New converter sizing recommendations

[bogen2]

I am upgrading my 12v converter/charger and would like to get some feedback on how to choose the right one. I have a 200w solar charger, but the sun doesn't aways shine so need another way to charge the batts.

I want to be able to minimize charging time when hooked to a generator - I am going to buy either a 2000W or 3000W Champion. Would prefer the 2000W model due to its smaller size, but would consider the 3000W just to speed up the charge time if it would make a real difference.

The converter I have is the older IOTA 45A that doesn't have the port to add the IQ4 "smart" charger. I have 2 6V "Costco" batteries and have upgraded the converter charge wire to 10 gauge. I have been looking at the Powermax converters but I'm not sure which model would be best for my needs, although I would be open to suggestions of other manufacturers.

[racer4]

bogen2 wrote:


The converter I have is the older IOTA 45A that doesn't have the port to add the IQ4 "smart" charger.

Iota says you can still add the IQ4. "If you are using an IOTA DLS Battery Charger that does not feature a Dual Voltage Jack, you can still attach an IQ4 Smart Charge Controller to your system...just contact IOTA's Customer Service Department for assistance.

IQ4 page link Scroll to the bottom.

So ... if it helps, you should be able to charge faster with the IQ4 and your current converter.

[BFL13]

bogen2 wrote:

BFL13 wrote:

IMO leave the Iota in place as your shore power converter, and get a stand alone charger for fast charging off the generator. IMO your best bet is the PowerMax 75 amp adjustable voltage model so you can set 14.8v on it and that will be perfect for your two 6s.

The 75 is PF corrected so it will run on a 15a circuit with a 2000w generator. (The PD9280 is not PF corrected and needs a 20a circuit and it has charging profile issues, although not as bad as some)

Regular converters of the PowerMax, Iota IQ4, PD w CW all have charging profile "issues" so it is important to get the adjustable voltage one. It is more expensive, but think of it as being like two 40a VEC1093DBDs at $150 each for cost comparison.

Will the Iota be sufficient to properly recharge the batteries on shore power? I have never seen it get over about 13.5v.

I have a B&D 40a charger (like the VEC) that I use to service my batteries. Would that be a better choice for quick recharges on generator power?

The Iota will run the rig and maintain the batteries when you are on shore power. The trick is to get the batteries fully charged first so they stay that way. I use my VEC for that to get them to 14.6v after getting home with low batteries and then leave the bank on the converter. Hit them with 14.6 every two weeks with the B&D to stir them up (de-stratify) if they are sitting a long time.

You can use the B&D 40a on the two 6s for fast charging and you don't need to do anything else. Problem solved.

For reducing the gen time even more, you could use two of those 40 ampers at once. 80a is near the practical limit for fast charging a 220AH bank, but you don't cut the time in half by doubling the amps.

Using Vectors on a 220AH bank to do "50-90s" I measured times at:

70 amps- 129 minutes (two 35 ampers at once)
55 amps- 139 minutes (a 35 plus a 35 at 20)
35 amps- 177 minutes (single 35)

[bogen2]

Bump, with the hope of getting answers to my followup questions.

TIA...

[bogen2]

Chandalen wrote:

I am assuming they are on a 10-20' run and about 8ga so fast math...

a. 15' at 13.5v with 8 ga wire @50 amps = 12.56v at destination
b. 15' at 14v with 8 ga wire @50 amps =13.06

If you rewired... lets say another 8ga wire for two per pole::

a. 13.03
b. 13.53

Or with 4ga wire

a. 13.13
b. 13.63

So even with #4 wire the charger will still never get above 14v?

[bogen2]

BFL13 wrote:

IMO leave the Iota in place as your shore power converter, and get a stand alone charger for fast charging off the generator. IMO your best bet is the PowerMax 75 amp adjustable voltage model so you can set 14.8v on it and that will be perfect for your two 6s.

