gwatpe
Well-known member
The battery is the key element of the PHEV.
Many forum members have asked about battery performance and there really is little information forthcoming that has been able to identify a way that a typical driver with limited resources can determine if their PHEV has a battery problem.
I have been testing Lithium batteries for over 5 years now. I have many more years experience with Lead batteries before this.
As a battery loses performance it becomes more difficult to recharge, and for a Lithium battery, the constant voltage phase as the current reduces and recharging is stopped takes longer. This is due in part to a higher internal resistance.
I have had the opportunity to drive now three separate PHEV in a five month period. I have recorded every recharge of each time these cars were fully recharged at my home.
One of the PHEV was identified with a battery that was different. This car took about 50 minutes to complete the constant voltage charging phase.
The other two PHEV took about 30-35minutes to complete the same taper current charge. This is consistent with my house Lithium battery of similar capacity and recharging rate.
I would suggest that we are able to check how well the PHEV battery is working with some simple commercially available metering. The type used for checking household domestic consumption would be suitable. The cost of these units that are plugable for appliance power monitoring would be about $30. The power could be recorded manually for the last hour or so of the recharge, only once or so a year. There are logging systems for a bit more money. The measuring has to handle the maximum recharging current.
If an owner thought the battery was under performing, and had some evidence, then the matter could be taken further if needed. Temperature has a big effect on the performance so we have to be objective in the measurements and say test at a 15-20C ambient temp.
On the PHEV I recorded, the battery best performance correlated with the lowest times for the constant voltage taper current recharge phase.
The kWh needed to fully recharge the battery in conjunction with the time taken for the last phase of recharging will confirm if the battery capacity as well as performance in the PHEV are as expected for the ageing of the battery compared to the manufacturer expectations.
This method is more objective and avoids the driving style and terrain and weather aspects that muddy the predicted range estimates that seem to confuse many drivers of how the battery is performing.
As our PHEV age, the battery performance will dwindle and I have a means to check it when needed, without requiring a full battery diagnostic service at the dealer, for additional $$$$.
Many forum members have asked about battery performance and there really is little information forthcoming that has been able to identify a way that a typical driver with limited resources can determine if their PHEV has a battery problem.
I have been testing Lithium batteries for over 5 years now. I have many more years experience with Lead batteries before this.
As a battery loses performance it becomes more difficult to recharge, and for a Lithium battery, the constant voltage phase as the current reduces and recharging is stopped takes longer. This is due in part to a higher internal resistance.
I have had the opportunity to drive now three separate PHEV in a five month period. I have recorded every recharge of each time these cars were fully recharged at my home.
One of the PHEV was identified with a battery that was different. This car took about 50 minutes to complete the constant voltage charging phase.
The other two PHEV took about 30-35minutes to complete the same taper current charge. This is consistent with my house Lithium battery of similar capacity and recharging rate.
I would suggest that we are able to check how well the PHEV battery is working with some simple commercially available metering. The type used for checking household domestic consumption would be suitable. The cost of these units that are plugable for appliance power monitoring would be about $30. The power could be recorded manually for the last hour or so of the recharge, only once or so a year. There are logging systems for a bit more money. The measuring has to handle the maximum recharging current.
If an owner thought the battery was under performing, and had some evidence, then the matter could be taken further if needed. Temperature has a big effect on the performance so we have to be objective in the measurements and say test at a 15-20C ambient temp.
On the PHEV I recorded, the battery best performance correlated with the lowest times for the constant voltage taper current recharge phase.
The kWh needed to fully recharge the battery in conjunction with the time taken for the last phase of recharging will confirm if the battery capacity as well as performance in the PHEV are as expected for the ageing of the battery compared to the manufacturer expectations.
This method is more objective and avoids the driving style and terrain and weather aspects that muddy the predicted range estimates that seem to confuse many drivers of how the battery is performing.
As our PHEV age, the battery performance will dwindle and I have a means to check it when needed, without requiring a full battery diagnostic service at the dealer, for additional $$$$.
