How do you wire up battery charger?

[Mobilesport]

I have 1996 Express van 
2 gc2 golf batteries
Battery isolator 
L.e.d lights are wired up to house battery

I added a Powermax Boondocker battery charger model bpcm-75 
I power it from Honda 2000 and run positive from charger to positive golf battery and the negative from charger to negitive on the golf battery , it worked for about 2 months but always acted kinda goofy once in a while and then The charger went dead , sent charger back under warranty and they fixed it , I hook the charger up and first time I go to use it the power is on but its not charging and then it finally kicks on .
Second time I use it it doesn't do anything and I just left the generator running and the charger powered on and all of the sudden after about 11 minutes the charger kicks on and starts charging.
I know all my batterys and electronics are wired correctly but am I doing something wrong , for example can my electronics stay wired up while charging or do I have to isolate them from the charger?
I should add this model of charger is also a convertor so I don't see why I wouldn't be able to leave the electronics on while charging.

 

[B and C]

Others here will probably be better help than I am.  What Ga wire and how long a wire from the charger to the batteries?

Chart:


This is for the length of the positive and negative cables added together, ie.  2 ft. positive + 2 ft. negative = 4 ft

I would look at the crimp ends also.  If they have gotten hot due to a poor crimp, they would have stretched the crimp making it electrically loose.  After the charger is on for awhile, the connection heats up again making the connection good again.  This is just a guess from me over the internet.

 

[Mobilesport]

@ B and C   , I have 5 ft positive wire and a 5 foot negative wire , both are 4 gage.

 

[SternWake]

Sorry to hear of these issues with the powermax.


This is the adjustable voltage version, correct?

If so, this one does not have any 'stages' of charge commonly called bluk, absorption/float. It seeks to bring the battery to the voltage chosen and will hold the battery at that voltage as long as it is plugged into a generator/115vAC.  It is in effect a one stage high amp manual charger and not to be treated or considered an automatic charger

The Fan might take some time to actually come on, as the heatsink inside of it must reach a certain temperature before it will start spinning.  The fan itself might not even come on if the batteries only require very little amperage to bring and hold the battery at the voltage selected, meaning they are not discharge much at all.

Operation of the fan is not necessarily indicative as to whether the charger is operating properly.

However when the batteries are depleted, they should be able to ask for large amperages and if drawn to 50%, then they will ask for all of the 75 amps the powermax should be able to produce and the fan should come on fairly quickly, unless it is outdoors and with low ambient temperatures.

So Unless you know your batteries are discharged, and you know for a fact that no amps are making it to the batteries( Do you have an Ammeter?)
you can;t really know if the charger is actually operating properly.  But voltage can indicate if it is operating, if the voltage rises.

So what is the battery voltage when you hook up the powermax?

What voltage have you set the powermax to?  This voltage needs to be set without the battery hooked up to the DC output.  You cannot accurately adjust voltage when it is hooked to a depleted battery as the battery will drag the voltage down until they attain high states of charge.

One should put a piece of masking tape next to the potentiometer dial and mark an indicator for 14.8v and for 13.6 and 13.2v, and then one does not need to set voltage unloaded then reattach to battery.  These setpoints 'might' drift after the first use where the unit is at max output for a period of time and might require a second calibration.

If this is not a manual, adjustable voltage version, but is the 3 or 4 stage automatic version, the output voltage it will seek when plugged in depends entirely on battery voltage when first plugged in.  if batteries are discharged only slightly it will likely seek only 13.6 or 13.8v, but if down at 12.2v when plugged in, it should seek 14.4 or 14.6 depending on the specific model and the amperage maxed out at 75 amps.

The thickness and length of the DC output cables has a huge effect on the stages the automatic units will choose, with long and thin leading to issues and short and fat maximizing its potential.  Also the cable size on the manual adjustable voltage version will also play a big part in how fast the batteries recharge.

So, there might just be some misunderstanding of how this charger operates at different levels of battery state of charge.  The fan itself is not an indicator, you need a digital multimeter to see if voltage rises, and an Ammeter if you want to see how much current is required to bring the battery upto a certain voltage.

You do not need to isolate any DC electronics or other charging sources when using this unit.  It can easily both power the DC loads while charging the battery, which is also a DC load.

The size of the DC load, reagrding battery charging, is determined by the battery itself, how depleted it is.  If you are not discharging the batteries much at all then very little amperage is required for it to rise to the voltage setpoint you have chosen.

If indeed it is operating improperly then I apologize if you bought this unit on my recommendation, and hope Errin Tribble at powermax makes it right.  It is very hard to diagnose the improper operation of these over the phone as their appearance of malfunction can be related to battery state of charge.  If the batteries don't need much as they are not discharged much, then the charger might appear to be inoperable when in fact it is just a marathon runner sitting in a lounge chair eating bon bons waiting for the marathon to start.

