2nd battery

One of these days, when I was talking with David Larson from Husaberg in Sweden, he teach a very good tip for better estarting for ours pre 04 bergs. Install a 2nd battery in series with the main one which performs 24V. These 24V is only at the starter as the 2nd. batery is linked between the starter and the solenoid. See the attached diagram. I have tried and the estart now spins like a turbo and the bike starts cold.

If the battery is in series how does the
charging system cope with it? Have you
tried it in parrallel to double the amperage?

Awesome job Husby!!!!!!!!!!!

Including diagram!!!!!!!!!!!

To print Husby's wiring diagram in a larger format:

Go to his gallery and expand the picture
Copy the www. address
Paste it in the address bar
Print from there.


Now if someone would just make an underseat battery box to fit a YTZ10S

TJT

if i remember my old college days well enough, if you charge one abttery it well level itself out with the second till they're equal.

hope i got that right.

regards

Taffy

Taffy,
Don't think so, only if batteries are wired parallel. Charge can only go to the one battery. Trucks used to use a 24/12 system, 24 for starting, run on 12 but they used a series-parallel switch which enabled charging all the batteries. Was great when they worked but wasn't unusual for the switch to go bad.

If memory serves me, someone else on this site described doing something similar to this over a year ago & he got nailed for it????

The second battery does not get charged at all in this arrangement, but by adding about 50 bucks worth of bits you could make it happen.

i still think i'm right. if you put a charged battery next to a flat battery and connect them they 'balance out' when parked up. so the nextt time you start the bike you are charging the first battery but every time you park up the second one gets some...

boy i've hung myself now... :? :?

regards

Taffy

Taffy i think he said the two batteries are only joined when the starter is used did Dale say that the reason for hard starting had more to do with the weak stator out put at starter speed than anything else if so a stator rewinder sent me a transformer and diagram after talking to him about the problem i have used it to boost up a klx 300 i fitted a starter too it seams to be helping and it has boosted the input to the cdi by 20-30 volts you connect the transformer to the alternator wires when the starter is used a relay connects the transformer to the stator wires to the cdi/coil thus boosting the voltage i have used it in the past to boost the source coils on the old yamaha trikes they would pull start every time with little effort but would not start on the button even when a booster battery was used and the starter was 100% the transformer has several input wires and output wires you can swapp these to get the best voltage while i am on the subject after weeks of soaking and sraping i finaly got down to the charge and pulse windings on a burnt out stator i took it to the rewinder which lives 300 miles away talked to him face to face showed him the windings and he laughed at who ever had designed the stator said it would be a waist of man hours to fix it he had in fourty years of m/c coil work never come accross wire so fine he said to invest in another ignition this guy makes peak voltage meters for the bike shops over here and works with honda nz and yamaha before i left i had him agreeing to design and build me a inverter to power the cdi/coil using the sem trigger the trigger seams to last longer than the charge coils . I have in only two years of working on a few husabergs replaced 6 sem stators all of these still had working triggers and alternator windings so ill wat and see what he comes up with

The main charge circuit do not charge the second battery, as it not in the charging circuit and only at the estart. I don't know if the battery charges when we charge the main one (I suppose not) but as when you hit the button is jus a few seconds, I suppose it cope a day at the races and at night you can carge it with the garage charger. This info as gived by David. :wink:

Taffy said:

if you put a charged battery next to a flat battery and connect them they 'balance out' when parked up.

Click to expand...

At a pinch what Taff said was correct for batteries connected in parallel, but the state of charge of the two batteries still doesn't balace out fully.

In the system shown above the batteries are used in series so that you can get close to 24V fed to the starter while cranking. Under the arrangement shown the second battery does not get charged.

I was serious about only needing a few fairly cheap components if someone wants to use the above arrangement AND charge both batteries from the bike electrical system.

Several companies make isolated DC to DC power converters. You feed a DC voltage into a little solid state block (in this case 12 to 14V from the usual bike battery) and it feeds out a DC voltage (I'd suggest a unit of 15V output @ perhaps 2 to 5 watts). The unusual thing about these DC to DC converters is that neither of the output wires is connected directly to the input wires - the two DC voltages can be isolated from each other. It effectively allows the two batteries to run with different ground voltages ie the negative of one battery can run at the positive voltage of the other - exactly what happens when connected in series. Post if anyone wants more info.

not a general post

Moved to electrical.

thanks,
json

ok further to this link.
So, my big issue was 'how to charge the second battery'
Thought I would post this and see what you thought. I have not done it yet...before you ask !

Regards
Ady
See Drawing attached

Just found this interesting link about running a 12v motor on 24v for a short period of time.

Somebody dissuade me - Or i'm going for it !!!

Regards
Ady

http://www.4qd.co.uk/faq/bmnc1.html

That should work, but you have to make sure that the diode can handle the 12V reverse bias from the battery nearest the starter, if it can't it will break down and will then conduct.

Thanks Kzoo and Hi

I'm not sure i would even need it though (hence the question mark underneath it on my drawing), as there is not one in the complete line from the rectifier to the main battery anyway.
I don't see how there can be any reversed bias as both battery's will have parrallel connections across each terminal in their normal riding/charging state.
BTW. I intend on upgrading the charge fuse if necessary to allow for the extra amperage for charging maybe up it 1 amp.

do you agree ?

Regards
Ady

Ok, now that I look at it again that makes sense...

Does anybody know the current rating for the recitifier?

2 Amp rings a bell ?
It's one in the morning here, a bit late to get my meter out, but will check it out when i can.
It may not even be an issue, because i will have the advantage of continually charging both battery's even when i connect my optimate charger to one set of terminals when not riding the bike. Therefore with battery's in tip tip condition, less current will be required to charge during riding.
BTW I also have a 100 switch in my main battery leg, this stops any drain and isolates the battery when charging through the optimate.

Regards
Ady

Ady
This will almost work but is a bit clumsy as shown. With a couple of small mods it would work well.

Relay 2 would need to be a double pole changeover relay that is capable of handling full starter current - about 150A. It would be like a starter solenoid but with two independent sets of contacts that connect one way when the relay is not pulled in & the other when it is.

Assuming you could get one, you should completely remove the existing starter relay as its function is accomplished by the new changeover relay.

Also you would not need the diode - in fact it would prevent the second battery charging properly in the current configuration because you always lose about 1 volt across a diode. Reverse breakdown is not an issue at such low voltages.

When you lose the diode you normally have both batteries connected in parallel - quite OK from charging and running point of view. You could probably go down in battery size if it helped fit 'em in.

kzoo said:

Does anybody know the current rating for the recitifier?

Click to expand...

13A @200V for Semikron SKB25/02