LifePo4 battery charger recommendations

Looking to replace my old Newmar phase three 24/240 volt battery charger with a high amp LifePo4 battery charger only.
I'm looking at the Victron Skylla-TG 24/100 230v. Anyone have any other recommendations? I want something with at least 100 amps. I have one house bank rated for 1200 amps. My Xantrex inverter/charger only puts out 60 amps. Also, would the two chargers working together get confused with the charge readings? I will try to duplicate the charge cycle, but wondering if this could be a problem.

Li-Time has a 80A LiFePo4 battery charger for under $300. I am thinking of getting it to jump my charging ability up from 125a to 205a.

tiltrider1 said:

Li-Time has a 80A LiFePo4 battery charger for under $300. I am thinking of getting it to jump my charging ability up from 125a to 205a.

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Even if the charger was 90% efficient, wouldn't that draw about 23amps of 120v current to deliver 205amp of DC current? Folks with a 30amp AC service or 5KW genset might have a tough time keeping up with that.

dhays said:

Even if the charger was 90% efficient, wouldn't that draw about 23amps of 120v current to deliver 205amp of DC current? Folks with a 30amp AC service or 5KW genset might have a tough time keeping up with that.

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I wasn’t recommending 205amps for anyone. I was responding to Mac2 wanting to add additional charging capability. I have a 9k genset so 23 amps isn’t much of a load for me.

Mac2 was concerned about whether two chargers would work well together and the answer is they will work together just fine.

tiltrider1 said:

Li-Time has a 80A LiFePo4 battery charger for under $300. I am thinking of getting it to jump my charging ability up from 125a to 205a.

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Im looking for 240 volt ac input to 24 volt output-100 amp or close to that.

One of the reasons I want the additional charger is to put a bigger load on my 21kw generator. Im wasting a lot of generator for a 60 amp charger.

Mac2 said:

One of the reasons I want the additional charger is to put a bigger load on my 21kw generator. Im wasting a lot of generator for a 60 amp charger.

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Yeah, very true. That is a lot of generator power. I only have a 6KW generator but still have to find something for it to do while charging so it maintains a decent load. Isn't that one of the advantage of the LiPo? That the absorb current stays higher for longer? I am not sure.

dhays said:

Yeah, very true. That is a lot of generator power. I only have a 6KW generator but still have to find something for it to do while charging so it maintains a decent load. Isn't that one of the advantage of the LiPo? That the absorb current stays higher for longer? I am not sure.

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I’m not sure how much of a difference either. All I know is that Im running my generator way to long to charge my isolated house bank. I still haven’t hooked up my solar panels and Im not getting anything from my 12v alternators. Future plan is 24v alternators to house bank and dc to dc chargers from house to start batteries.

Mac2 said:

Looking to replace my old Newmar phase three 24/240 volt battery charger with a high amp LifePo4 battery charger only.
I'm looking at the Victron Skylla-TG 24/100 230v. Anyone have any other recommendations? I want something with at least 100 amps. I have one house bank rated for 1200 amps. My Xantrex inverter/charger only puts out 60 amps. Also, would the two chargers working together get confused with the charge readings? I will try to duplicate the charge cycle, but wondering if this could be a problem.

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you have 1200A 24v battery lifepo4 bank 21 kw generator
for you be ideal be 530-600A charger minimum 250A

more said:

you have 1200A 24v battery lifepo4 bank 21 kw generator
for you be ideal be 530-600A charger minimum 250A

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Thank you! That gives me great perspective. I can only find chargers in the 100 amp range. I guess I’ll look at stacking chargers. I have seen chargers/inverters with higher rated chargers (I think around 200 amps). Not sure why they can’t make larger chargers, but I might go that route as well if it makes financial sense.

Mac2 said:

I’m not sure how much of a difference either. All I know is that Im running my generator way to long to charge my isolated house bank. I still haven’t hooked up my solar panels and Im not getting anything from my 12v alternators. Future plan is 24v alternators to house bank and dc to dc chargers from house to start batteries.

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I am dealing with a slightly similar but different issue. I have 1000ah of usable bank. I use 650ah in a 24 hour period. My recharge time is 6 hours. I am looking at ways to increase my recharge rate. I have a 9kw genset so loading it up is not an issue. I would like to keep my genset time to 4 hours or less out of 24.

It’s not an issue when traveling as the genset burns only .5 gph and you can’t hear it if the big motors are running. It’s more of an issue at anchor. Don’t mind it running in the am when every one is running hair driers and heaters but by noon I’d like to be done with it.

Good goal. Do you have solar?

