Benefit of replacing converter/charger with larger one

If you are running Trojan brand, high antimony 6v or 12V batteries, do a search on their website and read up on the specifications required. They need to be charged to 14.8V to get to 100%, not 14.4V like most charger controllers provide. Iota brand is the exception, it charges at 14.8V in bulk mode. Most of the others don not.

If your are going to equalize the batteries from time to time, the Trojans need 15.5V to do so. All of this to say that running true deep cycle batteries, your needs are different from the average camper running regular group 24 27 or 31 Deep Cycle batteries, where 14.4V is fine.

I would also run a capable 14.8V for Costco or Sams club based GC2 batteries.

smkettner wrote:
If you want a real 60 amps from a PD you better put in a 9280. ;)

My PD9280 puts out 84 amps at max. It varies from 80 amps at start (50% SOC) to 84A then down to about 75A before the battery has charged to within 0.2 volts of the max charge voltage, at which point the current is limited by the cable resistance and internal battery resistance. It's a perfect choice for me, as it can be easily modified to output 14.8 volts (Trojan recommendation) and I love the manual mode control, plus it wasn't expensive.

Mine has been modified, but the current output has not been changed.

On the negative side, it does have a low power factor, it loses max current at low voltage AC (<108 VAC) and it does not have remote voltage sensing or remote temperature sensing. It's output current is not as constant as I think it should be either. It should stay at near 80 amps, not vary up/down by 9 amps. For my application - rapid charging from my Onan gen of four 6 volt batteries, it's perfect, however for more money, there are other good choices that offer features I don't really need.

The current variation has only a minor effect on recharge time, the PF and voltage issues aren't a problem with my Onan gen, the remote voltage is addressed with thick short charge cables and the temp sensing is something I can deal with on a summer/winter basis.

Checked, it is a 3 stage charger so I'd say no.... Go ahead.
Do not know how good a reputation Power Max has (Which simply means I do not know, nothing more) but on paper it looks just fine.

(Actually, my know knowing how good a rep might be a good thing since folks who are unhappy tend to post about it)

Good stuff BFL!!

Check here to see the various types if you missed on that. PM3s and 4s are deck mount. They do make a lower portion only version for various amp sizes and even a full power centre too with a 60 amper in it.

http://www.bestconverter.com/

The PM3s at least the earlier version were like a WFCO for going into "boost" at 14.4 That is, the batteries have to be down to just under 50% or it will kick off at 13.6. This is no problem if you are on shore power of course.

The PM4s like Randy sells are different in that they will go into boost first no matter what and if the batts are already up, it drops to 13.6 after a few minutes (15 min ISTR) similar to the way Iota does it. So that is a much better match for generator charging as when off grid unless you only run the gen when batts are down to 11.9 so the PM3 will go into boost for sure (iffy at 12.1)

The PM3s cost less (boatand rv)than the newer version PM4s, so you have to know what features are worth it for your situation.

I found the location of the present converter/charger and I do not think a PD will fit. The current unit is a Victory and it is long and narrow. I found a Power Max PM3-75 that would fit the space. Any reason I should not get a Power Max?

If you want a real 60 amps from a PD you better put in a 9280. ;)

Hi W8,

Actually PD does make a 70 amp unit.

PD-9270C-70

Depends on what you mean by Larger...

Going from a 55 to a more common 60, is not a change, that is less than 10% and less than 10% is "No change" when it comes to most electronics. IT is also the change I'd recommend.

70 (Well 69) is the maximum recommended (By Xantrex) recharge rate for a single pair of GC-2's in series. And I do not think anyone makes a 70... Damon put an 80 in my rig.

But for you I'd recommend a Progressive Dynamics 9260. No other change need be made. You won't need to upgrade wiring, odds are you won't even need to upgrade any fuses or circuit breakers. With a bigger unit you may have a lot more work to do.

Matt Colie, a 220 amp hour GC220 will absorb 70-90 amperes on a differential of 14.7 to 12.4 volts. The disproportionate charge acceptance is due to electrolyte abundance of the golf car battery. I have charged depleted GC's at 60+ amperes for in excess of 2.5 hours at a charging voltage limit of 14.1

I fully expect to charge the new 8-D AGM I am getting at 120+ amperes max bulk charge rate acceptance.