Technical Can I replace the lead-acid battery with a lithium-ion battery?

[Mikky500R]

(I'm using google translate.)

Hello

I've been driving a fiat500R in Japan for 15 years.
I don't have much knowledge about cars or electricity, but I'm enjoying it except for one small problem.

The small problem is that the lead battery wears out quickly.
Just charging the dashcam and smartphone
runs out of power.

There are several solutions, but
before replacing the generator with an alternator,
I thought about replacing the battery from a lead battery to a lithium-ion battery.

This is expected to increase the charging efficiency and efficiently charge the electricity generated by the dynamo.
Recently, there are many products the size of a car battery,
so the replacement process seems easy.

Here is the
Redodo 12V 50Ah PRO
Power: 640Wh, Voltage: 12.8V, Size: 195mm*166mm*172mm, Weight: 5.29Kg
● Long life: 4,000+ cycles, 10-year lifespan, 100% SOC and DOD support.
● Powerful BMS protection: Equipped with 50A BMS, provides overcharge, overdischarge, overcurrent and short circuit protection.
● High temperature cut-off: Automatically stops charging above 50°C.
● High power: Maximum 50A continuous charge/discharge current, maximum 640W continuous discharge power.



The particular problem is the load when moving the starter motor.
Does anyone know how much power (W) a standard FIAT500 starter motor consumes?

Also, has anyone thought about and done something similar to me?
What problems did you encounter at that time?

I would be happy if you could share your experience.

Thank you.

 

[the green vanper]

Hello,

The main problem are charging / discharging temperatures for the Li-Ion technology. They are both above zero!

I'd consider a deep discharge battery in your place.

 

[dirkdeman]

The starter on my 126 draws 42A according to the manual, I assume it is the same for the 500. For this reason I'm not a fan of deep discharge batteries as they likely aren't able to crank out 42A all at once.

Now, Li-Ion batteries have a couple of big downsides:

• Much more expensive
• They require a different charging method
• They're really flammable when pierced, especially since it's mounted right in the front of your car where you're most likely to have an accident!

There are a couple of things that you can check:

• Is your battery in good condition?
• Is your dynamo putting out enough voltage (>14V)?
• If so: is your voltage regulator putting out enough voltage?

If all these things are in order than it might be a good idea to swap your dynamo out for an alternator. That's probably an easier and cheaper task than going the Li-Ion route anyway!

One other solution would be to add a second (regular Lead-Acid) battery just for the dashcam/smartphone. You can even add it to the existing charging wiring from the dynamo.

 

[smart51]

Lead Acid batteries take a high current at first but slow down a lot as they fill. A Lithium Ion battery will take whatever current you give it until they get almost full. On boats (Where they have big Lithium batteries) they have special battery chargers that slow the current down after a short time to mimic a lead acid battery. This is to stop the alternator burning out. Alternators will only give full current for a short time without overheating and burning out. Maybe a smallish lithium battery won't cause a problem. I'd find out before buying one.

 

[Mikky500R]

Thank you for your advice.

The dynamo is about 12V when idling, and 13-14V when driving.

I replaced all the wiring about 10 years ago.

I also replaced the lights with LEDs to save electricity.

However,
if I drive while using my smartphone, dashcam, and lights, the battery will wear out.
And it will eventually stop working.
(From now on, it will be a rainy season in Japan.)

I have been worried about this problem for many years since I bought it, but
even when I consulted a repair shop, they said there was no problem,
so I am very troubled.

It is true that, considering the power used by the starter motor and vibration, I don't think a lithium-ion battery is very suitable.

I would like to consider replacing it with an alternator.

However, the capacity of lithium-ion batteries is very superior to that of lead batteries, so I would like to consider using them as a sub-battery.

Thank you for your advice!

 

[the green vanper]

I'm not a fan of deep discharge batteries as they likely aren't able to crank out 42A all at once.

I've checked three or four deep discharge batteries specs right now and all of them have cranking amps like usual lead-acid batteries.

if I drive while using my smartphone, dashcam, and lights, the battery will wear out.

because the receivers use more power than the dynamo is able to produce. When the car was engineered, no one even imagined a smartphone or a dashcam. I'm pretty sure charging your smartphone is the culprit here. If you need it, use a powerbank.

My mum had a 126p with the dynamo when I was doing my driver's licence some 30 years ago, I remember I've put 'standard' 55W headlights bulbs, because the original (35W) were crap and you couldn't see anything, but in the rain the the wipers were struggling to move.

When I got my license we swapped it to the watercooled 126bis with the alternator, it was a huge improvement.

 

[the hobbler]

I've checked three or four deep discharge batteries specs right now and all of them have cranking amps like usual lead-acid batteries.



because the receivers use more power than the dynamo is able to produce. When the car was engineered, no one even imagined a smartphone or a dashcam. I'm pretty sure charging your smartphone is the culprit here. If you need it, use a powerbank.

My mum had a 126p with the dynamo when I was doing my driver's licence some 30 years ago, I remember I've put 'standard' 55W headlights bulbs, because the original (35W) were crap and you couldn't see anything, but in the rain the the wipers were struggling to move.

When I got my license we swapped it to the watercooled 126bis with the alternator, it was a huge improvement.

I think that the change to an alternator would be a better idea , rather than fitting a Lithium battery. Using the 'dynamo' fan-shroud when changing to a alternator IS possible, but it is a lot of hassle---better to try and obtain the shrouding for a 126, at least on the dynamo/alternator side of the fan housing. Be also aware, it will most probably be an "engine out" job to carry out the shrouding change, but I still think that would be the more sensible way to go----and anyway, you shouldn't be using your 'smart-phone' whilst driving!

 

[AnthonyH]

The small problem is that the lead battery wears out quickly.
Just charging the dashcam and smartphone
runs out of power.

There is only a problem if you try to use the dashcam and charge the phone with the engine off.

I'd suggest you only charge with the engine on. That way you're charging with the alternator, not draining the battery.

 

[JumpJet]

I think that the change to an alternator would be a better idea , rather than fitting a Lithium battery. Using the 'dynamo' fan-shroud when changing to a alternator IS possible, but it is a lot of hassle---better to try and obtain the shrouding for a 126, at least on the dynamo/alternator side of the fan housing. Be also aware, it will most probably be an "engine out" job to carry out the shrouding change, but I still think that would be the more sensible way to go----and anyway, you shouldn't be using your 'smart-phone' whilst driving!

If you want to give it a go, here's my "guide" to how I did it. It's a little bit of work to keep the 500 shroud, but not insurmountable.

 

[Djscorchio]

If the lead acid battery is going flat then the power drain from it is greater than the charging. It makes no difference what battery you use, if you take more out than you put in, it's going to drain it. The only difference is the time it takes to drain.

 

[JumpJet]

If the lead acid battery is going flat then the power drain from it is greater than the charging. It makes no difference what battery you use, if you take more out than you put in, it's going to drain it. The only difference is the time it takes to drain.

Does your dashcam have a 'valet' setting that's always on? Constant filming or records with motion/disturbance? That could certainly put a constant drain on it.