When I acquired my boat it came with a Xantrax inverter/charger and 4ea 6 volt golf cart batteries. The batteries were run dry for who knows how long so I replaced them with 4ea 100aH lithium batteries. Since the Xantrex didn’t have a lithium charge profile I replaced it with a Victron Multiplus II inverter/charger and haven’t looked back. My recommendation would be to sell your Xantrex and purchase a Victron, you won’t be sorry.

J. Landin said:

When I acquired my boat it came with a Xantrax inverter/charger and 4ea 6 volt golf cart batteries. The batteries were run dry for who knows how long so I replaced them with 4ea 100aH lithium batteries. Since the Xantrex didn’t have a lithium charge profile I replaced it with a Victron Multiplus II inverter/charger and haven’t looked back. My recommendation would be to sell your Xantrex and purchase a Victron, you won’t be sorry.

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I would have but my xantrex (I have two) is programmable for the LifePo4 charge profile.

FWIW. I have twin Magnum 2000w inverter chargers. 800Ah LFP. When the 8Kw GEN is running they each output 115A for 230A but usually about 30A goes to feeding the ongoing loads. When running GEN and underway another 100A via DC2DC from start batts adds to the 220. As good as it sounds the input to the house bank is not near 300A, I think the multiple charge sources derate each other. Maybe the BMS throttles the max charge it will accept. In theory the batts will accpet 400A charge.
In any event, I am satisfied running GEN 2-4 hours a day during peak use.

I had a Skylla TG on my last boat, and dual Skylla-i on the current boat. The good part is that they reliably put out 100A across all encountered ambient temps. This is in sharp contrast to the charge output from my Quattro inverter/chargers. The Skyllas also have remove voltage sense which I think is mandatory for LFP since a couple tenths of a volt is the difference between charged, and not charged.

The down side is that adjusting the voltages is a royal PITA. You need to disconnect the charger output, disconnect BOTH the pos and neg sense leads (I don't know why you also need to disconnect the neg lead, but I discovered this the hard way), then fiddle with POTS on the circuit board that only responss after you turn them a bit, which pretty much ensures they are always starting from the wrong point. But once sent up, they work well.

The TG is dumb as a stump, which may be preferable over the Skylla-i which is smart enough to be really, really stupid. The TG you can set absorb time to 0 hrs which I think is preferable for LFP - certainly way better than 4 hrs which is the lowest for the TG. The I can be monitored via CAN bus, but it can't really be controlled by a BMS.

Both, frankly, as a disappointment and I hope Victron comes out with new models soon. The up side is that very few people make a 100A 24V charger. I think Mastervolt does, but I don't trust them to get anything right at this point, and support is completely non-existant.

Mac2 said:

Thank you! That gives me great perspective. I can only find chargers in the 100 amp range. I guess I’ll look at stacking chargers. I have seen chargers/inverters with higher rated chargers (I think around 200 amps). Not sure why they can’t make larger chargers, but I might go that route as well if it makes financial sense.

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victron quatro inverter but only for 230V not American split voltage.
but you have voltronic or original mppsolar stackable https://www.mppsolar.com/v3/110v-120v-low-voltage-series-2/

Mac2 said:

Thank you! That gives me great perspective. I can only find chargers in the 100 amp range. I guess I’ll look at stacking chargers. I have seen chargers/inverters with higher rated chargers (I think around 200 amps). Not sure why they can’t make larger chargers, but I might go that route as well if it makes financial sense.

Click to expand...

ask this if you know how much AC electric you need if you need for AC unit for example 9000W go with 3 stackable inverter with 300A AC charger https://www.mppsolar.com/v3/110v-120v-low-voltage-series-2/
this is little more expensive 600-800$ pcs good,warrant work little loud but also you have voltronic copy of this unit with 100 ac charger 250-300$

More: your second link was the same as your first. Also, I have the Victron MPPT controllers already, but just haven’t hooked them up yet.

twistedtree said:

I had a Skylla TG on my last boat, and dual Skylla-i on the current boat. The good part is that they reliably put out 100A across all encountered ambient temps. This is in sharp contrast to the charge output from my Quattro inverter/chargers. The Skyllas also have remove voltage sense which I think is mandatory for LFP since a couple tenths of a volt is the difference between charged, and not charged.

The down side is that adjusting the voltages is a royal PITA. You need to disconnect the charger output, disconnect BOTH the pos and neg sense leads (I don't know why you also need to disconnect the neg lead, but I discovered this the hard way), then fiddle with POTS on the circuit board that only responss after you turn them a bit, which pretty much ensures they are always starting from the wrong point. But once sent up, they work well.

The TG is dumb as a stump, which may be preferable over the Skylla-i which is smart enough to be really, really stupid. The TG you can set absorb time to 0 hrs which I think is preferable for LFP - certainly way better than 4 hrs which is the lowest for the TG. The I can be monitored via CAN bus, but it can't really be controlled by a BMS.

