Solar Panel trickle charger for OBD

[welland]

On 7/23/2020 at 3:50 PM, Herbie said:

Then this chart may help you decide:

Is there a way to read the Battery voltage on any of the screens in the car (rx400h)? It is slightly tedious to get out my multimeter to read the Battery under the bonnet.  

[ColinBarber]

11 minutes ago, welland said:

Is there a way to read the battery voltage on any of the screens in the car (rx400h)? It is slightly tedious to get out my multimeter to read the battery under the bonnet.  

see this video which shows voltage part way through. If you are in Ready mode then the Battery is being charged so the voltage will be higher than checking with a meter. 

 

To get out of the service menu, press and hold the audio power button for 10 secs until the system reboots.

[Britprius]

It perhaps should be noted that a discharge level of 50% is considered a deep discharge, and any thing above that level of discharge is likely to cause damage to the Battery. Also AGM batteries have a slightly higher cell voltage compared to flooded batteries of around 0.1 volts increasing the fully charged 12 volt Battery voltage to 14.2 plus volts.

John.

[welland]

On 8/31/2020 at 10:16 AM, welland said:

Wondering if another solution is to fit an additional small battery somewhere discrete - in the boot to boost storage capacity.  

Or.....

Jump starters are widely available and I believe that these contain a Battery which is connected the the car's own 12v Battery with jump leads.   Thing is, these jump packs are designed to turn a starter motor and we don't need that much power to start our RX400Hs, do we?

So, how much power do we actually need (how little could we get away with)?  Assuming that the 12v car Battery is not fully discharged, I'd think "not much" is needed as a boost.   I wonder what is the smallest jump pack available?  Could a small Battery provide sufficient boost through the cigar lighter........?

[ColinBarber]

2 hours ago, welland said:

So, how much power do we actually need (how little could we get away with)?  Assuming that the 12v car battery is not fully discharged, I'd think "not much" is needed as a boost.   I wonder what is the smallest jump pack available?  Could a small battery provide sufficient boost through the cigar lighter........?

You cannot use a power outlet/cigar lighter to connect an external power supply to the vehicle as these are on the Accessory circuit which is engaged by a relay - you need a permanent live to power the relay. They are also 15 Amp protected which may be enough but you would need to be careful that the auto lights/wipers, interior lights, radio etc were all switched off otherwise you might draw too much power and blow the fuse.

OBD2 socket has a permanent live but is protected by a 7.5 Amp fuse which is very likely to blow.

[Steve_S]

So, I agree with the conclusions of this thread that the AA branded solar car Battery charger is essentially useless.

Not very chuffed that if I have to leave my IS300h parked up for more than a couple of weeks I can almost guarantee it will be dead to me as has now happened again recently and several times over the past year.  

[sylm_2000]

So I have invested in AA solar Battery, followed by 10W Solar Battery Charger and then an expensive jump starter Battery and a trickle charger during lockdown. 

My view is that solar panel chargers less than 20w (combined with decent sun availability) are pretty much useless and will not be able to sustain average 2w of discharge each day by RX450.

I found the jump starter Battery packs the most helpful. A small amount of charge is required for a flat Battery. A decent choice on amazon, I can recommend if you're interested. Lastly the most trusted solution remains keeping a trickle charger connected to the Battery as that would ensure health and safe charge level for the AGM Battery. See if you can buy a charger which has setting for AGM Battery (most don't).

I was advised by the AA man to replace Battery, visited the Lexus dealership for a replacement and was advised against it. It was only a flat Battery and hence maintaining charge was recommended given the limited use of car these days. Any new Battery would end in the same situation if the charge is not maintained.

 

 

 

[Steve_S]

I'd be interested in your recommendation for the jump starter Battery pack, thanks. A bit tired of having to bother my otherwise helpful neighbour.

I had the car serviced in the summer and discussed the problem with Lexus. They advised the same as your dealer. 

[ColinBarber]

14 minutes ago, Steve_S said:

I'd be interested in your recommendation for the jump starter battery pack, thanks. A bit tired of having to bother my otherwise helpful neighbour.

I had the car serviced in the summer and discussed the problem with Lexus. They advised the same as your dealer. 

Something like this:

https://www.halfords.com/motoring/battery-maintenance/jump-starters/noco-gb20-500a-jump-starter-721880.html

Doesn't need to be high capacity for a hybrid.

 

However you don't want to be in the situation where you need to use it. At that point you are deep cycling your Battery and it will deteriorate each time you do it. You need to periodically charge it long before the voltage drops to the point where you cannot operate the vehicle. Ideally an intelligent trickle charger permanently connected but otherwise connect a charger at least once a week, or put the vehicle in Ready mode for 30+ mins at least once a week.

[sylm_2000]

1 hour ago, Steve_S said:

I'd be interested in your recommendation for the jump starter battery pack, thanks. A bit tired of having to bother my otherwise helpful neighbour.

I had the car serviced in the summer and discussed the problem with Lexus. They advised the same as your dealer. 

I bought both from amazon - this is the link for the trickle charger https://www.amazon.co.uk/gp/product/B07ZNL3MC4/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1

and the Battery jump starter was from Yaber (newer model to what I purchased) - https://www.amazon.co.uk/YABER-Starter-20000mAh-Portable-Flashlights/dp/B08V5JX44J/ref=sr_1_5?dchild=1&keywords=battery+booster+jump+starter+yaber&qid=1611856451&s=automotive&sr=1-5

I also tried 10W Solar Charger connected via the OBD port, not very helpful as the discharge rate exceeds the charge rate of the solar panel.

 

Hope this helps.