 

[Txjaybird]

Sorry to hear of these issues with the powermax.


This is the adjustable voltage version, correct?

If so, this one does not have any 'stages' of charge commonly called bluk, absorption/float. It seeks to bring the battery to the voltage chosen and will hold the battery at that voltage as long as it is plugged into a generator/115vAC.  It is in effect a one stage high amp manual charger and not to be treated or considered an automatic charger

The Fan might take some time to actually come on, as the heatsink inside of it must reach a certain temperature before it will start spinning.  The fan itself might not even come on if the batteries only require very little amperage to bring and hold the battery at the voltage selected, meaning they are not discharge much at all.

Operation of the fan is not necessarily indicative as to whether the charger is operating properly.

However when the batteries are depleted, they should be able to ask for large amperages and if drawn to 50%, then they will ask for all of the 75 amps the powermax should be able to produce and the fan should come on fairly quickly, unless it is outdoors and with low ambient temperatures.

So Unless you know your batteries are discharged, and you know for a fact that no amps are making it to the batteries( Do you have an Ammeter?)
you can;t really know if the charger is actually operating properly.  But voltage can indicate if it is operating, if the voltage rises.

So what is the battery voltage when you hook up the powermax?

What voltage have you set the powermax to?  This voltage needs to be set without the battery hooked up to the DC output.  You cannot accurately adjust voltage when it is hooked to a depleted battery as the battery will drag the voltage down until they attain high states of charge.

One should put a piece of masking tape next to the potentiometer dial and mark an indicator for 14.8v and for 13.6 and 13.2v, and then one does not need to set voltage unloaded then reattach to battery.  These setpoints 'might' drift after the first use where the unit is at max output for a period of time and might require a second calibration.

If this is not a manual, adjustable voltage version, but is the 3 or 4 stage automatic version, the output voltage it will seek when plugged in depends entirely on battery voltage when first plugged in.  if batteries are discharged only slightly it will likely seek only 13.6 or 13.8v, but if down at 12.2v when plugged in, it should seek 14.4 or 14.6 depending on the specific model and the amperage maxed out at 75 amps.

The thickness and length of the DC output cables has a huge effect on the stages the automatic units will choose, with long and thin leading to issues and short and fat maximizing its potential.  Also the cable size on the manual adjustable voltage version will also play a big part in how fast the batteries recharge.

So, there might just be some misunderstanding of how this charger operates at different levels of battery state of charge.  The fan itself is not an indicator, you need a digital multimeter to see if voltage rises, and an Ammeter if you want to see how much current is required to bring the battery upto a certain voltage.

You do not need to isolate any DC electronics or other charging sources when using this unit.  It can easily both power the DC loads while charging the battery, which is also a DC load.

The size of the DC load, reagrding battery charging, is determined by the battery itself, how depleted it is.  If you are not discharging the batteries much at all then very little amperage is required for it to rise to the voltage setpoint you have chosen.

If indeed it is operating improperly then I apologize if you bought this unit on my recommendation, and hope Errin Tribble at powermax makes it right.  It is very hard to diagnose the improper operation of these over the phone as their appearance of malfunction can be related to battery state of charge.  If the batteries don't need much as they are not discharged much, then the charger might appear to be inoperable when in fact it is just a marathon runner sitting in a lounge chair eating bon bons waiting for the marathon to start.

i want to thank you for such an informative post on the use of battery chargers.  while i'm still a " arm chair  van dweller" at this time....  i've had vans/t.t's/ pickup+campers in the past.  i keep a file of posts that will help when i'm able to start a build of my own.  and thanks to others on these forums who freely share their experiences with everyone.    happy trails     texas jaybird

 

[Mobilesport]

@ Sternwake
Thanks for taking the time.
Yes its the adjustable. 
I normally set it at 14.8v  but for some reason the voltmeter reading drops down to 13.6 after about 14 minutes ,, I thought it was supposed to stay at were I set it .

Battery voltage is 11.9 volts right now 

My furnace runs the batteries down every day to the point were my furnace tells me theres not enough battery voltage

I did put a piece of masking tape on the charger and marked the 14.8v and 13.6 v locations.

After making the marks alot of times when I started to adjust the knob I go by  the voltmeter  still but it but it would line up with the mark.

E.g  I adjust knob until voltmeter read 14.8v and the knob lines up with the mark on the masking tape .

There definitely is a misunderstanding on how this charger works ,, they sent me no operational manual , I requested one and still nothing .
There is no  manuals or info for this model on the Bestconvertor website

Thanks again for all the help

 

[SternWake]

I am very sorry to hear this as it appears to be malfunctioning.

Does the fan also shut down or seem to not spin as fast as it should?
If you can direct more airflow through the converter, does this 14 minutes seeking 14.8v last a little while longer, perhaps indicating overheating?

