Battery charging

[richie2]

Hi
As posted under "General" I am a (delighted) new owner and this is my first post. I want to store my NSX in the garage for weekend use and so keep the battery topped up. I have a Halfords charger, which firstly charges the battery and then maintains the charge i.e. delivers a trickle charge. I have a classic 911 which rarely sees the light of day and have simply hooked the battery terminals up to a charger / trickle charger for years with no issues.

But! the NSX Handbook states " Charging the battery while it is connected can seriously damge the car's controls" I do not want to remove the battery as it messes with lots of settings, radio, etc.

I originally intended to use the jump start terminal and an earth point, but that Handbook warning has spooked me.

Any thoughts?

Richie

[exiges1]

My CTEK charger is always connected to the battery terminals, never caused any problems, well none I know of! The CTEK is a battery charger and conditioner and is designed to be connected to the battery for long periods. I also have a Halfords charger but only use it for short (an hour or so) periods.
The more technically minded will be along to advise I'm sure.
Driving it regularly is of course probably the best method of keeping the battery topped up.

[Kaz-kzukNA1]

Hi, Richie.
Welcome to the forum and congratulations on becoming the owner.


There is a difference between charging and conditioning.

When charging the battery, like you let the battery flat, you are meant to disconnect it before start charging.
It all depends on the equipment you use but some of the cheap products don’t have good constant current control circuit causing surge current that may damage some of the controllers on the car.
Though, most of the key components such as ECU, etc on Honda cars are well protected.
From this point, classic cars like our NSX is better than the modern cars that may fail even by just jump starting it.

Also, depending on the battery type you use, it will generate gas that may cause small explosion if left close to any spark so again, highly recommended to remove the battery off the car before charging.

And most importantly, ordinary battery has limited life.
The battery may fail while you are charging it and again, depending on the equipment you use, it may not stop charging even when the battery started expanding, etc.
Therefore, car manufactures have to warn the customers.
To be on the safe side, once getting to like 8 – 10 years point, you may want replacing it with a new one and keep existing one as an emergency spare.
Some owners are using these spare battery connected in parallel to the car if they don't have power supply at where the car is stored.


On the other hand, conditioning is different.
It needs well designed constant current control circuit and under conditioning mode, the actual current is very low, unlike the charging mode.
Some of the devices on the market have fail-safe mode against battery failure or abnormal temperature of the device itself.

So, as long as you invest in the well-known good quality conditioner (not charger), you are very likely to be fine.
Just remember that ordinary lead-acid battery will sooner or later fail and it could happen while not only charging but also during conditioning mode.
Super capacitor is not there yet although advancing very quickly.


Many owners are using the products from CTEK, TecMate (Optimate, Accumate, etc), etc and leaving it for months on their NSX.
You can also install permanent connection as well.

Kaz

[richie2]

Thanks for this guys. I will have a look to see if the battery is sealed or if it is the older type that needs the caps to be taken off the cells to allow gas to escape. I may invest in a sealed unit anyway.

If I remove the battery what will I lose on the electrics side? Radio, clock etc? I also dont fancy the alarm taking a hissy fit. So leaving it connected is my favoured option.

[goldnsx]

I've a CTEC on a gel battery (Odyssey 680) directly connected to the battery/car for 11 years now and it's still very good. I guess I'm getting 15-20 years out of it. If your Halfords is comparable you can leave it on for the time you don't drive it. That's what I do. If you're worried about the battery acid I can recommend the Odyssey 680 gel battery.

If you loose the terminals you have to set the radio stations and the clock once again, nothing else.

[richie2]

Thanks.

Okay some fairly dumb questions;
How do I tell if it is a sealed battery? You can hardly see it as it is tucked away. but I dont see any of the old style "caps".

Also, is taking the battery out difficult? I am not the best of mechanics. It looks a bit tricky for my pathetic skillset.

[Pride]

Thanks.

