Using a tool battery as a small motorcycle starting battery?

[maydaverave]

I have been trying to find a small starter battery for my little 400cc yamaha xs cafe racer. I bought a motorcycle starter battery that was just a small 4s lipo which died the first time the headlights drained it. Huge waste of money. It worked great but with no lvc the headlights kill it in a couple mins. Simetimes 1979 motorcycles take several tries to start. I have a kick start back up but one mistake will kill the battery permanently. I bought a much cheaper rc 4s lipo battery but same problem. I'm thinking the lithium power tool batteries are designed to be fully drained without harm. Should i go with a 12 volt or a 14 volt? Any ideas or input or constructive criticism appreciated.

 

[maydaverave]

My charging system runs at a steady 14.6 volts. I mustly use kickstart but the starter pulls 100 hundred amps for a couple seconds. If i only use kickstart thats fine. I would use a capacitor but i need a battery because i upgraded to electronic ignition.

 

[dogman dan]

The tool battery should have a bms that would prevent damaging past 100% discharge.

However, that same bms would almost certainly prevent a 100 amps discharge as well. No drill pulls 100 amps. I could be wrong, but usually a bms has a high amps cut off, which also acts as a fuse in case of a short.

 

[wineboyrider]

Best bet is lifepo4 , because a 4s lifepo4 is closer to a 12v sla battery. I have seen some instructables that show you how to build a motorcycle battery using a123 batteries.

 

[gogo]

A123 cells in at least 2P and a low voltage alarm?

I set my buddy's bike up with a small SLA in the normal circuit and a 2P A123 on a relay for starting. He can also use a boat-battery switch to bring the A123 into the circuit for charging or redundancy. The SLA can recover from 0V, lithium not so much.

 

[maydaverave]

The tool battery should have a bms that would prevent damaging past 100% discharge.

However, that same bms would almost certainly prevent a 100 amps discharge as well. No drill pulls 100 amps. I could be wrong, but usually a bms has a high amps cut off, which also acts as a fuse in case of a short.

I'm fine with only using kickstart. I just need a durable, cheap, compact batter that will work with 14.6 volt cahrging current. Doesn't have to fully charged 80% give or take and will last longer. It's frustrating, all the "motorcycle starter batteries" are crappy batteries that cost five to ten times to much.

 

[wineboyrider]

I use a hobbyking lifepo4 pack in my Honda elite and it is lighter and better than the stock sla and cheaper.

 

[maydaverave]

I use a hobbyking lifepo4 pack in my Honda elite and it is lighter and better than the stock sla and cheaper.

How long have you been using it? Ever completely discharge it? On my other bikes overdischarging isn't a problem but my 1979 xs400 is quirky at best. I have replaced and rewired most of the electrical system but it still has some gremlins. Has anyone come out with a cheap easy lvc yet?

 

[gogo]

I use a hobbyking lifepo4 pack in my Honda elite and it is lighter and better than the stock sla and cheaper.

How long have you been using it? Ever completely discharge it? On my other bikes overdischarging isn't a problem but my 1979 xs400 is quirky at best. I have replaced and rewired most of the electrical system but it still has some gremlins. Has anyone come out with a cheap easy lvc yet?

I read somewhere that those Yamaha ignitions need 1-2 amps to excite the generator coils. If its a '79 the headlight is on with the ignition, so if you're leaving the headlight on that means the generator coil is on, too. Unless your battery LVC circuit has a reset breaker function, it might be stuck below the LVC threshold when you need it. Your motorcycle won't start without juice to the generator coils.

I've been dead in the water with the same type of electrical system on an RD400. The best solution I could figure out is to have an SLA as the primary battery combined with a redundant battery for those occasions when the primary gets drained. The SLA has its life shortened every time it goes flat, but it can recover many times. An SLA or a lithium can be used for the redundant battery.