Are you checking the DC voltage with another meter? The voltmeter they include did not much impress me. ( My friend has a 100 amp version).

Is this on a generator? Can you check AC Input voltage, or plug into the grid to see if perhaps it is AC input voltage related?

If you twist the voltage dial to the maximum, does it respond? How about voltage unhooked from battery( unloaded)?

Can you notice any heating on the output terminals, smell anything funky like overheating electronics?

I feel bad for having recommended this product. They do have a 3 year warranty, but if bought from Randy at best converter.com expect him to duck your calls, which is why I recommend people bypass this middleman and goto Errin directly at Powermax, but unless they take care of you with some quality customer service and an apology, I will never recommend their products again.

My apologies.

 

[SternWake]

One thing that is a remote possibility is the battery resistance when first hooked to a depleted battery.

When i feed 40 to 65 amps into my 90AH AGM depleted to ~ 50% and below, this 65 amps has voltage rise fairly quickly to 14.4v, but then as the battery wakes up from this high amp blast, the voltage then drops, but only to 13.8v or so, and then slowly climbs back upto 14.4v at which points the amps are tapering.

So it is pretty important to see amp flow, as if your trojans behave similarly with a high current source, first applied, this Might be an explanation as you do not know the amps flowing at the voltage.

I know this is a reach, I am not personally familiar with the behavior of t-105s at these higher charge rates. A sulfated battery can quickly rise in voltage with big currents applied, where as an unsulfated battery's voltage will slowly rise while maxing out the charger.

If you can answer these questions and present this data to Errin proving that it is not operator error or sulfated batteries he is more likely to honor warranty quickly rather than a 'send it to me and we'll check it, maybe' while you have no other charging source.

Again, my apologies this has occurred if it was my product recommendation which put you in this spot between the rock and hard place

 

[Mobilesport]

@Sternwake
To answer our questions. 
1 I'm not sure about the fan.
2 I cannot direct more air flow , unit is dead know.
3 nope , I'm using the volmeter they Include. 
4 yes on generator
5 nope , no grid Im boondocking.
6 before it died , sometimes it used to respond to moving the voltage dial but even then it acted like it was struggling , voltmeter reading didn't want to go up but sometimes it finally did , sometimes it wouldn't do anything. Play with the dial and you may get it to start working but got to the point were it wouldn't do anything at all , ever.
7 unhooked from battery ,,,, voltmeter reads nothing (blank)
8 I felt the wires many times but no heat on wires ever ,,,, inside the unit was warm.
9 yes , I did smell hot electronics but not real strong .

 

[Mobilesport]

@Sternwake

Starting when I first got the boondocker charger
Whenever I first started up the Boondocker I always set it to 14.8 volts but after about 14 minutes the voltmeter reading would drop to 13.6 volts and my generator would start running quieter like all of the sudden it isn't doing as much work. 
It was like this for the first 2 months I used the charger.
My batteries were not getting charged even when charging for 2----3 hours.
So I seeked help.
I was told the reason my batteries aren't getting charged is because the Boondocker charger is dropping the voltage down way to soon.
I started thinking that the boondocker shouldn't be dropping the voltage down at all because its supposed to stay were I set it , but it doesn't and never did since the first day I had it.
Anyways after getting the info that the charger was dropping the voltage down too soon I came up with a idea , I'll set the boondocker to 14.8volts and since I know its gonna drop down to 13.6 volts after about 14 minutes I'll set my timer on my phone for 14 minutes and when it goes off I'll turn the boondockers voltage dial back up from the 13.6 volts until it reads 14.8 volts.
Worked like a charm and for the next month and a half my batteries were charged everyday and then my furnace would run them down everyday and I just would do this process again everyday. 
Then charger started acting up even worse and then died completely. 
I sent It back under warranty and Erin got it to power up again but still the same issues with voltage dropping off after 14  minutes and then died right away this time

 

[SternWake]

Well the unit certainly sounds Kaput.  Sorry to hear you are without a dedicated  high amp charging source.  Do you have any other method of charging or are you in the proverbial canoe without a paddle, and heat.

The hot stinky electronics smell one expects on the first run or two at max output should have dissipated long ago, so any stink now is a failed component internally.

I hope exercising the warranty, again, is not some cluster screw of effort.

Can you get the batteries upto 80% or above just so the sulfates do not harden to the point that aggressive EQ cycles are not required to redissolve them.  Jumper cables to engine battery?

I wonder if your generator's voltage is in spec and the sine wave nice and clean.  Has any other device protested on its output?

 

[Mobilesport]

I'm just charging with alternator now , and then I only use furnace while the van is running.
Run van 10 minutes every other hour or less if I can get away with it.
Reminds me of the importance of a back up charger



Nope no protesting