wiring 36 volt

[procraftmark]

I was going to a 36 volt system and was wondering if there was a way to charge the tm 3 and the start batt off of a 3 bank charger?



thanks

[CatFan]

Yes, you can add a switch to either parallel the cranking battery with a TM battery or you can switch the charger once the TM batteries are done which is probably the better option if you want to do it that way. There are some problems involving the noise reduction circuit in some MK motors though.

Best answer is to just buy a single bank charger to add to the cranking battery and use a short Y cable to allow you to plug them both in with one cord.

[procraftmark]

how would you switch the charger once the 3 tm were done with it being wired,unless you move the leads? which would be a real PIA lol

[Lou r Pitcher]

Paralleling differently discharged batteries for charging is not good for obtaining full battery life.

DPDT switch able to handle directing the full output current of the charger bank does the job.

[Ann-Marie]

Paralleling differently discharged batteries for charging is not good for obtaining full battery life.

<SNIP>.

Why do you think "Paralleling differently discharged batteries for charging is not good for obtaining full battery life."? Do you have some research? Our empirical experience, especially for 24 and 36 volt batteries in series is that battery life can be doubled by equalizing the charge in parallel so they discharge uniformly and the "good" ones don't force current through the "weaker" ones and destroy them.

A Trollbridge 36 will charge all 3 trolling batteries in parallel from a single output charger on the starting battery and also charge them every time your outboard is running. That makes the switching automatic and by reducing depth of discharge battery life can be doubled.

[wmitch2]

Why do you think "Paralleling differently discharged batteries for charging is not good for obtaining full battery life."? Do you have some research? Our empirical experience, especially for 24 and 36 volt batteries in series is that battery life can be doubled by equalizing the charge in parallel so they discharge uniformly and the "good" ones don't force current through the "weaker" ones and destroy them.

A Trollbridge 36 will charge all 3 trolling batteries in parallel from a single output charger on the starting battery and also charge them every time your outboard is running. That makes the switching automatic and by reducing depth of discharge battery life can be doubled.

Love my Troll Bridge !! I've gone 3 days fishing and never plugged in to recharge ANY of the batteries !1

[procraftmark]

how does this get 4 batteries charged off of a 3 bank charger

[Lou r Pitcher]

how does this get 4 batteries charged off of a 3 bank charger

Use a DPDT switch. After one battery is fully charged throw the switch and charge the other battery.

[Ann-Marie]

If you already have a 3 bank charger and are installing a Trollbridge 36, just connect all 3 charging lines to the starting battery to charge all 4 batteries.

[lpugh]

There are two problems with a trollbridge in that I will not use that method and all should aware of. It may or may not cause users issues. I will not risk it though

1. Alternator on outboards are not designed for the very high output need to charge more than one battery. Charging three or four will cause the alternator to charge at a much higher amp output causing a lot more heat in the stator windings, thus you may have premature alternator failures

2. Sharing the output with other batteries may actually cause the cranking battery to be weaker at the end of the day causing low voltage alarms

Proper batteries, properly maintained will be more trouble free in the long run. KIS..... Keep It Simple

[Ann-Marie]

There are two problems with a trollbridge in that I will not use that method and all should aware of. It may or may not cause users issues. I will not risk it though

1. Alternator on outboards are not designed for the very high output need to charge more than one battery. Charging three or four will cause the alternator to charge at a much higher amp output causing a lot more heat in the stator windings, thus you may have premature alternator failures

2. Sharing the output with other batteries may actually cause the cranking battery to be weaker at the end of the day causing low voltage alarms

Proper batteries, properly maintained will be more trouble free in the long run. KIS..... Keep It Simple

Wrong on both counts, Leon.

1. The Trollbridge 36 has a load limiting feature that limits the alternator output to a safe level. While diode isolators or direct connection charges the LOWEST battery first and can draw excessive current into a low voltage battery, the Trollbridge 36 monitors the load and shuts the current off as needed to give the alternator time to cool if needed. In 25 years of supplying our charging systems, all with unconditional warranty, we have never had a return due to alternator damage.

2. Wrong again, the Trollbridge 36 waits until the starting battery is over 13 volts before it starts to charge the trolling batteries so the starting battery is never below 13 volts. If the voltage drops below 13, the Trollbridge 36 turns off. It gives priority to the starting battery and if it has low voltage the Trollbridge will never turn on.

Before you post negative comments on commercial products you should have the courtesy to CHECK YOUR FACTS.

[CatFan]

Wrong on both counts, Leon.

1. The Trollbridge 36 has a load limiting feature that limits the alternator output to a safe level. While diode isolators or direct connection charges the LOWEST battery first and can draw excessive current into a low voltage battery, the Trollbridge 36 monitors the load and shuts the current off as needed to give the alternator time to cool if needed. In 25 years of supplying our charging systems, all with unconditional warranty, we have never had a return due to alternator damage.

2. Wrong again, the Trollbridge 36 waits until the starting battery is over 13 volts before it starts to charge the trolling batteries so the starting battery is never below 13 volts. If the voltage drops below 13, the Trollbridge 36 turns off. It gives priority to the starting battery and if it has low voltage the Trollbridge will never turn on.

Before you post negative comments on commercial products you should have the courtesy to CHECK YOUR FACTS.

There is no doubt that routing power to the TM batteries based on cranking battery voltage alone results in less charge in the cranking battery. Voltage alone cannot tell you the charge state of a battery during use or charge. The only thing battery voltage above 13V tells you is that the battery is not so deeply discharged that the alternator can't raise the voltage to 13V. Any battery in reasonable condition will measure above 13V when charging regardless of state of charge.

Most of the time in a bass boat the cranking battery will read more than 13V while the outboard is running, and most of the time in a bass boat the cranking battery is very much in need of a charge. There is no way to identify the rare occasions when the cranking battery is at full charge by measuring its voltage alone. This is the fundamental problem with all such charging systems. They redirect current that is needed by the cranking battery and send it to the TM batteries.

[lpugh]

No I am not wrong, I could point out your flawed view by your very own response but I wont go into it further, I stand by my statement in some will experience negative issues. Fifty three year of experience in electrical and charging systems. I know my facts in this subject matter quite well. Do you really want me to go into this in depth?