# Carging system

Is it possible to charge a 72v system with a 36v charger.

I know we could unhook the battery series in the middle, and wire them in parallel to charge it that way. However that thats allot to do every night.

I was thinking that I could leave the batteries in series, but wire the 36v charger so that it will be parallel to two 36v battery packs.

Good question…

So if you hook 6 - 12v batteries together in series, you make 72v right?

Can you hook 6 - 12v battery chargers in series to create a 72v Charger?

Something tells me no.

Is it possible to charge a 72v system with a 36v charger.

I know we could unhook the battery series in the middle, and wire them in parallel to charge it that way. However that thats allot to do every night.

I was thinking that I could leave the batteries in series, but wire the 36v charger so that it will be parallel to two 36v battery packs.

no, it’l short out, you’d have to have a disconnect in the middle of the pack.

you could make a relay charger, have it switch once every 30 min, so that it’l charge the first half, then switch and connect the second half, and keep switching until its done.

Its actually kinda how we charge our Myers NMG. we have one 12V charger, and have each of the 13 batteries broken out to a plug. There are 13 relays, and it cycles through each battery.

It is possible to charge the batteries while they are still hooked up but you would have to charge them as two packs of 36 volts. One pack at a time. I have a 144 volt system and I had to charge each battery individually with a regular charger at first. as long as you only charge three batteries at once this would be ok. But you would have to manually change the hookup when the three batteries are charged to the three that need charging. I suggest you get a charger that charges them all together as imbalances can occur.

Another option is the use of a boost transformer, I use one to boost the signal 40 volts. It cost me about 100 dollars and is about twenty lbs.
http://www.signaltransformer.com/
Here is a link to thier site there is a phone number there also. They were very helpful and courteous.

[QUOTE=new dawn;4360]Another option is the use of a boost transformer, I use one to boost the signal 20 volts. It cost me about 100 dollars and is about twenty lbs.
http://www.signaltransformer.com/
Here is a link to thier site there is a phone number there also. They were very helpful and courteous.[/QUOTE]

Please point me to the product you used…I have a hard time believing you used one because Transformers don’t work with DC…

so… how did you get yours to work?

Build yourself two wiring harnesses. One that connects the batteries in series for running and one that charges them in parallel. You’ll need a 4 wire female connector and two male connectors. One male will have a jumper to connect the batteries in series for running, remove this connector when charging and replace it with one that is connected to your 36v charger with one wire from the positive charge pole to each positive load terminal and one for each negative. Piece of piss.

Frodus is right. I just called Signal Transformer and they said I have the Model # MPI-900-40 The input is 115 volts or 230 volts AC depending on the configuratation. Output is 40 volts wired in series AC. in order to make this into DC current you need to use a Unfiltered Full Wave Bridge it will produce roughly 36 volts DC. I used a onboard charger the BC-20 and KTA’s Ken was very helpful in telling me which transformer I needed to boost the voltage up and sending a wiring diagram on how to wire it and the needed programable resistor for that voltage which is around 180 volts at peak.D

Hay thanks for all of your responses. I thought that i saw going to have to disconnect them. So I need to disconnected the series in the middle, and set the charger in parallel with two 36v battery packs.

Hay thanks for all of your responses. I thought that i saw going to have to disconnect them. So I need to disconnected the series in the middle, and set the charger in parallel with two 36v battery packs.

[QUOTE=new dawn;4367]Frodus is right. I just called Signal Transformer and they said I have the Model # MPI-900-40 The input is 115 volts or 230 volts AC depending on the configuratation. Output is 40 volts wired in series AC. in order to make this into DC current you need to use a Unfiltered Full Wave Bridge it will produce roughly 36 volts DC. I used a onboard charger the BC-20 and KTA’s Ken was very helpful in telling me which transformer I needed to boost the voltage up and sending a wiring diagram on how to wire it and the needed programable resistor for that voltage which is around 180 volts at peak.D[/QUOTE]

just didn’t wanna confuse him…

Lots of people use a boost transformer to boost the BC series chargers.

How’s it workin for you?

This is kinda what Frodus is talking about I think. A system like this would work pretty easy. the DPDT relay could be hooked to a timer that switches between the two thus charging the entire pack

my thoughts exactly.