Okay some fairly dumb questions;
How do I tell if it is a sealed battery? You can hardly see it as it is tucked away. but I dont see any of the old style "caps".

Also, is taking the battery out difficult? I am not the best of mechanics. It looks a bit tricky for my pathetic skillset.

I know you've just spent a good few bob in buying the car recently but my suggestion is to replace it with an OEM Honda battery designed for the car and then you know exactly where you stand with the battery condition and warranty (they're only about £60)👍

And if you want to keep costs down just buy an auto shut off battery charger from halfrauds for less than £50, connect it up when parked up in your garage at the engine bay jump lead connector point and forget about it, just like your 911.

I've been doing exactly that for nearly 20 years with no problems on my 92 NA1.

CTec are good but suspect reliability in my experience, they always seem to go wrong soon after the warranty finishes and I've had at least 3 or 4 over the years.:(

[gcon45]

I've used a CTEK for maintenance charging on my NSX with the battery in situ for over 7 years now with no issues.
Just make sure to disconnect before turning the ignition on.
As Kaz says disconnect the battery for recovery charging.

[richie2]

Thanks. I think it is an OEM Honda Battery, you can just see the sticker. As for CTEK I've had two and they both failed so not for me!

[gcon45]

Thanks. I think it is an OEM Honda Battery, you can just see the sticker. As for CTEK I've had two and they both failed so not for me!

Strange. I have 3 CTEKs that I rotate around various cars and motorbikes, the oldest of which is 10 years old. They all still work perfectly. Are you sure you didn't drop yours or even just blew a fuse?

I have sold loads of them and have only seen one faulty one. Well, I say faulty. It looked like it had been driven over, reversed over and parked on.

[richie2]

No definitely not dropped them, they just decided to stop working. Might just be coincidnce, who knows? Anyway I am sorted and now have a plan! Battery is sealed and stays in place, trickle charge clamped to jump start terminal and an earth, good to go.

[Pride]

Strange.
I have sold loads of them and have only seen one faulty one. Well, I say faulty. It looked like it had been driven over, reversed over and parked on.

I too used to sell them, in fact every time I sold an Optima battery nearly every customer bought one, the number of complaints from failures after the warranty had run out was incredible. Too fragile in my opinion when moved around.

[Kaz-kzukNA1]

Just make sure not to confuse yourself between sealed and MF (Maintenance Free) battery.
Not having the 'cap' doesn’t mean it's sealed battery.
Honda battery is MF, not sealed type.

There is also glass mat, AGM, wet or whatever it's called that doesn't have fluid slashing inside the cell like the ordinary lead acid battery.
These tend to survive much longer.
I use AGM from Panasonic on MX5.
It's the OEM one and lasts easily more than 10years.

There are many fake CTEK units with poor electronics components inside on the market.
If you don't like it, you can get the one from TecMate.
They are sold under the product name such as OptiMate, AccuMate, etc.
Used by many race teams and I think they started mainly targeting the motorcycle market but now expanded to the larger capacity batteries.

Any way, seems like you are sorted now so please keep driving regularly. Good for your battery as well.


Kaz

[havoc]

Another recommendation for CTEK - used one ever since I bought my car over 7 years ago, and I only needed a new battery when I forgot to connect the CTEK after a winter drive and realised >3 weeks later (5/6y.o. battery by that time).

[The King]

I've had a CTEK for 10 plus years. It has seen a lot of use. I cycled it between four rarely or not driven vehicles this past winter. It has spent numerous winters on the S2000, and was used extensively for years at a dealership to recondition dozens of depleted batteries in new and used vehicles. I only need to use it on the S2000 for a day or so every few weeks in the winter, as that car doesn't seem to have the same kind of draw as the NSX. I have a Battery Tender wired with a quick plug in that car.

[richie2]

Thanks for all of the advice. All hooked up and led is a green. Its a sealed Honda Battery so should be okay. Still intend to drive it when the weather get better though!