Building a 60v 25 amp manual charger

Thread Starter

Skipperdan

Joined Apr 5, 2019
26
Hello, I want to build a 60v 25 amp charger. I will be using a Honda 2200 inverter generator as power. I want to charge a 60v battery bank between 50% and 80%. The Honda will be able to provide 1,800 watts continuous. I will hope to run it between 30 and 60 min. I have looked at several transformers as well as variable transformers. The 2200 will provide 220v which I think would be best. If I use a step-down transformer then to a rectifier bridge to 73.5 volts DC I should be able to charge the batteries. If I incorporate a cutoff circuit to cut out the charger at 72v the Honda will shut down telling me the charge is complete. The problem I am having is finding a transformer that goes from 220 to 74 volts that also has a 25 amp capability. Could I just make my own or could I use two in a series. I am also not sure how to limit the amps other than limiting the volts to the batteries.

What I am trying to accomplish is; Running the Honda for the least amount of time plus not overcharging the batteries. I have solar that will top them off. Any help would be appreciated, Thank You in advance, Dan
 

MrChips

Joined Oct 2, 2009
21,161
AC voltages are specified with RMS values.
Peak value will be RMS x 1.4
Hence you need 52VAC to give 72VDC.

The you have to factor in the ripple voltage if you are going to use a capacitor bank to smooth out the ripples.
 

schmitt trigger

Joined Jul 12, 2010
246
What Crutschow is asking is: how many cells does the battery bank has? And what battery chemistry are we talking about?

For instance a Pb wet cell bank of 24 cells will have a nominal voltage of 48 volts, but during equalization charging, those will require 2.35 to 2.40 volts per cell. Or 56.4 to 57.6 volts.
 

Thread Starter

Skipperdan

Joined Apr 5, 2019
26
Doing more research I found that an inverter generator uses the 3 phase head rather than a single phase head. This is then rectified to DC then inverted to AC. I am going to see if I can get the 110v DC from the head before it gets inverted and use a regulator to maintain 73.5v. I should be getting 25 to 30 amps to the battery. Then just a simple cutoff once the battery hits 80 to 85% charge.
 

Tonyr1084

Joined Sep 24, 2015
4,554
Still need to know what kind of batteries we're discussing. Five 12V batteries equal 60 volts. Is that what we're discussing? If so - charging them properly will require 69 to 72.5 VDC. That calculation is based on Lead Acid (car) batteries. Typical charging of car batteries is 13.8 to 14.5 volts. Marine (deep cycle) batteries are "Probably" similar in charge voltage requirements, but I have no experience with Marine batteries.

For a thorough answer you need to give us thorough information.
 

Dodgydave

Joined Jun 22, 2012
9,169
If it uses a Star winding with a Neutral, then use half wave rectifier to get lower AC,

What battery type is it, Lead Acid, Lithium, Nicad???
 

Thread Starter

Skipperdan

Joined Apr 5, 2019
26
Still need to know what kind of batteries we're discussing. Five 12V batteries equal 60 volts. Is that what we're discussing? If so - charging them properly will require 69 to 72.5 VDC. That calculation is based on Lead Acid (car) batteries. Typical charging of car batteries is 13.8 to 14.5 volts. Marine (deep cycle) batteries are "Probably" similar in charge voltage requirements, but I have no experience with Marine batteries.

For a thorough answer you need to give us thorough information.
5 deep cell Lead Acid Trojan SCS200
 

Thread Starter

Skipperdan

Joined Apr 5, 2019
26
If it uses a Star winding with a Neutral, then use half wave rectifier to get lower AC,

What battery type is it, Lead Acid, Lithium, Nicad???
Why do I want lower AC? I want DC volts @ 73.5v. If I have 3 phase coming off the head as long as that is over 73.5 it should be able to be regulated to 73.5 just like an alternator, correct?
 

Dodgydave

Joined Jun 22, 2012
9,169
Why do I want lower AC? I want DC volts @ 73.5v. If I have 3 phase coming off the head as long as that is over 73.5 it should be able to be regulated to 73.5 just like an alternator, correct?
Generators are not Alternators, they don't have an Excited winding to generate the field, it will give out either 120V AC or 230V AC, so i would use the lower output voltages and rectify it then feed it into a regulator or buck regulator instead for less heat wasted.

Lwad Acid batteries are charged at 14 to 16V.
 

Thread Starter

Skipperdan

Joined Apr 5, 2019
26
Generators are not Alternators, they don't have an Excited winding to generate the field, it will give out either 120V AC or 230V AC, so i would use the lower output voltages and rectify it then feed it into a regulator or buck regulator instead for less heat wasted.

Lwad Acid batteries are charged at 14 to 16V.
Add 5 together and you get 73.5v.
 
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