So I spent a lot of money on my battery which I like and am not changing. I just checked my notes and said I should be within range if I run the upper limits constant at 55 amps both 12 or 24v power supplies according to Howard. So I know I at least had the dc max at 55. I think I forgot to change the battery side to 55. So it was at 60. You think I would be ok just dropping it down to 55? Again I really like my setup and this is really frustrating. I don't want a generator. I could run 2 power lab 8's or a dual but than I would have to get another charging box and spend more money I don't have. Not to mention my car is jammed back as it is.

I run my 2688 watt Dual Power lab off of a meanwell 48 volt power supply rated for 42 amps or basically 2kw. I power the whole affair from a Yamaha 2kw generator. Since these systems are only as strong as the weakest link my generator rated for only 1600 watts continuous at sea level is by far my weakest link at 5500' MSL. IME the PS voltage drops and the charger trips out if I try and charge 4 6S 5000 batteries at more than 10 amps, 2C, per battery. This is only about half of what the charger is rated for.

You're running a single powerlab 8 so your requirements are a little different but as Judge said your charger is still only rated at 612 watts when run off of 12 volts. As others have also stated any battery you might use will drop well below 12 volts under significant load. I've tried using various 12 volt batteries and never had good results when drawing high currents.

These very high power capable chargers have solved part of the problem for those of us running big electrics but they must be fed high DC voltages to run at maximum potential. Much as I hate to be the bearer of expensive news you simply are not providing enough energy off any 12 volt battery to deliver the performance you paid for. Two batteries giving you 24 volts will help but I maintain that the best solution remains a robust generator powering an equally robust DC power supply. As a matter of fact many of our high power charge setups are already pushing the boundaries of what 120vac can provide on a typical 20 amp circuit driving us towards the use of 240.

You've already been given the answer you might not want to hear

High power electric flight can be a lot of fun but speed costs money. Good luck

Cub,
without spending any more money, your only choice is to slow down your charge rate and not parallel charge several 6s packs at once at greater than 1c.

So the amount of power the charger can handle is half of its max at 12v less 10% efficiently loss? I do agree a generator is the best route, however one of the clubs I fly at does not want it where I want to charge and I just really like the battery route. If I got another charger (I know this is not the most practical) and limited both to 45 amps, it would potentially pull 90 amps from the battery and would certainly drop the voltage down more on the battery, but is it feasible at least from the charger side?

Originally Posted by Cryhavoc38

Cub,
without spending any more money, your only choice is to slow down your charge rate and not parallel charge several 6s packs at once at greater than 1c.

Agreed. If the OP does not want to change his system to something more appropriate for his charging needs, then he needs to lower his charge rate. I would monitor actual battery voltage and charge high enough to keep the battery level around 12.2VDC or higher.

Plus you are going to find out that even a good 12V marine deep cycle is not going to hold enough voltage under load to do many charges at the field. You are not going to get 55 amp hours of it in a charging use, plain and simple.

Why would Revolectrix give you the option of 60 amps if it can't handle it?

Ok so back to my last post, I do drop the marine battery down later in the day probably around 11.6v lowest. I can charge enough for one day. My question is if I keep my current setup what is the MAX current I should have the battery side set at without ruining the charger???

Just because your speedometer goes to 120 do you drive at 120?

Best bet is to get another battery and run 24V if you want to keep a battery setup as your power source. Double your voltage and cut your current in half.

FWIW, I use a 2kw generator and 1800 Watt dc power supply. This coupled with two PL6's is enough to keep me flying continuously and there's no pesky marine battery to take care of.

Originally Posted by supercub1

Why would Revolectrix give you the option of 60 amps if it can't handle it?

Ok so back to my last post, I do drop the marine battery down later in the day probably around 11.6v lowest. I can charge enough for one day. My question is if I keep my current setup what is the MAX current I should have the battery side set at without ruining the charger???

depends on what you are charging.
you haven't mentioned, that I have seen, what size packs you are charging at the field, and how you are charging, ie single or parallel.

FYI, the PL 8 spec is
Continuous max output power: 612W @ +12VDC input, 1344W @ +26.35VDC

You are limited to a max of 612w at 12v input.

According to their web page, the PL8 V2 has a max 40amp continuous charge capability

Using +26.35VDC to +32VDC input, 1344W output will deliver full current rating (40A) over the full range of output voltage up to 33.6V

Here is the full spec. Perhaps you were confused by the 60amp input versus the specification of a 40amp output rating.

Input current: 1A to 60A, software limited

Power conversion: Synchronous DC/DC converter, supports multiple switcher frequencies of 31.25 kHz, 62.5 kHz, 125 kHz; user selectable by preset, 85% to 93% efficiency depending on output current

Output battery charge current: Adjustable range 10mA to 40A, limited by 60A input current*

6 cell batteries parallel 3300-6200mah depending on what I am charging. If it can't handle 60 amps what can it handle? There should be more built into the charger than 60 amps that it allows. If the charger can only handle say 45 amps than it should not allow 60 amps on a battery setting?

Ok so 53 amps x 12.6v which is around what the battery starts at I think gives me 667.8 watts which if you multiply x 2 you get 1335.6 watts. That's under 1344 watts? So set the charger on battery mode to 53amps max vs 60?

I understand your trying to figure out watts but there is charger settings you can set to tell the charger what max amperage you can pull for DC/Battery. DC is set I think at 55 amps so I don't overload the Revolectrix power supply and battery was set at 60 amps. I can drop that down to a specific amount. I need this amp number as I will probably keep my current setup.

Originally Posted by supercub1

6 cell batteries parallel 3300-6200mah depending on what I am charging. If it can't handle 60 amps what can it handle? There should be more built into the charger than 60 amps that it allows. If the charger can only handle say 45 amps than it should not allow 60 amps on a battery setting?

Talk to either progressiverc, or the folks at Powerlab again.
I'm out, you do as you wish. You have already been given sage advice from several members.

Originally Posted by jamesrxx951

Fyi old school battery testing is using a carbon pile load meter. Even under 100 amp draw you can drop well under 12V.

Carbon pile variable load -
Haven't heard of those in decades......your showing your age or im get'n old...
One of the best if not the best form of variable resistive loads, depending on crossectional area they can handle some current and then some

Originally Posted by Cryhavoc38

Talk to either progressiverc, or the folks at Powerlab again.
I'm out, you do as you wish. You have already been given sage advice from several members.

I have 2 PL6's and 1 PL8. They have been the work horses of my fleet for years now. Not sure what you are doing that is cause the failures. I used to run big (700 class) helicopters and never had issues... I did however nuke several 24V power supplies. I leaned the lesson quickly that you are only as good as the power being supplied to it. Did you tell the PL's that they are hooked to a lead acid battery without a power supply and to stop charging if they power dips too hard?

Originally Posted by rooman

Carbon pile variable load -
Haven't heard of those in decades......your showing your age or im get'n old...
One of the best if not the best form of variable resistive loads, depending on crossectional area they can handle some current and then some

I'm not that old. But we have one at work. That one is old. I prefer a Midtronics battery tester but if I am really suspicious about a battery I will pull that out after the Midtronics test it. The Midtronics is always right.