Converter charger upgrade

[Rjpetr65]

Hi all,

I have an 04 Sunseeker and would like to upgrade my converter charger. I have solar, an inverter and (2) 6V golf cart batteries in series for 210AH total. It seems like it takes a full day of running the generator to get a decent charge on my batteries. I have a Paralax Model 7355 55A converter currently. Any one replace theirs with something better? I prefer a plug and play rather than having to do a bunch of wiring. I don’t want to go up much higher in amperage because my wiring is stock.

[formerFR]

wait.... you have an INVERTER, too?

ok, what make and model is it?
does it include a battery Charger?
what does the Inverter power?

[houstonstroker]

I would give Progressive Dynamics a call. I think the guys name is Randy.

[ependydad]

Originally Posted by houstonstroker

I would give Progressive Dynamics a call. I think the guys name is Randy.

I think you mean call Randy at BestConverter.com and ask about Progressive Dynamics converters.

[houstonstroker]

Originally Posted by ependydad

I think you mean call Randy at BestConverter.com and ask about Progressive Dynamics converters.

Yes, thanks for keeping in line.

[Rjpetr65]

Originally Posted by formerFR

wait.... you have an INVERTER, too?

ok, what make and model is it?
does it include a battery Charger?
what does the Inverter power?

Inverter is really unrelated to the converter charger as it takes battery power and converts it to AC. You have to pull it out of the circuit when the generator is running either with a transfer switch or manually with a manual switch. But to answer your question it is a Power Drive 1500 w/ Bluetooth. Love it. I can turn it on and off from inside the rig.

[MR.M]

Originally Posted by Rjpetr65

Hi all,

I have an 04 Sunseeker and would like to upgrade my converter charger. I have solar, an inverter and (2) 6V golf cart batteries in series for 210AH total. It seems like it takes a full day of running the generator to get a decent charge on my batteries. I have a Paralax Model 7355 55A converter currently. Any one replace theirs with something better? I prefer a plug and play rather than having to do a bunch of wiring. I don’t want to go up much higher in amperage because my wiring is stock.

I would think you could go 65 or 75 amp with out changing the wire size from converter to batteries

[SlowrideHD]

I think your are pulling those two batteries down too far. I'd add two more for a 2S2P hookup.
I have 8 Trojan T-105's in series to a 48volt, 3600 watt pure sine wave inverter on a solar install.

[sailski]

I have seen other posts that it is recommended to use your generator for a couple of hours in the morning to bulk charge your batteries then use your solar to finish the job because once you have completed the bulk charging the amperage drops when the controler switches to the next stage of the charging sequence and that takes much longer.

[babock]

How far is your converter from your batteries and what gauge wire is used between them.?


I not only changed my converter when I added my lithium batteries but I also have the new converter right next to my batteries connected with 4 AWG cable.


My original converter was nearly 20 feet from my batteries. The battery gauge was a lot smaller...likely 10 AWG. The problem is at higher currents, you get so much voltage drop that the converter thinks the battery is charged way before it actually is and reduces the charge current. This causes very long charge times.


Another thing you have to realize, your flooded lead acid batteries are only going to accept around 10% of it's capacity in current so your 210AH batteries are only going to accept around 21A to 25A even with a perfect converter with no voltage drop. This is one of the reasons to go to AGM as you can often charge them twice as fast. Lithium is even faster.

[pgandw]

Babcock has the right idea, even if his figures are off a little.

The max charge rate for a deep cycle flooded battery is 25% of its capacity. Most modern flooded batteries will not accept more than 20%, and then not for a prolonged period. So a 55 amp converter is plenty for your situation.

But all converters are not created equal. To minimize recharge time with flooded batteries, you need to hold bulk charge (14.4V/42 amps) to about 90% SOC. So if you start from 50% SOC, the actual charge rate will taper down to about 20-30 amps after the first 30-60 minutes. All told, with a converter that holds bulk rate, it will take about 3-4 hours to get from 50% to 90%. And it will take at least another 6 hours to get from 90% to 100% at the 13.7V "normal" mode.

Progressive Dynamics converters have the ability to hold bulk mode to 90% SOC, WFCO converters do not. I cannot speak for other converter brands.

Take Babcock's warning about wiring seriously. If you want to push 40+ amps into the battery, you need #6 wire or better between the converter and battery. Otherwise, the voltage drop reduces the charge rate into the battery AND misleads the converter.

Fred W
2019 Flagstaff T21TBHW A-frame with 2 GC-2 Costco/Interstate batteries and a PD 4135 converter