Both, frankly, as a disappointment and I hope Victron comes out with new models soon. The up side is that very few people make a 100A 24V charger. I think Mastervolt does, but I don't trust them to get anything right at this point, and support is completely non-existant.

Click to expand...

Thanks. Good to know about mastervolt. I was looking at the Victron products you mentioned. Real life experience you mentioned is invaluable.

Twistedtree: “The TG you can set absorb time to 0 hrs which I think is preferable for LFP - certainly way better than 4 hrs which is the lowest for the TG.”

Which for Skylla-i ?

Mac2 said:

Twistedtree: “The TG you can set absorb time to 0 hrs which I think is preferable for LFP - certainly way better than 4 hrs which is the lowest for the TG.”

Which for Skylla-i ?

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The lowest you can go with a skylla-I is 4 hrs. When controlled via Canbus by an MG energy BMS they do some hacks to improve that, but it’s still not great. The good news is that if you are just using the skyllas for more charge current when running a generator, the absorb time really doesn’t matter because as soon as the batteries are charged, or close to charged, you will turn off the generator and the skyllas will shut off anyway.

Mac2 said:

Looking to replace my old Newmar phase three 24/240 volt battery charger with a high amp LifePo4 battery charger only.
I'm looking at the Victron Skylla-TG 24/100 230v. Anyone have any other recommendations? I want something with at least 100 amps. I have one house bank rated for 1200 amps. My Xantrex inverter/charger only puts out 60 amps. Also, would the two chargers working together get confused with the charge readings? I will try to duplicate the charge cycle, but wondering if this could be a problem.

Click to expand...

when specing battery chargers to LiFePo4 batteries there is self mangered and fully mangered BMS systems, its criticail that you consider this, by far the best battery system is fully managered although most in boat applications seem to be self mangered.
if self managered check the specs with the BMS in regards to its charge and discharge ratings, in the battery world there is a heap of BS from manufactures and suppliers due to competitive nature of the industry.
I am prelexed by why anyone would risk non compliant charging(not saying you are) if thermal runaway happerns it nasty in shore side applications let alone boats.

Frankdog:
I have no idea what you mean by self mangered (I assume you mean “managed”) vs fully managed. I set my inverter/charger to the charge rate specified by my battery manufacturer. Is there something Im missing? I know my battery manufacturer (LifePower Eg4) has changed the bulk charge rate once since I bought the batteries.

Frankdog said:

when specing battery chargers to LiFePo4 batteries there is self mangered and fully mangered BMS systems, its criticail that you consider this, by far the best battery system is fully managered although most in boat applications seem to be self mangered.
if self managered check the specs with the BMS in regards to its charge and discharge ratings, in the battery world there is a heap of BS from manufactures and suppliers due to competitive nature of the industry.
I am prelexed by why anyone would risk non compliant charging(not saying you are) if thermal runaway happerns it nasty in shore side applications let alone boats.

Click to expand...

I didn’t understand these either. Then there is the part about Thermal runaway, while an issue with some Lithium chemistries it really is not an issue with LifePo4 and a decent BMS.

twistedtree said:

I had a Skylla TG on my last boat, and dual Skylla-i on the current boat. The good part is that they reliably put out 100A across all encountered ambient temps. This is in sharp contrast to the charge output from my Quattro inverter/chargers. The Skyllas also have remove voltage sense which I think is mandatory for LFP since a couple tenths of a volt is the difference between charged, and not charged.

The down side is that adjusting the voltages is a royal PITA. You need to disconnect the charger output, disconnect BOTH the pos and neg sense leads (I don't know why you also need to disconnect the neg lead, but I discovered this the hard way), then fiddle with POTS on the circuit board that only responss after you turn them a bit, which pretty much ensures they are always starting from the wrong point. But once sent up, they work well.

The TG is dumb as a stump, which may be preferable over the Skylla-i which is smart enough to be really, really stupid. The TG you can set absorb time to 0 hrs which I think is preferable for LFP - certainly way better than 4 hrs which is the lowest for the TG. The I can be monitored via CAN bus, but it can't really be controlled by a BMS.

Both, frankly, as a disappointment and I hope Victron comes out with new models soon. The up side is that very few people make a 100A 24V charger. I think Mastervolt does, but I don't trust them to get anything right at this point, and support is completely non-existant.

Click to expand...

I hope that the you all don't mind me dropping into the conversation and seeking a little advice.