If you put the redundant battery on a relay/solenoid, it normally kicks in during electric start only. Then if you get a boat battery (A or B, A+B) switch you can take the drained battery out of the circuit and use the redundant battery (select B) to start the motor. After the motor is running, select A+B to charge the dead SLA for a few minutes before switching back to it (select A).

This provides a contingency for leaving the ignition on unintentionally and it works great unless you forget to put the battery switch back to A and then drain (A + B) flat. I added an idiot light to remind about (A+B) selection.

If your bike doesn't start up on first kick you might want to check the ignition coils. The stock coils were notorious for becoming weak.

 

[maydaverave]

I use a hobbyking lifepo4 pack in my Honda elite and it is lighter and better than the stock sla and cheaper.

How long have you been using it? Ever completely discharge it? On my other bikes overdischarging isn't a problem but my 1979 xs400 is quirky at best. I have replaced and rewired most of the electrical system but it still has some gremlins. Has anyone come out with a cheap easy lvc yet?

I read somewhere that those Yamaha ignitions need 1-2 amps to excite the generator coils. If its a '79 the headlight is on with the ignition, so if you're leaving the headlight on that means the generator coil is on, too. Unless your battery LVC circuit has a reset breaker function, it might be stuck below the LVC threshold when you need it. Your motorcycle won't start without juice to the generator coils.

I've been dead in the water with the same type of electrical system on an RD400. The best solution I could figure out is to have an SLA as the primary battery combined with a redundant battery for those occasions when the primary gets drained. The SLA has its life shortened every time it goes flat, but it can recover many times. An SLA or a lithium can be used for the redundant battery.

If you put the redundant battery on a relay/solenoid, it normally kicks in during electric start only. Then if you get a boat battery (A or B, A+B) switch you can take the drained battery out of the circuit and use the redundant battery (select B) to start the motor. After the motor is running, select A+B to charge the dead SLA for a few minutes before switching back to it (select A).

This provides a contingency for leaving the ignition on unintentionally and it works great unless you forget to put the battery switch back to A and then drain (A + B) flat. I added an idiot light to remind about (A+B) selection.

If your bike doesn't start up on first kick you might want to check the ignition coils. The stock coils were notorious for becoming weak.

i might just have to get a cheap 5 or 8 amp hour lipo. The lipo i have now went dead for a few seconds but i trickle charged it overnight. Seems good no puffing. It's an extremely naked bike, no room for lead acid. Maybe nicad, they like going dead.

 

[wineboyrider]

Don't drive the CH150 much anymore, but it holds charge really well and fired it up today to see if it holds charge and it does. I do check the cells with a cell log and it seems to work fine. I have a 4400mah battery and it cranks way better than a sla?

 

[gogo]

i might just have to get a cheap 5 or 8 amp hour lipo. The lipo i have now went dead for a few seconds but i trickle charged it overnight. Seems good no puffing. It's an extremely naked bike, no room for lead acid. Maybe nicad, they like going dead.

Good idea. If you don't use the starter, the battery can be about half capacity. The RD used a 5.5Ah FLA.

 

[spinningmagnets]

RV parts supply companies have dual-battery 12V circuits systems available. This is a common problem. (admittedly, I don't know the best solution).

Contact supower111 (http://stores.ebay.com.au/SuPower-Battery) and ask them to spot-weld together a pack made from Samsung 20R cells. 4S/2P (eight sells) for 50A peak, 4S/3P (12 cells) for 75A peak.

Personally, I would go for 4P / 100A (16 cells) temporary peak amps. I've taken shits bigger than 16 cells.

 

[maydaverave]

RV parts supply companies have dual-battery 12V circuits systems available. This is a common problem. (admittedly, I don't know the best solution).

Contact supower111 (http://stores.ebay.com.au/SuPower-Battery) and ask them to spot-weld together a pack made from Samsung 20R cells. 4S/2P (eight sells) for 50A peak, 4S/3P (12 cells) for 75A peak.

Personally, I would go for 4P / 100A (16 cells) temporary peak amps. I've taken shits bigger than 16 cells.

Good idea thanks.