The 75 is PF corrected so it will run on a 15a circuit with a 2000w generator. (The PD9280 is not PF corrected and needs a 20a circuit and it has charging profile issues, although not as bad as some)

Regular converters of the PowerMax, Iota IQ4, PD w CW all have charging profile "issues" so it is important to get the adjustable voltage one. It is more expensive, but think of it as being like two 40a VEC1093DBDs at $150 each for cost comparison.

Will the Iota be sufficient to properly recharge the batteries on shore power? I have never seen it get over about 13.5v.

I have a B&D 40a charger (like the VEC) that I use to service my batteries. Would that be a better choice for quick recharges on generator power?

[bogen2]

MEXICOWANDERER wrote:
QUESTION
How distant are your batteries from the Iota?

The batteries are about 20 feet away. And after checking the charging wire, its actually #8.

[Chandalen]

+1 for changing the converter to battery wires first. Its really shocking how much more power you get just by changing the wires.

You could have the most top of the line charger but the wire size will still screw everything up.

EDITED>> I saw you have 10ga wire.... That makes things worse..

a. 15' at 13.5v with 10 ga wire @50 amps = 12.00v at destination
b. 15' at 14v with 8 ga wire @50 amps = 12.50

There is no way your charging any batteries properly.


I am assuming they are on a 10-20' run and about 8ga so fast math...

a. 15' at 13.5v with 8 ga wire @50 amps = 12.56v at destination
b. 15' at 14v with 8 ga wire @50 amps =13.06

If you rewired... lets say another 8ga wire for two per pole::

a. 13.03
b. 13.53

Or with 4ga wire

a. 13.13
b. 13.63

[filthy_beast]

Unless the converter is close to the batteries where you can upgrade the wiring, I would not increase the output of the converter. You hear a lot about the RV builders skimping on quality leads me to believe they did not oversize the charging circuit wires. Even going to a 55 amp from a 45 amp is an increase of nearly 20 percent.

[BFL13]

bogen2 wrote:
I am upgrading my 12v converter/charger and would like to get some feedback on how to choose the right one. I have a 200w solar charger, but the sun doesn't aways shine so need another way to charge the batts.

I want to be able to minimize charging time when hooked to a generator - I am going to buy either a 2000W or 3000W Champion. Would prefer the 2000W model due to its smaller size, but would consider the 3000W just to speed up the charge time if it would make a real difference.

The converter I have is the older IOTA 45A that doesn't have the port to add the IQ4 "smart" charger. I have 2 6V "Costco" batteries and have upgraded the converter charge wire to 10 gauge. I have been looking at the Powermax converters but I'm not sure which model would be best for my needs, although I would be open to suggestions of other manufacturers.

IMO leave the Iota in place as your shore power converter, and get a stand alone charger for fast charging off the generator. IMO your best bet is the PowerMax 75 amp adjustable voltage model so you can set 14.8v on it and that will be perfect for your two 6s.

The 75 is PF corrected so it will run on a 15a circuit with a 2000w generator. (The PD9280 is not PF corrected and needs a 20a circuit and it has charging profile issues, although not as bad as some)

Regular converters of the PowerMax, Iota IQ4, PD w CW all have charging profile "issues" so it is important to get the adjustable voltage one. It is more expensive, but think of it as being like two 40a VEC1093DBDs at $150 each for cost comparison.

[MEXICOWANDERER]

QUESTION
How distant are your batteries from the Iota?

[time2roll]

I don't recommend Powermax because they drop to float as soon as they hit the 14.6 set point and leave you with maybe 75% charge and a slow crawl to 90+%.

I would tend to stick with IOTA as that is what you have and they are very good.
Probably 45 or 55 amps is plenty with the IQ controller. Will work fine on 2000+ generator.

Sorry to say but I that #10 is a bit thin for fast charging. #10 will get warm to hot with 50 amps flowing. I recommend #4.
http://www.genuinedealz.com/marine-wire/marine-battery-cable?cat=39


Plan on running the generator 2 to 3 hours to get from 50% to 90% battery charge.