For my boat, I've installed a Skylla-i as well in my Victron Energy 3 x 5000VA MP-II, Cerbo GX, REC-BMS managed custom CALB-230 2,000 AH house battery, but am not happy with it with how the charger works. The architecture is at least 10 years old and feels that support for the LiFePO4 chemistry is an add on, but that the hardware really is not up to the task.

In the mean time, I am trying to see if I can get the Skylla-i to work well in my system.

I first tried the Rotary switch position 7, but the 28.4v for absorption is too hot for my tastes.

I am using position 8 to set Abs, and Float.





I am still learning the ropes, and my system is new, but I am currently focused on these values Abs: 27.6v (w/2hr), Float: 26.8, Storage: 26.8. (see comment below)

I was able to get the #8 switch position to deliver this with the exception that the dumb-as-a-box-rocks VE programmer's decision to fix storage 26.4v which is too low from my point of view.

I looked at the new MasterVolt 24V/100A charger, but I don't like the options for programing.

So, I too am looking for a better solution. There are some hints from a VE sales manager that they _may_ be updating their "smart" chargers beyond the IP43 24V/25A that I have now as well.

Because I am using only Victron gear, I'd like to have 100A charger with VE.Direct so that I can hook up to the Cerbo GX.

In the mean time, I have the Skylla-i hooked up with the voltage sense wires and am using the Skylla remote control panel.

The Skylla-i manual says that I can connection to the Cerbo GX via the VE.Can bus, it tossed errors. I was trying to connect the Skylla-i control panel to the VE.Can that already supports a WakeSpeed 500, Cerbo GX and the REC-BMS. I can't get VE tech support to respond. Sigh...



If anyone has suggestions of a better charger, I'd like to hear...

Thanks for letting me post into this thread

-Bill

twistedtree said:

I had a Skylla TG on my last boat, and dual Skylla-i on the current boat. The good part is that they reliably put out 100A across all encountered ambient temps. This is in sharp contrast to the charge output from my Quattro inverter/chargers. The Skyllas also have remove voltage sense which I think is mandatory for LFP since a couple tenths of a volt is the difference between charged, and not charged.

The down side is that adjusting the voltages is a royal PITA. You need to disconnect the charger output, disconnect BOTH the pos and neg sense leads (I don't know why you also need to disconnect the neg lead, but I discovered this the hard way), then fiddle with POTS on the circuit board that only responss after you turn them a bit, which pretty much ensures they are always starting from the wrong point. But once sent up, they work well.

The TG is dumb as a stump, which may be preferable over the Skylla-i which is smart enough to be really, really stupid. The TG you can set absorb time to 0 hrs which I think is preferable for LFP - certainly way better than 4 hrs which is the lowest for the TG. The I can be monitored via CAN bus, but it can't really be controlled by a BMS.

Both, frankly, as a disappointment and I hope Victron comes out with new models soon. The up side is that very few people make a 100A 24V charger. I think Mastervolt does, but I don't trust them to get anything right at this point, and support is completely non-existant.

Click to expand...

I identified these as the pots on the Skylla logic board.

twistedtree said:

I had a Skylla TG on my last boat, and dual Skylla-i on the current boat. The good part is that they reliably put out 100A across all encountered ambient temps. This is in sharp contrast to the charge output from my Quattro inverter/chargers. The Skyllas also have remove voltage sense which I think is mandatory for LFP since a couple tenths of a volt is the difference between charged, and not charged.

The down side is that adjusting the voltages is a royal PITA. You need to disconnect the charger output, disconnect BOTH the pos and neg sense leads (I don't know why you also need to disconnect the neg lead, but I discovered this the hard way), then fiddle with POTS on the circuit board that only responss after you turn them a bit, which pretty much ensures they are always starting from the wrong point. But once sent up, they work well.

The TG is dumb as a stump, which may be preferable over the Skylla-i which is smart enough to be really, really stupid. The TG you can set absorb time to 0 hrs which I think is preferable for LFP - certainly way better than 4 hrs which is the lowest for the TG. The I can be monitored via CAN bus, but it can't really be controlled by a BMS.

Both, frankly, as a disappointment and I hope Victron comes out with new models soon. The up side is that very few people make a 100A 24V charger. I think Mastervolt does, but I don't trust them to get anything right at this point, and support is completely non-existant.

Click to expand...

I believe this is the potentiometer https://wmsc.lcsc.com/wmsc/upload/file/pdf/v2/lcsc/2207041730_Nidec-CT-94EX102_C3548241.pdf

Mac2 said:

One of the reasons I want the additional charger is to put a bigger load on my 21kw generator. Im wasting a lot of generator for a 60 amp charger.

Click to expand...

like you charging problem i switch to 48v and 2 x victron multiplus 2 48/5000/70-50

70+70 A 58v charger 8120-8000w in battery