharge the 3 from 12.06V ( shunt power readout got messed up during the test so I don't know percentage of charge, just 12.06v) which I think is around 60%.

Not sure what fuse to use Lynwood, glad to see you are trying Li. I just ordered a 4th for 400A.

Thank you for all the feedback. Battleborn still says 14.4 is what should be at the shunt all the time during recharging, not 13.6 ( it did get to 14.44V&11.31A) when I am calling it topped out but it probably was still topping them off, but it is what it is, and again thanks for your feedback. Not trying to make a stand on what the PD should be running at, but my Lead system on my Rockwood I upgraded to a PD with wizard and get 14v recharging using a cheap inline volt meter, still unsure why my current rig doesn't.

Still learning, hopefully correctly....

Allen

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